Removal Mechanism of Heavy Metal by Desulfovibrio desulfurican

摘要

A pure sulfate reducing bacteria of Desulfovibrio desulfurican was used to treat the wastewatcr with different dosages of Cd2+.Accumulated H2S in the systems varied between 0.28 and 0.35ml when the Cd2+ was less than 28mg/L.The removal efficiency of Cd2+ and SO42 in all reactors reached 99％.At same time the role of extracellular polymeric substances (EPS) in the removal of Cd2+ was studied.The content of EPS increased with the increasing of Cd2+ from 0 to 11.2mg/L,and decreased with a further increase to 28mg/L.A lowest EPS production was obtained when the concentration of Cd2+ was 28mg/L.Cd2+ in the EPS solution increased with the increase of initial Cd2+.A maximum value of 11％ of the removal of Cd2+ could be attributed to the EPS.