{"id":115911,"date":"2022-08-05T14:32:25","date_gmt":"2022-08-05T18:32:25","guid":{"rendered":"https:\/\/savethewater.org\/?p=115911"},"modified":"2022-08-05T15:02:50","modified_gmt":"2022-08-05T19:02:50","slug":"coal-fly-ash-as-membrane-filters-in-wastewater-treatment","status":"publish","type":"post","link":"https:\/\/savethewater.org\/coal-fly-ash-as-membrane-filters-in-wastewater-treatment\/","title":{"rendered":"Coal Fly Ash as Membrane Filters in Wastewater Treatment"},"content":{"rendered":"

By Sakshi Kabra Malpani, Publishing Associate: Researcher and Writer at Save the Water\u2122 | August 5, 2022\u00a0<\/span><\/p>\n

Coal fly ash, a by-product of thermal power stations, has always been a potential threat to the environment. But nowadays, it can be converted into many meaningful products including <\/span>membrane filters<\/span><\/a>. Membrane filters are cheaper and eco-friendly, so they have replaced traditional water filtration techniques like <\/span>distillation<\/span><\/a>, <\/span>evaporation<\/span><\/a>, <\/span>sedimentation<\/span><\/a>, etc.<\/span><\/p>\n

How is Coal Fly Ash a Threat to the Environment?<\/b><\/h2>\n

The world meets about <\/span>40% of its electricity demand by burning coal in thermal power plants.<\/span><\/a> This coal burning produces huge amounts of coal fly ash which needs to be disposed of in eco-friendly ways. Coal fly ash has <\/span>toxic heavy metals like cadmium, mercury, arsenic, chromium, nickel, and cobalt.<\/span><\/a> These poisonous elements can leak out of it and contaminate the environment. They can also impact human health with <\/span>skin and lung infections, cancer, nausea, vomiting, malfunctioning of vital organs, etc.<\/span><\/a><\/p>\n

Trends in Recycling of Coal Fly Ash<\/b><\/h2>\n

In the past few years, researchers have worked very hard to develop new ways for recycling coal fly ash. Now, it has been used in <\/span>adsorption<\/span><\/a>, <\/span>catalysis<\/span><\/a>, <\/span>wastewater treatment<\/span><\/a>, <\/span>ceramic materials<\/span><\/a>, <\/span>building materials<\/span><\/a>, <\/span>cement industries<\/span><\/a>, <\/span>horticulture<\/span><\/a>, and more. Apart from these uses, costly metal and metal oxides can also be extracted from it.<\/span><\/p>\n

How do Membrane Filters Work in Water Treatment?<\/b><\/h2>\n

Membranes are semi-permeable, porous sheets that can separate dissolved solids and contaminants from water when some driving force is applied. They are generally used to treat and process wastewater, groundwater, drinking water, rainwater, etc. Depending upon the water quality and types of impurities in it, a membrane filter is selected for water treatment. It helps in the removal of particles, microbes, micropollutants, harmful ions like <\/span>fluoride<\/span><\/a>, chloride, cyanides, and other fouling organic materials. Based on the pore size of membranes and the size of impurities to be filtered out, there are four common methods of membrane filtration in water treatment, namely, <\/span>microfiltration, ultrafiltration, nanofiltration and reverse osmosis.<\/span><\/a><\/p>\n

Different Types of Membrane Filters<\/b><\/h2>\n

There are several commonly used membrane filters<\/span>:<\/span><\/p>\n