Article courtesy of Simon Crompton | November 2, 2014 | Digital Journal | Shared as educational material
In a novel approach to filtering water, researchers in China and Saudi Arabia have come up with a way of using ash from cigarettes to remove arsenic from drinking water.
According to Gizmodo, the technique would have considerable use in dealing with contaminated drinking water in the developing world.
Arsenic in water supplies is a serious health hazard in many parts of the world. Countries like Bangladesh have high levels of naturally occurring arsenic compounds in the soil that leaches into the water supply. Industrial countries have a similar problem when arsenic from natural and man-made sources pollute the water supply and cause a hazard to public health if it is not detected.
The richer the nation, the more likely they are to have filtration or absorption options in place. In the developing world, however, these expensive options are not available and, when they are, they are unaffordable.
A simple water filter system, using activated carbon to attract and remove the arsenic compounds, is the most cost-effective and simplest way to purify drinking water. Ash from a cigarette can be treated and used as the activated carbon.
“When people smoke, incomplete combustion emerges as air is sucked through the tobacco within a short time. Thus, a certain amount of activated carbon is formed and incorporated into the cigarette soot,” wrote He Chen and his co-authors in a study done for Industrial & Engineering Chemistry Research.
Research done at the Chinese Academy of Sciences has found that coating the cigarette ash with aluminum oxide stripped out 96 percent of arsenic from contaminated water in tests. This meets the standards set by the World Health Organization (WHO) for arsenic filters.
The team tested the coated ash on contaminated ground water from Inner Mongolia that was contaminated with arsenic. The filter itself could be reused up to six times with no loss of effectiveness.
With the ready availability of both cigarettes and aluminum oxide in developing countries, the team believes that filters created with their method would be a particularly effective solution to arsenic pollution in public water supplies.