at Save the Water | April 28, 2024

Researchers are harnessing light energy with photocatalysts to remove harmful pollutants from wastewater. Clean drinking water is a basic human right, yet water pollution remains a pressing global challenge. Traditional wastewater treatment methods often fail to address emerging contaminants and persistent pollutants. By leveraging the power of light and catalysts, photocatalysis offers a sustainable and effective approach to purifying water.

What is Photocatalysis?

Photocatalysts are materials, especially semiconductors like titanium dioxide and zinc oxide, that accelerate chemical reactions under light irradiations. When photons of sufficient energy strike the photocatalyst surface, electron-hole pairs are generated.  This initiates redox reactions that degrade organic pollutants and disinfect waterborne pathogens. Versatile and efficient photocatalysts harness solar or artificial light to drive these reactions, thus offering a renewable and eco-friendly solution.

Applications of Photocatalysis in Water Treatment

Photocatalysis has diverse applications in water treatment, including the removal of organic pollutants, disinfection of pathogens, and degradation of complex contaminants. Photocatalytic oxidation can effectively degrade organic dyes, pharmaceuticals, antibiotics, pesticides, and industrial chemicals. It also leads to the mineralization of pollutants into harmless byproducts. Furthermore, photocatalytic disinfection offers a chemical-free approach to water sterilization, mitigating the risks associated with conventional disinfection methods like chlorination.

Recent Developments

Recent advancements in photocatalysis focus on enhancing catalyst performance, exploring biodegradable and cheaper versions, and optimizing reactor configurations. For example:

• Researchers from Brazil came up with a greener photocatalyst based on a biopolymer known as Gellan Gum. Titanium dioxide nanoparticles mixed with Gellan gum degraded a toxic dye, Methylene Blue, from wastewater with 95% efficiency. It was used three times to treat wastewater.
• Research groups also found that metal elements like lanthanum and iron can form composites with titanium dioxide. These composites can better remove harmful antibiotics like tetracycline from polluted water. They can degrade tetracycline with a 99.1% degradation rate within two hours.
• A study showed that zinc and nickel oxide nanoparticles can also remove harmful dyes from water in the presence of visible light rays. This study’s results concluded that adding zinc to the nickel oxide nanoparticles increased its degradation efficiency up to 92%.
• Indian researchers came up with a cost-effective and eco-friendly photocatalyst. They made Kaolin clay-based nanocomposites with zinc oxide nanoparticles. Garlic peel was used to extract zinc oxide nanoparticles. It can degrade methylene blue via photocatalysis with 96% efficiency within two hours.
• By growing layers of bismuth oxybromide on clay beads or aggregates, a floating catalysts was prepared. It can effectively degrade two drugs, ibuprofen and diclofenac, to carbon dioxide and water by using solar light. Since it remains on the water’s surface, we can easily remove and reuse it. Moreover, clay beads do not harm water quality as well.

Advantages and Challenges of Photocatalysis in Water Treatment

The advantages of photocatalysis in water treatment are manifold:

• Photocatalysis offers complete degradation of pollutants with minimal use of chemicals.
• It exhibits broad-spectrum activity against various contaminants. 
• It is a simple, convenient, reusable and cost-effective technique.
• The recent design of biodegradable clay-based photocatalysts has given them an added eco-friendly advantage.

However, challenges such as the need for optimal light conditions, less efficiency, lifespan, and stability of photocatalysts hinder its widespread implementation. Addressing these challenges is crucial for realizing the full potential of photocatalysis in water treatment. Developing novel photocatalytic materials, reactor designs, and operational strategies can help tackle these challenges.

Future Outlook

Looking ahead, it is clear that photocatalysis is a sustainable solution for water treatment. Interdisciplinary research collaborations, technological innovations, and policy support will drive its continued evolution and adoption. Together we can pave the way towards a sustainable and resilient water future.

at Save the Water | March 17, 2024

 A new study uncovered that boiling tap water could remove at least 80 percent of three of the most common microplastics usually found in tap water. This finding may mean that drinking boiled water is likely better for your health than bottled water. People in several East Asian countries already drink boiled water. This practice solves the increasing harms of microplastics. Just last month, researchers found that bottled water can contain up to a quarter-million fragments of nanoplastics per liter.

Although some advanced water filtering systems can filter microplastics from water, this relatively expensive solution remains an inaccessible method to many. In contrast, boiling water before drinking it offers an inexpensive way of ensuring that the water supply is clean and safe. Moreover, it only takes five minutes to get such positive results. 

How Did Researchers Discover the Benefits of Boiling Tap Water?

The study was published in ACS Publications: Environmental Science and Technology Letters. During the study, researchers used samples of “hard” tap water. “Hard” tap water refers to water that has a high concentration of minerals, such as calcium carbonate. The researchers proceeded to contaminate these water samples with nano and microplastics.

When the researchers boiled the water, the calcium carbonate formed a solid chalky substance called limescale. Limescale is a natural way of trapping the plastic particles that were in the sample. After boiling, you can remove this limescale using a simple coffee filter and remove the trapped plastic particles.

Health Hazards Caused by Microplastics and Nanoplastics

Microplastics and nanoplastics penetrate almost every aspect of our lives, which makes them extremely difficult to avoid. They are also small in size, making them difficult to spot and filter out. That said, why were the researchers worried about microplastics and nanoplastics to begin with?

Simply stated, several health hazards result from overexposure to microplastics and nanoplastics:

• Aggravates the immune system, making us susceptible to diseases
• Throws the body’s metabolism off-balance
• Can cause cells to self-destruct at times because cells detect microplastics as a foreign agent
• May raise the risk of Parkinson’s disease
• Disrupts fetal development
• Results in harmful neurological outcomes

On top of this, we still don’t understand the full extent of harm that microplastics and nanoplastics can cause to our bodies. Therefore, as much as possible, it’s recommended to try to reduce our exposure to microplastics and nanoplastics.

What To Do Next

While the recent study is noteworthy,  the researchers left some areas for future research. Specifically, the researchers only studied the three most commonly occurring microplastics and nanoplastics and excluded less common microplastics and nanoplastics. For example, the researchers didn’t study vinyl chloride, although it was recently found to be extremely harmful.

Another important point is that boiling water doesn’t remove all microplastics. Even though boiling tap water for five minutes can remove around 84%  to 90% of microplastics and nanoplastics, it still means that we’re exposed to microplastics and nanoplastics. Our goal should be to minimize all exposure to water pollution.

at Save the Water | January 30, 2024

Fruit peel waste, a food industry byproduct, recently gained attention as a potential eco-friendly and cost-effective material for water purification. Fruit peel waste makes approximately 15 to 60% of the 25 to 57 million tons of fruit waste generated worldwide per year. Global concerns like water scarcity and pollution require innovative and sustainable solutions using similarly overlooked resources.

Water Purification Using Fruit Peel Waste

Water pollution is a growing environmental challenge. It affects both developed and developing nations. Fruit peel waste has shown remarkable adsorption potential for various water pollutants, including heavy metals, toxic dyes, and organic contaminants. Since they’re biological materials, they also act as biosorbents. They can treat polluted water in a few ways:

1. Biosorbents developed from fruit peel waste can treat pollutants from different industries like paper and pulp manufacturing, textile industries, power generation, mining operations, and much more.
2. Singaporean scientists made a water purifier out of fruit peels to be used in remote areas with limited electricity access. They used orange and banana peels to make MXene (molybdenum carbide) materials that act as solar absorbers in water desalination.
3. Citrus fruit peel wastes have been also used as natural coagulants to remove turbidity from wastewater with 75% efficiency. Moreover, these coagulants can suitably replace harmful chemical-based coagulants. A group of scientists produced activated carbon from orange peels which was used to remove harmful pharmaceuticals from water. 
4. Orange peel powder and iron oxide-hydroxide mixed orange peel powder can effectively remove lead from wastewater. These materials have been reused up to 5 times with good results.
5. Orange peel powder can also clean textile wastewater by removing harmful dyes, excessive salt content, and toxic heavy metals. Furthermore, the used peel powder was also added to cow dung to produce biogas as part of the recycling process.
6. Low-cost adsorbents like charcoal made from apple peels can remove heavy metals like copper and chromium from wastewater.
7. Dry banana and orange peel powders can effectively remove turbidity and harmful microbes from wastewater in an eco-friendly manner.
8. Several fruit peels were found to remove toxic dyes and heavy metals like iron, nickel, cobalt, and chromium from wastewater.

What Exactly are Fruit Peel Wastes?

Fruit peels are residues left after making, processing, and eating fruits. They’re extremely rich in bioactive compounds such as pectin, cellulose, polyphenols, tannins, and essential oils. However, different fruit peels have different compositions and properties. Fruit peels are generally disposed of using two methods:

1. Incineration: The burning of waste materials at high temperatures. During this process, harmful pollutants and poisonous gasses that can increase health risks are released into the atmosphere.
2. Dumping in landfills: This is the careless disposal of fruit peel waste in dumping grounds. This process releases harmful gasses like methane and carbon dioxide into the environment.

Fruit juice industries cause most fruit peel waste. These include peels from citrus fruits, watermelons, apples, bananas, pineapples, and many more. More work must be done to encourage the use of fruit peel waste as water filters rather than just disposing of them.

What Can You do?

