The humble coriander herb or cilantro has proven to have potential as biosorbent that can remove lead and other toxic heavy metals from water. It has been found that the coriander leaves have the ability to drink up heavy metals like lead and nickel that have leaked into groundwater. Studies are continuing to learn how well the herb can remove other heavy metals such as arsenic and mercury. The discovery was presented on September 12 at the 246th annual National Meeting and Exposition of the American Chemical Society (ACS) by scientist Douglas Schauer of Ivy Tech Community College of Indiana, USA, who led a research team to Mexico to find low-cost materials that could filter away industrial pollutants in groundwater. The research report has been published by the ACS.

Prof. Schauer says a handful of cilantro would neatly filter away lead from a pot full of highly contaminated water. The secret of cilantro’s purifying power lies in the structure of the outer walls of the microscopic cells that make up the leaves. The architecture of these walls makes them ideal for absorbing heavy metals. He also believes that dried cilantro could someday be packaged like teabags, or as reusable water-filter cartridges to remove heavy metals from impure water.

Though activated carbon is the most popular material used in water purifiers, it is too expensive for most developing countries. Coriander is an inexpensive way to purify drinking water being available in plenty.