The Immobilized Microorganism Method Treats Electroplating Wastewater Containing Chromium

The development of electroplating industry yields a large number of chromium-containing wastewater.As we know,the Cr(?)is toxic for human.Therefore,the treatment of chromium-containing wastewater has become one of the key areas of environmental protection.The traditional method of treating chromium containing wastewater consumed a lot of energy and was likely to cause secondary pollution.The shortcomings of traditional methods limit its application on the project.The treatment of wastewater with immobilized microbial is affordable,environmental-friendly and widely applicable.In order to investigate the feasibility of applying immobilized microbial wastewater on the treatment of chromium containing wastewater,the related research was carried out.In this study,a strain with ability of Cr(?)removing was isolated from Harbin Measuring Tool Factory.This bacterium has high Cr(?)resistance level of 250mg/L.Adding glucose has no effect on the removing of Cr(?).The optimal conditions of Cr(?)removing was: pH 7.0,35?,inoculation volume10%(v/v).Under this condition,When the Cr(?)concentration was? 10mg/L,Cr(?)was removed 99%;When the Cr(?)concentration was 100mg/L,Cr(?)was removed 37.80%.In order to find the optimum immobilization condition of Cr(?)removing of J2.The effect of J2 immobilization conditions was investigated.It is found that the optimum condition was: 9.5%PVA,1.0%SA,embedding ratio1/2,3%borate,1% calcium chloride,reaction time 28 h.The final results of Cr(?)removing was 63.54±3.50%,which was closed to the predicted results.The result was credible.The application of immobilized J2 on the treatment of chromium-containing wastewater shows that: the optimal condition of immobilized J2 was pH 7.00,35 ?,balls/ liquid 1/10.Under this condition,When the Cr(?)concentration was? 15mg/L,Cr(?)was removed 99%;When the the Cr(?)concentration was 100mg/L,Cr(?)was removed 63.54±3.50%.The removal rate of Cr(?)is improved 173% compared to the free bacterium;The immobilized J2 was able to reused for four times.The application immobilized J2 on the pratical chromium-containing wastewater shows that: When pH 7.00,25?,balls/ liquid 1/10.Add C/N,When the Cr(?)concentration in the actual electroplating wastewater was? 10mg/L,Cr(?)was removed 99%;The result of identification about morphology,physiology and biochemitry,and molecular biology shows that J2 belongs to Acinetobacter nosocomialis.