Toxic
Heavy
Metals - Wastes from thermal power stations, metal and refining industries, electroplating units, sewage sludge, tanneries etc. contain toxic heavy metals. These can be removed by physico - chemical means, such as ion exchange, precipitation, activated carbon adsorption and electrolysis. But each of these has some drawbacks and limitations.
Therefore, microbial biomass has been used for removal of heavy metals. Microbes are being exploited for removal, concentration and recovery of these metals. Microbes adsorb these metals actively or passively. Biomass produced from Zooglea ramigera, a polysaccharide secreting organism adsorbs copper and cadmium upto the levels of 300 and 100 mg of metal/g dry wt. respectively.