Fruit peel waste promises to be an effective material for water purification. It offers sustainable solutions to water pollution challenges:

• You can use cost-effective, environment-friendly water purifiers and adsorbents for household purposes. 
• Corporate organizations, industries, communities, and government bodies can install filters for public use and provide funding for their large-scale production. 
• Further research and development are crucial to harness the full potential of fruit peel waste in addressing global water quality issues.

By Brigitte Rodriguez, Publishing Associate: Researcher & Writer for Save The Water | Decembe

Researchers have introduced a novel eco-friendly method for generating clean water known as solar evaporation technology. This innovative approach serves the dual purpose of purifying and desalinating water. Certainly, it stands out as a cost-effective and environmentally friendly solution to address water purification needs.

Wastewater Treatment Basics

Wastewater is water polluted by human activities. This includes domestic wastewater from private homes and businesses, as well as industrial wastewater from factories. Indeed, wastewater contains a variety of pollutants, including organic matter, nutrients, pathogens, and heavy metals.

The New Solar Wastewater Treatment Method 

The interface solar vaporization device (SVD) is based on a hybrid organic-inorganic nanocomposite (s-x-HCC). The creation of this evaporation device is based on a bilateral structure: 

1) An upper photothermal/photocatalytic layer that allows an efficient transfer of light over water. This layer is also covered by two additional types of materials: amorphous carbon and SiO2.

2) A lower layer that ensures floatability. 

This innovative structure enhances the efficiency of photocatalysis and prolongs the catalyst’s activity, leading to improved generation of clean water. The hybrid organic-inorganic nanocomposite combines the strength and rigidity of inorganic materials with the flexibility and lightness of organic materials. This groundbreaking technology holds the potential to revolutionize water desalination. Additionally, CCMs-x are materials that blend the characteristics of both organic and inorganic materials. In the case of SVD, these materials are utilized to develop devices that capture sunlight, convert it into heat, and use it to evaporate water from salt solutions.

Advantages and Challenges of SVD

There are advantages to using this type of technology:

• Low cost
• High water purification rate (97.85%)
• Contaminants in the concentrate are removed from the CCMs-x devices over a period of 60 minutes
• Better at absorbing sunlight than other materials
• Long-term durability

Meanwhile, this method also poses challenges:

• Not suitable for wastewater treatment in urban areas because of the specific properties of the water

Traditional Wastewater Treatments

There are several traditional methods for wastewater treatment. They include a set of physical, chemical, and biological processes used to remove pollutants from wastewater.

Traditional wastewater treatment methods face many challenges: 

• Increasing amount of wastewater: As more people inhabit urban areas, the production of wastewater is likely to increase proportionally.
•  New Contaminants: New contaminants are now present. This comes from new drugs and personal care products. The residue then ends up in wastewater, which is difficult to treat.
• Energy costs: Traditional treatment methods are energy intensive.  Therefore, energy costs are rising.

Other New Sustainable Methods

A number of sustainable and efficient wastewater treatment technologies are emerging: 

• Natural Treatment Systems: These systems use natural processes such as wetlands and biofilters to remove contaminants from wastewater.
• Membrane Technologies: These technologies use membranes to filter contaminants from wastewater.
• Advanced Oxidation Processes: These technologies use strong oxidants to break down organic matter and pathogens in wastewater.

Future Perspectives

The future possibilities for the SVD are vast. Specifically, it could find applications in remote or arid regions, providing a means for local communities to access clean water. Moreover, the technology holds potential for integration into wastewater treatment plants, assisting in removal of pollutants from wastewater. Additionally, the SVD could play a role in solar power plants, contributing to the generation of clean electricity.

In conclusion, the SVD has shown its effectiveness in extracting clean water from the air and purifying wastewater by removing pollutants. This positions it as a promising technology in tackling both water scarcity and pollution issues.

at Save the Water | October 10, 2023

Solar energy is being explored as a promising way of creating a sustainable freshwater supply. In theory, using solar energy in this way is cheap and effective. However, advances in this technology have been set back by performance degradation that results from salt build-up. For a long time, the dream of being able to use solar energy to produce freshwater seemed out of reach.

Climate change has caused the drying of many important freshwater sources. Thus, scientists have prioritized the search for a sustainable and effective way of creating drinking water. People may be facing a large-scale drought soon unless new solutions are found. This urgency has resulted in cross-collaboration between engineers, energy scientists, environmental researchers, and policymakers.

Using New Solar Energy Technology  

A recent article shows that the logistical problems that researchers were facing with performance decay could be reduced by using “a confined saline layer as an evaporator.” The evaporator layer works by using sunlight heat to evaporate water. Then, the vaporized water gets funneled to another section of the device. This leaves the salt behind, allowing it to be separated from the seawater and create drinking water.

This device has been shown to be highly effective. It’s said to have a high water production rate than other solar water desalination techniques that are being studied. Additionally, it has a higher salt rejection rate than those techniques.The researchers have predicted that if this device was scaled up to the size of a small suitcase, it would be able to produce four to six liters of drinking water every hour. Furthermore, it would last years before needing any replacement parts. This means that it can be sent to other countries that are at a higher risk of drought at a low cost.

This technology is promising because it can also be used in households. For example, a scaled-up device would be able to produce enough drinking water to meet the daily needs of a small family. Moreover, scientists have suggested that the technology would be very helpful for off-grid coastal communities. It would provide a way for them to access much-needed drinking water.

Why is Solar Energy Technology Important?

Water scarcity is a real threat to many communities around the world. Many regions are already struggling with the worst consequences of not having enough water to conduct their day-to-day activities:

• Economic decline due to the inability to produce crops
• Increased disease due to lack of sanitary water
• Higher rates of anxiety, stress, or depression related to water insecurity 
• Extreme food insecurity and famine
• Increased chemical contamination of water supply

Researchers predict that we’re on the verge of an imminent water crisis. The United Nations and other organizations expect that demand will outstrip supply for freshwater by 40% at the end of the decade. Due to the seriousness and urgency of the situation, many nations have prioritized this crisis. 

What Comes Next for Solar Energy ?

“For the first time, it is possible for water, produced by sunlight, to be even cheaper than tap water,” co-author Lenan Zhang, a mechanical engineer at MIT’s Device Research Laboratory, said in a statement. If the device works as predicted, it will mean that we’re one step closer to ensuring that people around the world won’t run out of freshwater supply. Although one caveat is that the device is still small for now, researchers have plans of upscaling it and making it more efficient in water production.

This device may open up doors for other innovations that will benefit humanity in the long run. It’s essential for governments globally to invest in ensuring water security for all their citizens. This push can’t be done by one nation or organization alone. Collaboration is the only way forward. The device that was developed at the Massachusetts Institute of Technology was composed of an international team, showing that diverse ideas can guide our pathway towards water security.

at Save the Water | September 09, 2023

Magnetic nanoparticles are new, non-toxic, reusable, eco-friendly materials that can remove pollutants from wastewater. The availability of pure water is crucial for a sustainable ecosystem. Our industrial and domestic activities are the primary causes of the discharge of pollutants. These include microorganisms, toxic heavy metals, and organic compounds into the water resources.

Some Basic Concepts

Nanoparticles are smaller particles whose sizes range from one to 100 nanometers. Magnetic nanoparticles are made up of specific metals, like iron, cobalt, nickel, and zinc. These metals give excellent magnetic properties. They can be separated out by using an external magnetic field. Then, they can be reused for the next treatment process. These materials are nontoxic, and their smaller size allows them to be specifically used in many different biochemical functions. They offer a highly effective means of removing various contaminants from water sources. One of the primary uses is the removal of heavy metals such as lead, cadmium, and mercury. They also help in carrying out different wastewater treatment processes such as flocculation, adsorption, filtration, photocatalysis, and many more.

How are Magnetic Nanoparticles Formed?

Magnetic nanoparticles can be produced by using three types of methods:

1. a)     Physical methods
2. b)     Chemical methods
3. c)     Biological or microbial methods

Mechanical milling is a popular physical method where different chemicals are churned in big ball mills to break down particles into smaller sizes. In contrast, sol-gel, hydrothermal, thermal decomposition methods are the renowned chemical methods. In these methods, various chemicals containing metals like iron, nickel, and cobalt undergo chemical reactions under higher temperature or pressure to form magnetic nanoparticles.

Under biological methods, either microbes, enzymes, or different parts of plants help in forming magnetic nanoparticles. For example, the fungus Corynespora cassiicola has been reported to reduce iron nitrate solution and give magnetic iron nanoparticles.

Additionally, the bacterium Geobacter sulfurreducens has been observed to form magnetic iron nanoparticles. These nanoparticles have been very efficient in removing toxic heavy metal chromium from industrial wastewater. Different wastes from agricultural industries like black tea extract, blueberries, and vineyard prunes can also produce single metal or bimetal magnetic nanoparticles.

In this report, magnetic nanoparticles were prepared by using iron or combining it with other metals. These metals included manganese, magnesium, silver, copper and zinc. The materials produced in this work proved to be 85% efficient in degrading and removing harmful pesticides from wastewater.

Apart from plant extracts, bark, and tissues, researchers have also used agricultural wastes to produce magnetic nanoparticles. Biological methods are more beneficial because they’re less toxic, cost-efficient, and environment-friendly. Furthermore, they produce higher amounts of magnetic nanoparticles with better chemical and physical properties.

