need to sponge out heavy metals from industrial wastewater? Try seaweeds. Two researchers at the Kochi-based Central Marine Fisheries Research Institute has found that certain sea plants found along the Gulf of Mannar coast may not only help remove heavy metals such as cadmium and lead but also allow their recovery.

Sargassum wightii, a brown algae, is as effective or better than activated carbon and natural zeolites that are conventionally used to remove heavy metals from industrial effluents, say P Kaladharan and V Vinoj Kumar in a paper published in Current Science (Vol 90, No 9, May 10, 2006). Besides, as the seaweeds wash ashore, they can be easily collected for use, he adds.

The scientists found the seaweeds produce two acids