58 Chromium deoxification by flixed-film bioreactors

摘要

The hexavalent form of chromium, chromate, is highly toxic and is known to be both carcinogenic and mutagenic to living organisms including humans~(1,2). Higher than allowable concentrations of chromate are detected in groundwater and surface water receiving industrial wastewater. Chromate is relased into water boides from a variety of processes such as photographic film or negative making, electroplating, leather tanning, and wood proeservation~3. Recent studies have shown that cetain species of bacteria are capable of catalytic transformation of chromate, Cr(VI), into the less toxic trivalent form, Cr(III);~(4-10)