Common Applications of Magnetic Nanoparticles

1. Contaminant Removal

One of the primary applications is the removal of heavy metals such as arsenic, lead, nickel, cadmium, and mercury. These nanoparticles are functionalized or bind with some other materials like silica, graphene, chitosan to form nanocomposites. Later, they can be efficiently removed from water through magnetic separation. The process involves scattering the nanocomposites into the wastewater, allowing them to bind to the contaminants, and then using an external magnetic field to separate the nanoparticles along with the attached pollutants.

2. Organic Compound Degradation

They can also play a crucial role in breaking down organic pollutants present in water. By coupling them with photocatalytic or catalytic materials, researchers have developed advanced oxidation processes that use sunlight or other forms of energy to degrade organic compounds. They can be also used as low-cost adsorbents to remove harmful chemicals. These processes are particularly effective in degrading pollutants like dyes, pharmaceuticals, and pesticides, which are often resistant to conventional treatment methods.

3.Pathogen Removal

Waterborne pathogens pose a huge threat to public health, especially in regions with poor sanitation facilities. Magnetic nanoparticles can be functionalized with other metals, antibodies, or other biomolecules that specifically target and bind to pathogens like bacteria, viruses, and parasites. Once these nanoparticles are bound to the pathogens, they can easily be removed from water using magnetic separation. Thus, this provides a viable method for disinfection.

4. Nanomaterial-Based Filters

Magnetic nanoparticles can be put into porous materials to create membranes, sponges, and coagulants for water treatment. They can selectively capture contaminants while allowing clean water to pass through. Their magnetic property eases their regeneration. This allows for their prolonged use without the need for frequent replacement.

5. Detection and Monitoring

Beyond purification, these nanoparticles can also observe water quality and detect pollutants.. Functionalized magnetic nanoparticles can act as sensors, binding to specific pollutants and creating a measurable signal. This enables real-time monitoring of water quality, helping authorities take timely action in response to contamination events. They can check for the presence of bacteria, pesticides, and harmful heavy metals in water resources.

6. Groundwater Remediation

Contaminated groundwater is a persistent environmental challenge. Magnetic nanoparticles can be fed into the subsurface to target and remove contaminants. The nanoparticles can be guided to the desired location using magnetic fields, making this approach highly targeted and effective. These nanoparticles, when immobilized with enzymes, act as biocatalysts to clean groundwater contamination.

7. Desalination

Desalination of seawater or brackish water is becoming more and more important to address the lack of freshwater in many regions. Magnetic nanoparticles can enhance desalination processes by aiding in the separation of salt ions from water. This is done through processes like forward osmosis. Additionally, they can help prevent fouling and scaling on membranes used in desalination systems. Thus, this improves their efficiency and longevity.

8. Metal Recovery

Apart from removing toxic heavy metals from wastewater, these nanoparticles can also pull out useful, expensive metals like lithium, cesium from salt water.

Challenges and Future Directions

While using magnetic nanoparticles for water purification is promising, several challenges must be addressed. These include –

• concerns about the potential toxicity of these nanoparticles
• their long-term impact on human health and environment
• the scalability of their production methods.

Researchers are actively working to ensure the safe and responsible use of these nanoparticles. Research in this field continues to evolve. Therefore, we can anticipate the development of more efficient and sustainable water purification technologies that have a lasting positive impact on global access to clean and safe drinking water.

at Save the Water | August 16, 2023

Reverse osmosis is currently used to purify water, but companies are looking to move to a more efficient approach. A number of regions are facing megadroughts that threaten water levels. It endangers population health and farming outcomes. For example, Lake Mead has provided water for millions of people for years. However, it’s now hovering near its record lowest water level. There are many such examples of water bodies being dried out. Thus, it’s paramount that we find solutions to increase water levels. 

While the world is experiencing low water level rates, a lot of wastewater is going unused. As of 2018, 80% of the nation’s wastewater is put back into water bodies without being treated. Wastewater comes from many sources such as agriculture and household water usage. It’s an untapped water source that can aid in increasing water levels.

What is Wastewater?

Wastewater is common, as it comes from our daily habits, such as bathing, flushing the toilet or doing laundry. Wastewater can also come from commercial sources, such as auto body repair shops and beauty salons. 

Wastewater contains substances that can harm human health and the environment. The majority of wastewater is just pure water. However, a tiny percentage has human waste, chemicals, soaps, and other substances that contaminate the water. 

It can be dangerous to come in contact with wastewater, as contact poses many risks: 

• Gastroenteritis (diarrhea and/ or vomiting)
• Skin and/ or eye infections
• Serious viral infections, such as hepatitis
• Giardiasis and cryptosporidiosis, which involves severe stomach cramps 

Reverse Osmosis Filtration

Currently, most companies use reverse osmosis for water purification. It is the most cost-effective, energy-efficient technology available. Conventional reverse osmosis is able to turn seawater and groundwater into freshwater. However, this method can’t purify super-salty waters, which contain up to double the amount of salt content of the ocean.

The need for super-salty water purification may not be clear, as it exists in lesser amounts than the other sources. Yet, this water now makes up a growing percentage of water bodies. This is because freshwater is becoming saltier due to road de-icing and other industrial activities. This increased saltiness threatens the wellbeing of people and wildlife. Thus, it’s increasingly important to find methods to purify it into drinking water.

In a recent study published in Desalination, researchers from the National Alliance for Water Innovation (NAWI) analyzed a novel form of reverse osmosis named low-salt-rejection reverse osmosis. In theory, this new system is able to treat very salty water. Nevertheless, it’s important to remember that this method is still theoretical.

Low-Salt-Rejection Reverse Osmosis 

The researchers from the Desalination article used supercomputers to analyze thousands of system designs. They studied the costs of water purification, water production, and the energy it takes for that method. A mathematical model was employed for quick assessment of these different methods. The results showed that low-salt removal rate reverse osmosis is mathematically the most cost-effective method. The model not only reduced the total costs but also increased the supply production by up to 63%.

The reason why this method was found to be the most cost-effective is that the low-salt-rejection reverse osmosis systems allow for more salt to pass through the membrane. This means that it requires less force which, in turn, means that it’s using less energy to push the water through the membrane. 

Although more salt infiltration is happening, the result is water that’s still too salty to drink. Therefore, the water that’s still salty is returned to the membrane stage to make it drinkable. Once the salt content has dropped enough, water purification companies employ reverse osmosis membrane, which is the method currently used for most water purification, to produce drinkable water.

How Low-Salt-Rejection Reverse Osmosis can Help us in the Future

Low-salt-rejection reverse osmosis seems to be a cost-effective and highly efficient process. Thus, it could prove to be influential in how we treat water. Freshwater scarcity is becoming a bigger issue globally. Hence, it’s crucial  that we find ways to raise access to freshwater by increasing the supply we have available.

By improving the energetic and economic performance of water purification, we’re taking a step in the right direction. Although the method is currently based only in theory, it’s likely that it can come to practical fruition sometime in the near future.

at Save the Water | July 28, 2023

“Forever Chemicals,” or PFAS—per- and polyfluoroalkyl substances—chemicals, were found in nearly half of US faucets, according to a study conducted by the United States Geological Survey (USGS). This federal study is considered one of the most comprehensive of its kind. Specifically, it shows the risks of exposure to forever chemicals in the drinking water supply of many citizens. These chemicals pose special risks due to the array of items they show up in, such as nonstick pans and food packaging.

There were no policy suggestions in the report because of the agency’s status as a scientific research agency. However, the study shares important information that can be used to better understand the risk of exposure to these chemicals. Furthermore, it can aid in making decisions about the need to test or treat drinking water supplies.

What are Forever Chemicals?

Forever chemicals are a class of chemicals often added to products to make them grease proof, waterproof, stick-proof, or stain-resistant. They’re found in many items that people use daily , which makes them especially dangerous. These include carpets, umbrellas, medical equipment and masks, and numerous other products.

The term “forever chemicals” refers to the fact that they often resist breakdown in the environment and in our bodies. As a result, not only are they widespread but they also may take decades to start breaking down. Manufacturers aren’t mandated to disclose to consumers that they are using forever chemical. Therefore, it is difficult to fully grasp the extent to which these chemicals enter our lives. The United States Environmental Protection Agency (EPA) doesn’t have any regulations and doesn’t test for most forever chemicals. For this reason, they could be more widespread than we think.

Although the study focused on drinking contaminated water, there are several ways exposure to forever chemicals can occur:

• Eating fish that come from water contaminated with these chemicals
• Swallowing soil or dust
• Eating food grown in places that use these chemicals
• Eating packaged foods
• Using consumer products that are resistant to staining, water, or grease

How are Forever Chemicals Harmful?

Studies have shown a link between forever chemicals and a number of health issues. In June 2022, such studies led the EPA to issue health advisories that warn that the chemicals are much more harmful to human health than researchers had initially thought. Additionally, they are likely harmful at levels thousands of times lower than scientists previously thought.

The health problems caused by chemicals affect both young and old people and are broad in range. Some of the health issues linked to forever chemicals include:

• Cancers, especially kidney and testicular
• High cholesterol 
• Thyroid disease
• Liver damage
• Asthma and allergies
• Reduced vaccine response in children

Other studies have shown that forever chemicals can result in decreased fertility, newborn deaths, delayed development, birth defects, and low birthweight. These health issues are of major concern due to the ability of forever chemicals to last for generations. In fact, if we were to stop manufacturing such chemicals starting tomorrow, there would be huge amounts left in the environment to cause potential harm to people’s health.

What Does This Study Change?

