Teabag-style filter removes arsenic from water
Cellulose sachets loaded with iron-oxide nanoparticles and eggshell powder could offer a simple, low-cost solution.
Researchers at the City University of New York, USA, say they have developed a teabag-style filter that can remove arsenic ions from contaminated water, offering a low-cost water treatment option for communities lacking advanced infrastructure.
Arsenic contamination affects groundwater in many parts of the world. Conventional treatment methods such as reverse osmosis can be expensive and difficult to deploy in regions without wide-scale water treatment.
In a sample designed to represent well water in Bangladesh, the filter reduced arsenic content to below the World Health Organization’s drinking-water limit of 10mcg/L.
The teabags can also be rinsed, washed in alkaline solution, dried and reused up to five times, although removal efficiency fell by around 20% with each reuse, report the scientists.
In laboratory tests, one teabag reportedly removed at least 90% of arsenic ions from water, and in one six-hour trial removed more than 98% from 50ml of contaminated water.
The researchers estimate the system could treat water for about US$0.07/L.
