How sewage can clean up rivers

时间:2019-03-06 07:10:02166网络整理admin

By Diane Martindale MOPPING up river pollution might not always be a good idea. A little sewage may protect wildlife by locking up toxic metals. George Luther of the University of Delaware in Lewes and his colleagues examined samples from 20 rivers on the eastern seaboard of the US. They found that sulphides, which mostly come from sewage, can “mop up” metals by imprisoning them in sulphide clusters. The clusters trap common metals such as iron, zinc and copper, as well as more toxic metals such as silver,