The USGS study showed that the majority of exposure was found near urban areas and other potential sources of forever chemicals. This included major US sites such as the Great Lakes, Eastern Seaboard, and Central/Southern California regions. This study backs up previous research that showed that people who live in urban areas have a higher risk of exposure to these chemicals. The study’s report says that the odds of forever chemicals not being observed in tap water is about 75% in rural areas. However, this number dropped to 25% when they looked at urban areas. Consequently, environmental agencies will be able to better understand the spread of these chemicals and the risks of exposure due to location. 

The Environmental Working Group advises the use of filters that contain activated carbon or reverse osmosis membranes in homes. This can remove the unsafe compounds from water sources.

at Save the Water | March 04, 2023

Pure and clean drinking water is our basic right. Poor and outdated wastewater management technologies are one of the big hurdles on this road. Thermal hydrolysis of sewage sludge is an upgraded technology to treat wastewater. Upmanu Lall, director of the Columbia Water Center has also stated that it’s high time to improve wastewater treatment technologies to secure safer drinking water for coming generations.

Thermal Hydrolysis

Thermal hydrolysis uses steam to treat sewage sludge or wet organic wastes present in wastewater. It’s used prior to anaerobic digestion in wastewater treatment plants. This process requires high temperatures  of around 140 to 170 °C and pressure of about six to nine bars.

During this process, steam releases energy at a high pressure. This increases the reactivity of water and destroys the chemical bonds of the sewage sludge. Post wastewater treatment, people use sewage sludge as bio-compost to enrich soil nutrients. Thus, it’s very important to treat sewage sludge appropriately.

Sewage Sludge

Wastewater treatment plants treat wastewater from sewage systems, and solid wastes are separated from liquid wastes. These solid wastes form sewage sludge, which can then be further treated or processed by thermal hydrolysis. Sewage sludge has two types: primary sludge and secondary–or waste-activated–sludge. Primary sludge has higher fibrous and lipid content, but less phosphorus and protein content. In contrast, secondary sludge contains more organic matter such as carbohydrates, proteins, microbial cells, etc.

After thermal hydrolysis, anaerobic digestion of the sewage sludge takes place, where bacteria breaks it down. Sewage sludge may contain dangerous chemicals and metals leached from industrial, household, municipal, and medical wastes. It also contains non-biodegradable organic matter.

Steps of Thermal Hydrolysis

Thermal hydrolysis is carried out in a batch process. The apparatus consists of a pulper, reactor, and flash tank. The process follows three steps:

1. The sewage sludge is constantly fed into the pulper and preheated at about 100 ℃.
2. From the pulper, the warm sludge goes to the reactor. In each system, there are about two to five reactors placed. Once the reactor gets full, it’s sealed. Steam is flushed inside, and the temperature of the reactor increases up to 180 ℃ at a pressure of about seven bars. The sludge is treated here for about half an hour to kill bacteria and other pathogens.
3. Afterwards, sterilized sludge is fed into the flash tank at an atmospheric temperature. This abrupt reduction in pressure damages the cells of organic material. When the pressure drops suddenly, steam is produced and is again flushed to the pulper, which is then reused there.

The treated warm sewage sludge is then cooled to room temperature using heat exchangers. Lastly, it’s fed to digesters for the next process of anaerobic digestion.

Advantages of Thermal Hydrolysis

Thermal hydrolysis has multiple benefits:

• It reduces pathogens, antibiotic-resistant bacteria, and organic micro-pollutants in wastewater.
•  It enhances water quality.
• After thermal hydrolysis, the biodegradability of organic contaminants also increases.
• It helps increase the production of biogas during wastewater treatment by up to 75%.
• This technology decreases the duration and increases the efficiency of the anaerobic digestion process, which is a very important stage of wastewater treatment technology.
• It helps reduce water quantity from sewage sludge. Hence, it becomes easier to treat sludge in advanced stages of wastewater treatment.

Drawbacks of Thermal Hydrolysis

Thermal hydrolysis consumes a lot of energy. It takes place in the absence of oxygen gas and other oxidants. Therefore, after treatment, the color of the sludge darkens. This dark-colored sludge can reduce the efficiency of later steps of wastewater treatment. For example, it can hinder the Ultraviolet disinfection process. To overcome these challenges, thermal hydrolysis can be replaced with an advanced thermal hydrolysis process. This process involves the use of oxidants.

What Can You Do?

CambiTM has installed more than 70 thermal hydrolysis plants in various countries, such as the United States, United Kingdom, and China. This, in combination with anaerobic digestion systems, provides a huge benefit to the masses. You can also help manage wastewater:

• Cut down the incautious disposal of your household wastes which further collects as sewage sludge.
• Reduce sewage sludge by making your septic tanks and drainage system leak-proof, as well as taking care of their maintenance regularly.
• Run social awareness programs to pass on this information.
• Involve the government to take charge of maintaining sewage and drainage systems.

at Save the Water | January 30, 2023

Increasing city culture, industries, use of electronic equipment, and many more processes have introduced heavy metal ions like lead, arsenic, iron, cadmium, nickel into our lives, surroundings, and as well as in our water bodies. Such heavy metal ions can cause different deadly diseases like cancer, cardiovascular and neurological disorders, kidney failure, hypertension, and miscarriages. Nowadays, microorganisms based bio sorbents are being used for removing heavy metal ions from wastewater.

What Are Bio Sorbents?

Basically, bio sorbents are biological materials that are used to remove pollutants from water. They remove pollutants through a chemical and physical process by which one substance attaches to another called sorption. Microorganisms like cells of algae, fungi, yeast, and bacteria are chief bio sorbents for wastewater treatment. However, some seaweeds, fruit peels, industrial and agricultural wastes like coffee husk, and pine waste are other examples of bio sorbents. They are chiefly used to remove toxic dyes and heavy metal ions from wastewater.

How Can Microorganisms Based Bio Sorbents Be Made?

Microorganisms (Aspergillus niger, Saccharomyces cerevisiae) are isolated and cultured in laboratory conditions. Thereafter, the microorganisms are filtered, washed, dried, and ground to form powder. Afterwards, this powder is stored in an air-tight container until its use in metal ions removal from wastewater. Additionally, the surface of bio sorbents powder is treated with specific chemicals like hydrogen peroxide to enhance their sorption capacities.

How Do Bio Sorbents Work?

Biosorption is a physicochemical process which takes place on the surface of bio sorbents. Some active groups like carboxyl, amino, hydroxyl, and sulfate on the surface of the bio sorbents interact with the heavy metal ions. The heavy metal ions bind with these active groups and get removed from wastewater. Overall efficiency of this process depends on several factors. Here are a few:

• the types of heavy metal ions
• the structure of bio sorbent
• pH
• temperature
• quantity and size of bio sorbents used
• contact time between wastewater and bio sorbents
• quantity or concentration of metal ions in wastewater

Microorganisms secrete some enzymes which destroy dye molecules present in wastewater and help in their complete removal.

Benefits of Microorganisms Based Bio Sorbents

The microorganisms based bio sorbents offer many advantages in wastewater treatment:

1. Such bio sorbents are very cheap as the cost of preparing and operating bio sorbents is very low.
2. These materials can easily bond metal ions, so their absorption capacity is very high.
3. They are easy and safe to use in treating wastewater even at larger scales.
4. They are eco-friendly, non-toxic, and compatible for use in our ecosystem.
5. We can reuse these bio sorbents many times.

Experiments Paving The Way in Lab

Scientists have conducted various experiments to develop microorganisms based bio sorbents for removing heavy metal ions from wastewater efficiently.

1. A group of environmentalists cultivate bio sorbents from baker’s yeast or Saccharomyces cerevisiae and use them to remove lead, cadmium, and nickel from wastewater samples within 25 minutes at room temperature. These bio sorbents remain stable up to 8 months and could be recycled many times with almost 90% efficiency.
2. In Egypt, scientists dried a fungus Aspergillus niger to make a bio sorbent for removing iron ions from wastewater within an hour. This bio sorbent could also be recycled and reused a number of times.
3. In Romania, yeast cells of the beer industry, Saccharomyces pastorianus were used for a study. In this study, these yeast cells were bonded with natural biopolymer, sodium alginate for removing a toxic dye, methylene blue from water samples.
4. Further, many agricultural wastes like groundnut and coconut shells, banana and orange peels, used coffee and tea, and many more materials were also found as potential bio sorbents in the removal of lead ions from wastewater samples.

Future Perspectives

Along with the ongoing research, researchers and the public certainly can do a lot more in the field of microorganisms based bio sorbents for removing heavy metal ions from water bodies. 

1. We should not dispose of our toxic wastes containing heavy metal in water bodies without any further treatment.
2. We should promote the use of microorganisms based bio sorbents for wastewater treatment at large scale.
3. The techniques used for treating or modifying microorganisms should be improved.
4. More in-depth research is desirable for a promising utilization of these bio sorbents, so that they could compete with commercial adsorbents in the treatment of wastewater.
5. A dynamic study would be necessary before a sustainable transition of such bio sorbents to real conditions.

at Save the Water | October 19, 2022.

SODIS is a World Health Organization (WHO)-approved, cheap, old-school process commonly used for domestic water treatment. It does not change the taste of water. The USA is one of the top countries in the world publishing research in this growing area of interest.

