Project Lead(s): Aman Ullah
About 140 million people throughout the world are exposed to dangerously high concentrations of arsenic in their groundwater, with the highest impact in developing countries, especially in South Asian countries such as Bangladesh, India, Nepal, Vietnam, Pakistan and China.
Conventional technologies – based on coagulation, flocculation, reverse osmosis, ion exchange, precipitation and surfactant-enhanced ultrafiltration – have been developed to remove arsenic from water but have numerous drawbacks, making them unsuitable and unsustainable for small-scale industries.
The main idea of the project was to develop a biosorbent material from waste protein (chicken feathers) to remove arsenic from contaminated water.
Previous research has shown that chicken feathers can be used to remove organic dyes and heavy metal ions from waste water because of their high surface area and several reactive functional groups.
Results show that, after chemical modification, feathers have a higher dye/ion uptake.
This project studied structural changes during modification, and extended the use of modified chicken feathers by using them to design arsenic removal filters.
Chemically, several modifications of feathers were generated by treatment with different doping agents.
The extent of modification of the filter-containing material was evaluated by characterization techniques, and the adsorption efficiency was evaluated using kinetic and isothermal studies of the biosorption.
The study showed that modified chicken feathers can effectively be employed to remove arsenic from contaminated water sources.
The modification involving esterification showed the highest arsenic uptake because of the overall anionic charge depression on the surface of the modified feathers.
Overall, the filter managed to remove 115µg of arsenite per gram of developed biosorbent from arsenic-contaminated water, demonstrating its ability to reduce concentration to the safe maximum admissible level (10 μg/L) set by the World Health Organization (WHO).
Knowledge about the project was disseminated in the Royal Society of Chemistry Advances and the Journal of Hazardous Materials. The study was further extended to explore the removal of several metals and organic contaminants from industrial wastewater. Two patent applications have been submitted and two more articles are underway.
There are plans to develop about a dozen filters at the village level, to evaluate their feasibility and validate their effectiveness and reproducibility by applying them for onsite water purification and removal of arsenic from different affected areas.
In order to interest water purification companies, discussions are ongoing on the potential of working with NGOs and researchers to do scale-up trials to remove additional metals.