More About SODIS

SODIS is basically an environment-dependent, repeatable process. We can start it at our home by using ordinary plastic bottles or containers. It is mainly used in areas where sunlight is abundant. Ultraviolet (UV) rays of sunlight can effectively kill viruses and microorganisms like E. coli present in contaminated water which are even resistant to chlorination. These rays inactivate and damage cells of microorganisms, thus, preventing them from multiplying further. Additionally, such microorganisms cause various water-borne diseases like typhoid, dysentery, fever, intestinal infection, and many more. Water is treated and stored in the same container, hence it is an overall cheap, less time-consuming, space-occupying technique with fewer chances of recontamination.

How Does it Work?

SODIS works by using UV-A and infrared (IR) radiations of sunlight altogether. Initially, UV-A radiations damage living cells of microorganisms. After that, when temperature of water rises to 70-75 °C, IR rays help in thermal disinfection, or pasteurization of water. Therefore, the overall efficiency of the process increases. Since microorganisms are extremely sensitive to heat, they do not survive in these specific conditions.

This method appeared to be better at killing microorganisms in water, when compared with other traditional water treatment techniques like chlorination, filtration, ozonation, electroflocculation, advanced oxidation, and others. Besides, it does not produce harmful by-products and certainly is way cheaper.

Time Taken by SODIS

Sunny days- 6 hours.

Cloudy days- 48 hours.

Not favorable during rainy days.

If the turbidity of contaminated water is high, then the period of SODIS treatment extends.

Some Real-world Examples

1.       Lexington, KY, USA: Environmental Research Training Laboratory (ERTL) at the University of Kentucky conducted some experiments to study the feasibility of SODIS in removing E. coli from turbid water at temperature less than 50 °C. When the turbidity of water was increased from 30 to 200 Nephelometric Turbidity Unit (NTU), the efficiency of SODIS in killing microorganisms decreased accordingly.
2.       Ecuador and Bolivia: Jonathan Spear & Valerie Grosscup, The Colorado College, USA, helped about 35 communities and more than 3,500 people on the northern coast of Ecuador with their seven-week SODIS project. Engineers Without Borders (EWB)-USA has run the SODIS project to improve water quality in rural communities of Bolivia. Missouri University of Science and Technology conducted SODIS experiments, under sunny and cloudy weather conditions. Later, it was concluded that on sunny days, E. coli were completely removed from water while on cloudy days, only 50% were removed efficiently.

 Advantages of SODIS

• SODIS not only improves the microbiological quality of drinking water but also reduces cases of waterborne diseases, thereby supporting human health.
• It is affordable, simple, and replicable technique because it depends on sunlight, a renewable source of energy.
• The use of traditional heating sources like coal, fuel, and wood is not involved, thus reducing environmental pollution.
• The chance of recontamination is low if purified water is consumed within 24 hours.
• It does not require huge machinery or costly infrastructure, and it can be started at home with plastic bottles.

Limitations of SODIS

• SODIS requires sufficient sunlight. For that reason, its use chiefly depends on the weather and climatic conditions.
• It cannot be used for very dirty, turbid water.
• It is not useful for treating large volumes of water.
• In unfavorable weather conditions, SODIS requires more time to treat water.
• Plastic containers used in the SODIS technique get contaminated, causing leaching of harmful elements and associated health problems, if used for long  periods.
• It cannot treat non-biological impurities in water.

Solutions to the Problems

• To avoid the harmful effect of plastic bottles, alternative materials could be containers made of glass, polypropylene, polycarbonate, polyethylene, and others. 
• Carbonates and bicarbonates dissolved in water absorb UV radiations and do not disturb the process.
• Use of mirrors, solar collectors concentrate solar radiations, consequently process efficiency increases significantly. 
• The bottom part of SODIS containers can be painted black, so that higher temperatures can be maintained inside. 
• Integration of photocatalysts, pretreatment of water (use of natural coagulants and adsorbents), and the use of continuous flow-based systems can enhance the efficiency of SODIS.

What Can You Do to Support SODIS?

SODIS is indeed getting more popular, as the amount of research on it has been increasing every year. These studies suggest that SODIS can be used worldwide to treat water irrespective of weather conditions, as it worked well even in the colder climate of Finland. This cheap, low-tech process can also treat harvested rainwater in poor regions. With this in mind, more investigations are required to estimate all the design and control parameters for SODIS treatment of water. Not to mention, we can break social barriers to this technique by publicizing this practice even more at the community level.

By Samhar Almomani, Publishing Associate Researcher & Writer at Save the Water | September 15, 2022

In late August, Missippi’s Governor declared a water emergency for the residents of Jackson, Mississippi. Pumps at the main water treatment facility failed, leaving more than 150,000 residents without a reliable water source. To many onlookers, what the residents of Mississippi are going through echoes a similar crisis that afflicted Flint, Michigan in 2016. 

These crises remind us need to invest in modern, safe water infrastructure.

Dangers of Underfunded Water Infrastructure

Many dangers result from underfunded water infrastructure:

• Increased breakage that results in cutting off water supply
• Lead and copper leaching from corrosion that makes water dangerous
• More water boiling notices due to contaminants 
• Increased leaks leading to high financial costs

The City of Jackson in Mississippi suffers from many of these problems. Recent torrential rains compounded years of water infrastructure neglect. Now, thousands of residents have little to no access to clean water. The main water treatment facility failed and directly caused this situation. In 2020, the treatment facility failed an Environmental Protection Agency (EPA) inspection.

The EPA had said that the water in the treatment facility could become toxic by being the host to harmful bacteria and parasites “based on observations of the water’s turbidity, or cloudiness, as well as ‘disinfection treatment concerns, and/or the condition of the distribution system.”

The Health Effects of Contaminated Water

Water contamination can cause disease in millions of people that rely on that water supply. Ideally, water would be supplied from local water sources, such as rivers and streams. 

However, that is not always the case.  Years of underfunding and neglecting water infrastructure exposes people to toxic water every day. Specifically, water treatment facilities that are supposed to clean out the water are not maintained properly, leading to a toxic water supply being sent to homes, schools, and hospitals. Usually, people from a disadvantaged background bear the worst effects.

People from disadvantaged backgrounds also are located in places that are often in low-lying flood zones, near industrial facilities, and other areas considered prone to natural disasters. Living in these areas makes a person especially vulnerable to dangerous effects to health. Namely, failing infrastructure after natural disasters will lead to hazardous substances in the water facilities.

What Can You Do to Fix Underfunded Water Infrastructure?

EPA recommends two ways to tackle  underfunded, aging water infrastructure. The first one involves a wastewater treatment clearinghouse, which is a platform that allows the sharing of the latest and most cost-effective solutions relating to water treatment. Notably, the clearinghouse will include information for both centralized and decentralized treatment systems.

The other EPA recommendation involves an Alternative Technologies and Assessment chart. This chart includes resources that point to the best, newest, and most innovative technologies relating to water infrastructure. 

You can educate yourself about these solutions by clicking the links above. By educating yourself about the ways you can help, you can become an avid activist for safe, drinkable water. This could be done through a number of ways, such as attending council meetings or voicing your concerns.

By bringing attention to the dire issue of underfunded, old water infrastructure and looking into ways you can help, you can start helpful changes in both your community and the world.

Microplastics have become a household topic in the last few years. They are a physical pollutant that’s very worrying. Plastic contains chemicals that can endanger humans. Microplastics are also small and hard to notice. This poses a risk to the health of people and the earth.

We make and use a lot of plastic, so microplastics are more and more common. Many scientists continue to work to find how to solve this problem.

What Are Microplastics?

Microplastics are very small pieces of plastic. They are less than 5 millimeters in diameter. They break off of larger plastic items in the water or on land. Some synthetic materials, like certain clothing types, also contain microplastics. We can find these small pieces in all kinds of environments.

Here are just a few places where microplastics have been found:

• Water systems
• The human placenta
• Farm soil
• Air in remote areas
• The Arctic Ocean

Microplastics in the environment put us at risk. They can kill the plants and animals they share soil or water with. We rely on some of these creatures for food. Even scarier, microplastics can make it into our bloodstream.

Recent research also revealed that they can carry disease through water systems. After traveling through the water, these diseases affect both wildlife and humans.

The best solution is to stop polluting water with plastic and other contaminants. However, that is next to impossible. Water pollution comes from both industries and individuals.

Humans have done a lot of damage already. We should work hard to prevent more water pollution. In addition, we should also solve the current problem. Luckily, researchers are finding ways to do so.

Plastic-Eating Enzyme

Plastic and microplastics both pollute the environment. It takes hundreds of years for plastic to break down naturally. To speed up the process, engineers created an enzyme. This enzyme breaks down plastic in just days.

Enzymes are very small, but they help chemical reactions happen in all living beings. In other words, they take apart old things and make new ones.

However, it’s hard for plastic-eating enzymes to exist outside of a lab. Researchers need to find out how to make this technology stronger. Then, these plastic-eating enzymes can be used in all environments.

Tiny Robots Eat Microplastics

Microplastics are tricky because they are small and hard to notice. Some researchers created a different solution: tiny, plastic-eating robots. They’re also called microrobots.

Microrobots are coated with a material that attracts microplastics like a magnet. When the plastic is detected, the robots break down the material that bonds it together. In other words, the microplastics become natural materials.

So far, these microrobots can only be used in water. Even then, they do best in closed water systems, like drinking water and wastewater plants. Unfortunately, the magnetic material can attract other things, too. Other water pollutants like oil, waste, and non-plastic trash disrupt the microrobots’ functioning.

Still, these robots merit continual study. They could be a big help in filtering microplastics out of our local water systems.

Nanoparticle Coated Sponge

We all know sponges soak up water and soap to wash our dishes. However, scientists found that sponges can also be used to soak up microplastics.

First, the sponges are coated with nanoparticles. The nanoparticles act like a glue that only sticks to plastic. Then, the particles attract microplastics. The sponge soaks them up to be removed from the water.

Once scientists improve this technology, it could be used on both small and large scales. This means you could have a nanoparticle-coated sponge at home. Imagine if every person played a part in preventing water pollution. It would make it more efficient for large-scale filtration later.

Looking Forward

These are just some of the promising new technologies. Researchers are also exploring alternatives to plastic. Furthermore, traditional filtration methods continue to improve as our understanding of microplastics grows.

By Matthew Taylor, Associate Researcher & Writer for Save The Water | November 30, 2021

When you think of contaminants in water, things like arsenic, lead, or E. coli probably come to mind. Yet, did you know that radioactive contaminants such as uranium and radium are also commonly found in water? In many cases, water that you drink every day has radioactive materials in trace amounts, or low levels, that are harmless. However, higher levels of radioactive contaminants in water can be harmful or even fatal.

What are radioactive materials?

Radioactive materials emit ionizing radiation. This is a kind of energy that removes electrons from atoms found in the air and in water. It can also break down molecules in the human body. Low levels of ionizing radiation come from natural sources, including space and the Earth itself. At higher exposure levels, however, it can be detrimental. Furthermore, people can get exposed to unnatural sources of radiation in several ways. This includes certain building materials, diagnostic medical exams, and contaminated water due to leaching.

Why are radioactive materials problematic?

Radioactive materials are harmful to living organisms and the environment.

In people, the radiation emitted by these materials can cause severe health problems. One of the most significant consequences is an increased risk of cancer. Other potential health problems include toxic kidney effects, blood diseases, tuberculosis, cardiovascular problems, and respiratory disease.

Moreover, radiation can stunt plant growth, mutate animals, and make soil infertile. For example, animals that drink from bodies of water containing radioactive materials can become sick. As contaminated water leaches into the soil, it can make it hard for plants to grow. Radiation can also spread through groundwater supplies, further toxifying the surrounding environment.

How can you remove radioactive materials from water?

Radioactive materials can be difficult to remove from water. For example, you cannot simply boil water to remove radioactive materials from the water. Nor can you remove them with many convenient home water filters like the kind that might be on a pitcher in your fridge. Some can, but finding the right one requires an informed purchase from the consumer. Luckily, it isn’t impossible to remove dangerous radioactive materials from the water you use and drink. There are a few commercially available technologies available for this purpose.

Reverse osmosis

Reverse osmosis is one of the most effective ways to remove radioactive materials from water. Pressure forces water through a membrane with very tiny pores. These pores allow water molecules through. These pores are so small that many molecules and even larger atoms cannot get across. As a result, the membrane catches radioactive particles. Reverse osmosis membranes can remove up to 99% of radioactive elements such as uranium and radium from water. This makes reverse osmosis highly effective for the treatment of radioactive water.

Ion exchange

Ion exchange is another effective method of removing radioactive materials from water. Water passes through a resin that contains exchangeable ions. These stronger bonding ions are exchanged with the weaker radioactive materials in the water. Thus, the radioactive materials stay in the resin. Radium, which is a cation (a positively charged ion), is exchanged for other cations like potassium or sodium. Uranium, which is an anion (a negatively charged ion) is exchanged for other anions like chloride.

Carbon filtration

Carbon filtration is also effective at removing radioactive materials from water. Water passes through a filter made of activated carbon. In doing so, the carbon absorbs and fixes radioactive contaminants in the water. Active carbon is inexpensive. The cost makes this method of radioactive water treatment readily available. Eventually, the activated carbon must be replaced once its load capacity is reached. At this stage, it loses its ability to absorb contaminants. 

Any one of these technologies is effective at removing radioactive contaminants from water. You can never remove 100% of radioactive contaminants from water. You can, however, remove more of them if you combine the use of these technologies. For example, you could pass water through a carbon filter. You could then follow it with a reverse osmosis membrane. Doing so would be more effective than using either of these technologies on their own.

Bottom line

Radioactive contaminants in water are a serious problem for people, animals, and the environment. They can make people sick, make the soil inhospitable to plants, and cause mutations in animals. Radioactive contaminants can be difficult to remove from water. There are a few commercially available treatment options available that are effective, including reverse osmosis, ion exchange, and carbon filtration. Combining multiple treatment technologies is more effective at removing radioactive contaminants from water than using one technology by itself.

If you want to learn more about contaminant removal from water, be sure to check out the Save the Water^TM website!

By Matthew Taylor, Associate Researcher & Writer for Save The Water | October 24, 2021

Did you know that there are other ways to treat water besides using traditional systems such as filters or treatment plants? A good example of an alternative to these approaches, which are active water treatment systems, are passive water treatment systems. These technologies are lesser-known but can be equally as effective and interesting. 

What is passive water treatment?

Passive water treatment systems do not require regular human intervention to operate. They rely more heavily on natural chemical, biological, and biogeochemical processes to treat water. This is in contrast to active water systems, such as an in situ chemical injection program or a water treatment plant. Both of these options require consistent human maintenance and upkeep.

One example of when a passive water treatment system may be used is when a mining operation is closing down. A passive system is preferable in this situation to treat the mine’s water as there is little-to-no human presence around the site as mining activities are coming to an end. Also, this water must be treated for years after the mine officially closes while workers are long gone. 

What are some examples of passive treatment systems?

There are many kinds of passive treatment systems, including:

• Limestone diversion wells: The main purpose of a limestone diversion well is to naturally reduce the acidity of water by using limestone as a neutralizing agent. This process begins with groundwater flowing through a pipe into a well or pit filled with crushed limestone. After the limestone treats the water, the water overflows the well. This system is less passive than other options mentioned in this article as the limestone in the well eventually needs replacement.

• Limestone drains: There are two kinds of limestone drains: oxic and anoxic. Both consist of a bed of crushed limestone that reduces the acidity of the water upon contact. The difference between these two types of drains is that the water in an oxic limestone drain is exposed to the atmosphere. In an oxic limestone drain, metals in the water oxidize because of the atmospheric exposure. The limestone loses its effectiveness because the resulting metal precipitates cover it. In an anoxic limestone drain, there is no contact between the water and atmospheric oxygen. Metals do not oxidize and metal precipitates do not cover the limestone.

• Wetlands: The ecosystem of a wetland is able to naturally treat water thanks to its soil, plants, and microbes. These elements work together to remove contaminants. Soil acts as a filter to capture contaminants. It also acts as a home for bacteria that can consume and break them down. The bacteria release water and gases like carbon dioxide as a result. The roots of plants also serve as a home for this bacteria to grow on, and can also absorb nutrients in the water. In places where a wetland does not naturally exist, artificial wetlands are sometimes developed to mimic these benefits. There are two kinds of constructed wetlands: 
  • In subsurface flow wetlands, water flows through a bed of porous material such as gravel. This bed sits on top of the soil and sediment at the bottom of the wetland. 
  • In surface flow wetlands, there is no bed of porous material. Water flows over the soil and sediment at the bottom of the wetland. 

The water in a subsurface flow wetland does not come into contact with atmospheric oxygen. Similar to an anoxic limestone drain, metals do not oxidize and metal precipitates do not cover the bottom of the wetland. The water in a surface flow wetland, meanwhile, does come in contact with atmospheric oxygen. Overall, this means that a surface flow wetland loses its effectiveness more quickly than a subsurface flow wetland.

• Permeable reactive barriers: Permeable reactive barriers are underground walls constructed of a reactive material, like limestone or iron, which treat groundwater. As groundwater flows through this barrier, it works to trap contaminants found in the water in several ways: 
  • Contaminants may stick onto the particles of the barrier’s material in a process known as sorption. 
  • Contaminants may react with the barrier material to produce less dangerous contaminants. 
  • Microbes in the barrier may consume and biodegrade some of the contaminants. 
  • Dissolved metals in the water may settle out and become stuck in the barrier. 

Since it is clear that there are many types of passive systems to choose from, how do developers choose the right one to build? A number of factors, including budget, location, availability of resources, and the chemistry of the water are all taken into account before making the final decision.

Why choose a passive system to treat water over an active system?

The main advantage of a passive system is that it does not need constant maintenance or upkeep to operate. A passive system can run on its own with infrequent checks by maintenance crews to make sure that it is operating as it should.

Also, passive treatment systems are usually less obvious to the untrained eye than active treatment systems. They look more aesthetically pleasing and natural. An active treatment system like a water treatment plant may be an industrial eyesore. A passive treatment system like a permeable reactive barrier or constructed wetland can fly under the radar to the casual observer.

Lastly, passive systems do not require constant maintenance or intervention. They also have far lower operating and capital costs than many active treatment systems. Lower costs are a major benefit to developers and owners.

Why not choose a passive system to treat water over an active system?

Despite the many advantages of passive treatment systems, they are not always favorable over active treatment systems. For example, while infrequent maintenance and intervention can be advantageous for many reasons, it can come with downsides as well. For example, a lack of regular interaction with a passive treatment system can potentially lead to inconsistent tracking of water quality. 

Also, passive treatment systems are newer inventions. They aren’t always as well-known or well-understood as active treatment systems by water treatment experts. This could potentially lead to gaps in knowledge and uncertainties when dealing with these technologies. 

Finally, passive treatment systems may require much more space than active treatment systems to build. A constructed wetland, for example, may need many available acres to develop. A chemical injection site, meanwhile, would require less land.

The bottom line

It is clear that passive treatment systems serve as viable, low-maintenance alternatives to active treatment systems. While no water treatment system can last indefinitely without human intervention, passive treatment systems require minimal upkeep to treat water and can last for many years.

Another benefit we can take advantage of is that there are several kinds of passive treatment systems available that can treat surface water and groundwater. With each having its own treatment process and ability to treat different contaminants, it’s great that we have more than just one choice. 

If you want to learn more about different water treatment technologies, take a look at articles like this one and others on the Save the Water^TM website!

By Matthew Taylor, Associate Researcher & Writer for Save The Water | September 27, 2021

When you think of water treatment, you probably think of water treatment plants in your area or filtration systems for drinking water. But did you know that wetlands can also treat water? In fact, artificial wetlands, known as constructed wetlands, are built to replicate the water treatment abilities of natural wetlands.

What is a constructed wetland?

As the name implies, a constructed wetland is artificial—that is, a wetland that is not natural but which human hands have built.

There are two kinds of constructed wetlands—surface flow wetlands and subsurface flow wetlands. In surface flow wetlands, water flows over the soil and sediment at the bottom of the wetland. In subsurface flow wetlands, water flows through a porous substrate such as gravel or sand above the soil and sediment at the bottom of a wetland. Water in a surface flow wetland is exposed to the atmosphere, while water in a subsurface flow wetland is not.

Surface flow wetland (no endorsement)

Subsurface flow wetland (no endorsement)

How do constructed wetlands treat water?

Constructed wetlands have three features that remove contaminants from water: vegetation, soil, and microbes. These features work together to significantly reduce the concentrations of contaminants in the water, including arsenic, lead, and zinc.

Plants in a constructed wetland absorb some nutrients such as phosphorus and nitrogen through their roots, although that is not their most important role in the process. Their roots provide surfaces for bacteria to grow on, which help to remove contaminants from the water. The plants also produce oxygen which, once dissolved in the water, bacteria use to remove some of the contaminants from the water.

Soil acts as a natural filter. When water passes over and through it, soil captures some of the water’s contaminants. Soil also contains bacteria and other microbes which help to break down contaminants, thus cleaning the water.

Microbes can help remove contaminants from water as well. For example, during the process of nitrification, microbes oxidize ammonia to nitrite, then nitrate. Because of the many kinds of microbes and microbial processes, microbes can play a large part in removing different kinds of contaminants from water.

Why would you use a constructed wetland to treat water?

One of the biggest advantages of constructed wetlands over other water treatment methods is how little maintenance they require. Unlike more active water treatment methods (like water treatment plants), constructed wetlands do not need to be constantly maintained. Once their plants have matured, these ecosystems are pretty low-maintenance, although there is still some maintenance work to do. Inflows to and outflows from the wetlands must remain clear to allow water to flow through the wetlands. Certain animals and plants can limit the treatment efficiency of the wetlands, so they must go.

Constructed wetlands are also an aesthetically pleasing, cost-effective alternative to other water treatment solutions. Rather than having to build an eyesore, a constructed wetland can tie into a natural environment with little difficulty. The major materials needed to build a constructed wetland are water, plants, and soil—all of which are renewable resources. Wildlife might even come to the wetlands, making them even more pleasing.

A traditional water treatment plant is much less pleasing to the eye than a constructed wetland (no endorsement)

Constructed wetlands do have their limitations. Plants die in the winter, and water freezes over. That means that in colder areas, constructed wetlands work best for seasonal water treatment needs. Constructed wetlands also have a large footprint due to their size, meaning that a constructed wetland is not the most effective water treatment option in areas where there is minimal space.

Where are constructed wetlands used to treat water?

Constructed wetlands can be used to treat many kinds of water, including agricultural wastewater, industrial water from industries (like the petroleum and pulp and paper industries), municipal wastewater, stormwater runoff, landfill leachate, and mining water.

Constructed wetlands are especially useful for treating mining water because of the different kinds of contaminants that mining processes produce. Different mines produce different contaminants. For example, a gold mine might produce different contaminants than a copper mine. Constructed wetlands can take care of many of these contaminants at once.

At the Minto Mine, a copper mine in Yukon Territory, Canada, a constructed wetland significantly reduced contaminant concentrations in the water, including copper, by nearly 100%.

Another successful example is the wetland used to treat municipal wastewater in Emmitsburg, Maryland. Over two years, the cattails in the wetland removed 84% of suspended solids in the water. It cost around $89,000 to design and install this wetland. A conventional wastewater treatment system, meanwhile, might cost anywhere from $200,000 to upwards of $1 million.

Projects like those mentioned above are clearly viable and affordable. They are not just a pipe dream. You could lobby your local government officials to consider a constructed wetland as their next water treatment project rather than installing a more active system like a water treatment plant.  

Bottom line

Constructed wetlands are a low-cost, low-maintenance alternative to other kinds of water treatment. Vegetation, soil, and microbes all work together to treat contaminants in a wetland. They can treat a number of contaminants and different kinds of water, making them a versatile, viable option for many water treatment needs.

If you want to learn more about wetlands and other water treatment methods, be sure to check out this article and others like it on the Save the Water^TM website!

By Matthew Taylor, Associate Researcher & Writer for Save The Water | August 1, 2021

Treating water is already challenging enough. Yet in remote and underdeveloped areas, water treatment comes with its own unique set of challenges. These challenges include technological limitations, cost, and the availability of different water sources. We must come up with reliable solutions to solve these challenges so that anyone, including those in remote and underdeveloped areas, can have access to clean water.

Geographic limitations

When a water treatment system goes down in a large city, it is usually repaired within hours or days by dedicated water treatment plant staff. They have access to parts and labor right away and can thus fix the problem quickly. Unfortunately, this luxury is simply not available in remote and underdeveloped areas.

There is a limited number of people available who can repair the system when it goes down, and communities in these areas often do not have the parts they need to repair them. They are stuck waiting for days or weeks for parts to be shipped to them. If they cannot fix the system themselves, they must wait for a technician to come from a faraway place. In the meantime, they do not have access to clean water from their water treatment system. They are forced to boil their water, for example, or use bottled water to meet their needs.

Technological limitations

Remote and underdeveloped areas have limited resources available to them because they can be so isolated. For example, these areas may not have reliable electricity, so they cannot always rely on water treatment systems that utilize electricity. They may also not have the space required for certain water treatment systems, meaning that they have to find another solution. This solution might not necessarily be the right fit for these areas, but it is the only option that communities may have.

Cost

Communities located in remote or underdeveloped areas might not have the funding available to spend on a fancy water treatment system. In these areas, communities are often small. They receive less government funding and can collect less tax money from their residents. Communities might have to settle for water treatment systems that cannot meet their needs as they are unable to invest in a system that works for them.

Availability of different water sources

Tap water is available in most cities and towns in developed areas. However, tap water might not be readily available in remote and underdeveloped areas. Residents of these areas may get their water from wells or streams, for example. The quality of the water from these sources can vary significantly. There might not be a one-size-fits-all water treatment solution in the community.

Looser regulations

There are usually many more drinking water regulations in cities than there are in remote and underdeveloped areas. These regulations make it easier to treat water because there are much stricter rules to follow. However, regulations for water outside of cities tend to be loose in comparison. There are also more kinds of water sources to consider, each with its own contaminants and challenges. This issue means that a water source might not fit under specific regulations like it would in a city. The water might not be as clean as it should be before being consumed.

What can we do?

Ideally, water treatment systems in remote and underdeveloped areas would avoid the issues previously mentioned in this article. In a perfect world, water treatment systems in these areas would have certain qualities:

• They would be easy to repair and have minimal components that would need specialized parts or labor to repair.
• Being adaptable so they can meet an area’s unique needs
• A backup battery or generator to power them so they do not have to use an unreliable electric grid
• Affordability, so that even the communities with the least money could have access to clean water
• The ability to treat water from different sources of water unique to the area, taking into account that separate water treatment systems might be needed for bodies of water like a river and other sources of water like wells, which could mean that there is a household water treatment and storage system in every home
• Coverage under stricter regulations to have consistently cleaner water throughout a region, regardless of whether the water is for a large community or a remote or underdeveloped area

Some of the biggest challenges we have when it comes to water treatment in remote and underdeveloped areas include geographic limitations, technological limitations, cost, the availability of different water sources, and looser regulations. If we can come up with solutions to these challenges that have the qualities mentioned above, challenges with water treatment in remote and underdeveloped areas would be much easier to solve. Follow Save The Water for more water news!

A mine reaches the end of its life cycle when the supply of ore that is being extracted, such as copper or gold, is exhausted. Most of the rock that is mined becomes waste. The desired ore makes up only a small fraction of the rock. In Canada, for example, only 1% of what is mined when mining copper is valuable. The other 99% is waste.

When using the froth flotation method, for example, the mined rock is ground and treated with chemicals which separate the ore from the rock. The solution is then mixed with water so the valuable ore floats to the surface of the mixture. The slurry of unusable rock and wastewater is then sent to a tailings pond. Tailings ponds are highly toxic because of the chemicals used in the extraction process as well as the presence of toxic material such as heavy metals. When undergoing mine decommissioning, toxic materials must be dealt with.

Why a water treatment plan?

One of the most important parts of the mine decommissioning process is the water treatment plan. Companies cannot simply walk away from their responsibility to deal with toxic tailings ponds. They are legally obligated to bring the water back to a state of minimal toxicity. This state is determined by regulatory bodies. Sometimes a company does not adequately address the cleanup process. The public can use the following information to advocate for mine cleanup and water treatment.

An added complication is that not all mines are treated the same. A diamond mine, for example, has far different water treatment needs than a lithium mine. Although jurisdictions around the world have different requirements for water treatment, the following is a general plan for water treatment at any mine.

1. Know the mine

As previously mentioned, all mines are different. One gold mine, for example, may have significantly different tailings treatment requirements than another gold mine because of differing contaminants in the surrounding rock. To create an effective treatment plan, information such as what minerals were mined, the use of chemicals such as cyanide, and the volume of water to treat must be known. These factors can significantly affect how water will be treated at a decommissioned mine. Not all water treatment methods are suitable for all applications.

2. Know any limitations

Water treatment plans can vary significantly depending on any relevant limitations. If a mine is very remote, for example, it might not be very practical to actively treat the water. It might instead be better to install a passive treatment system like a limestone bed, for example. This system will reduce the water’s alkalinity and needs to be checked infrequently.

3. Know the regulatory requirements

For wastewater to be considered safe and up to regulatory standards, it is important to know the regulatory requirements of the jurisdiction where the mine is located. Some rules, for example, may require lower concentrations of toxic chemicals than others. Obviously, the cleaner the water, the better. The water being treated at a decommissioned mine must at least meet the requirements set out in the regulations. For example, the Alberta Tier 1 Soil and Groundwater Remediation Guidelines state that arsenic concentration in water can be a maximum of 0.005 mg/L.

4. Know the mine’s water treatment needs

Mining different minerals means that water treatment needs will be different at every mine. A number of tests to know the conditions of the water needing treatment will likely need to be done to come up with an effective treatment plan. The pH of the water must be changed if it is too acidic or too alkaline, or if toxic heavy metals like cadmium or lead from the water may need to be removed. One such removal process is membrane filtration. Iron-removing bacteria may also be used.

Bottom line

Even if the same mineral is being extracted, different mines have different water treatment requirements. Whoever is responsible for the water treatment plan must know as much as they can about the mine and its requirements. If they do, they can prevent dangerous consequences such as water leaching into the surrounding soil. Often, this information is available to the public and can be used by concerned citizens to advocate for mine cleanup or repurposing. The necessary information can include information about the mine itself, any limitations or constraints, any regulatory requirements, and what the water in a tailing pond consists of.

A company can fulfill its responsibility to treat wastewater and help to remediate a decommissioned mine site. The company’s actions making the water safer for people, animals, and the environment.

Chlorine in drinking water can have toxic effects on the human body, according to a study earlier this year. Long-term exposure to chemicals in drinking water can cause cancer.

Chlorine is a common chemical used to clean the drinking water supply in the United States. It kills parasites, bacteria, viruses, and germs in our water, but how safe is it?

Researchers found that chlorine may create harmful byproducts in water. This happens when it interacts with phenols. Phenols are naturally occurring chemical compounds in water. Also, phenols are in everyday hygiene products. Phenols may produce carcinogens (substances promoting cancer) upon contact with chlorine.

History, benefits, and dangers of chlorinating drinking water 

Chlorine has disinfected our water supply since the early 1900s. Because of it, we see fewer cases of diseases such as typhoid and cholera. But researchers discovered that the contact between chlorine and other chemical compounds in water can harm the human body. 

What do scientists suggest for the future of water treatment?

Chlorine isn’t the only way to disinfect drinking water. Removing chlorine from water wouldn’t make the water supply less safe, says Carsten Prasse, the lead author of the study. For instance, European countries do not chlorinate their water. Alternatives include “ozone, UV treatment or simple filtration.” But Prasse warns that researchers should also further test these methods for potential health effects. 

Prasse suggests researchers do more studies on the health impact of disinfectants, such as chlorine, on the water supply. If regulators know how to test the effects of disinfectants, they can take action to treat our water more safely.

What you can do now to stay safe and informed

Chlorine as a disinfectant to our water may be around for a while until researchers conduct more studies. Here’s what you can do now to stay safe and informed:

• Check your water bill. Water suppliers release an annual report that tells you where the water comes from, what contaminants are in at, and at what levels. You can get a copy of the Consumer Confidence Report anytime through the Environmental Protection Agency (EPA) as well.
• Take a look at the EPA’’s reports on groundwater and drinking water for your area.
• Search your zip code on a Tap Water Database
• Purchase a water filter. There are several types of filters, so here is a guide to find the right one for your home. Foodandwaterwatch.org notes that a filter with carbon reduces the amount of chlorine in the water. 

The presence of pharmaceutical compounds in water supplies has been well documented for several decades, but the exact threat posed and recommended responses have been debated just as long. The health impact on humans and wildlife remains a concern for many scientists and policy makers. Unfortunately, the water treatment and sewage systems are not currently able to address this contamination. However, researchers are developing new methods to test and treat water. A promising new technique has been developed in which “supermolecules” detect and remove pharmaceuticals from water, leading to potential implications for improved and on-site water treatment.

A growing problem

Researchers are exploring the extent to which pharmaceuticals are found in the water supply; however, it is clear that this is an emergent issue. People often dispose of leftover pharmaceuticals down the drain, rather than through local drop-off collection programs or in a safe manner at home.2 Hospitals are also a source of pharmaceuticals that appear in municipal wastewater.6 In addition, individuals often only metabolize a portion of the drugs they ingest, meaning that some of the compounds are ultimately expelled into the sewage system, though removal proves difficult. In fact, in a 2013 study, the International Joint Commission determined that only half of prescription drugs in sewage were removed by treatment plants.1 Ultimately, the water treatment and septic systems are not equipped to address this source of contamination.

Pesticides and herbicides, hormones from contraceptive birth control, beta-blockers, antibiotics, and other pharmaceutical compounds have been discovered in water reservoirs, water treatment plans, and watersheds. Many scientists are concerned about potential contamination of drinking water. The Associated Press also conducted its own independent research and found pharmaceuticals present in the drinking water supplies of at least 41 million Americans.3 Although these compounds are only present at very low levels, further research is underway to determine the potential effects. In addition, there are concerns that contamination by antibiotics, in particular, may affect people’s health by cultivating an environment where bacteria can develop resistance to antibiotics.4

The extent of the impact on human health is under study, and there is also emerging evidence that there is an effect on the health of aquatic wildlife. Scientists are noticing that some fish populations have shown abnormalities, including male fish growing female egg cells.5 This is suspected to be the result of exposure to hormone-disrupting water pollution, including estrogen from birth control pills. Fish wildlife are extremely sensitive to their environments, but this issue does illustrate potential water quality concerns.

Making waves in water testing and treatment

Researchers from the University of Surrey have published research that showcases a new “supermolecule” that can detect and remove pharmaceuticals from water in an effective and environmentally friendly manner.7 This supermolecule, a derivative of calixarene, interacts with and extracts common pharmaceutical compounds from water.3 The receptors bind selectively with the pollutant so that they can be removed This method may be applicable to many kinds of materials and compounds. This research is particularly promising because it may potentially allow for on-site water quality monitoring, rather than testing samples in a separate laboratory. In addition, this method may emerge as more cost effective than other technologies, such as ozonation and carbon filtration, which are very expensive.

Other promising research and policies include the development of pharmaceuticals that the body better retains, public awareness campaigns on drug disposal options, upgraded water treatment infrastructure, and additional public health research. This is an issue that will not go away anytime soon. A multi-pronged approach will be needed in order to tackle the existing water quality concerns and prevent future contamination.

References

1. Brian Bienkowski. November 22, 2013. “Only Half of Drugs Removed by Sewage Treatment.” Scientific American. Retrieved from https://www.scientificamerican.com/article/only-half-of-drugs-removed-by-sewage-treatment/
2. California State Board of Pharmacy. 2008. “Don’t Flush Your Medicines Down the Toilet!” Retrieved from http://www.pharmacy.ca.gov/publications/dont_flush_meds.pdf
3. Jeff Donn, Martha Mendoza, and Justin Pritchard. 2008. “Pharmaceuticals found in drinking water, affecting wildlife and maybe humans.” The Associated Press. Retrieved from http://hosted.ap.org/specials/interactives/pharmawater_site/day1_01.html
4. Katie Colaneri. May 15, 2014. “What is the long-term health impact of pharmaceuticals in our water?” State Impact. Retrieved from http://n.pr/2unFCvP
5. Lindsey Konkel. February 3, 2016. “Why Are These Male Fish Growing Eggs?” National Geographic. Retrieved from http://bit.ly/1VLjweG
6. Monica Escola Casas, et. al. October 2015. “Biodegradation of pharmaceuticals in hospital wastewater by stated Moving Bed Biofilm Reactors (MBBR).” Water Research. Retrieved from http://bit.ly/2vlXr2U
7. Phys.org. April 10, 2017. “New breed of supermolecule ‘hunts down’ harmful drugs and removes them from water.” Retrieved from https://phys.org/news/2017-04-supermolecule-drugs.html