The Biosorption Study Of Heavy Metals In Mine Wastewater By Immobilized Bacteria

The biosorption of heavy metas in mine wastewater by immobilized bacteiria was studied in this paper, mainly including the water quality analysis of Dabaoshan mine area, the screening and the identification of bacteria efficiently adsorbing heavy metals, the immobilization of bacteria and the research of best immobilization factors, the process explore of immobilized bacteria, the treatment of mine wastewater.The concentration of Cu, Zn, Fe, Ni, Cr (total), Cd and Pb in the water of Dabaoshan mine area was analyzed. The analysis results showed that the pollution of the area around Dabaoshan is very serious; further more, heavy metals were detected in the well water of a farmer house of Shangba country.The bacteria efficiently adsorbing heavy metals were screened, and the biosorption capability of heavy metals was measured, and the bacterium was identified as Staphylococcus auricularis. The experimental results showed that Cu, Zn could be efficiently accumulated by S. auricularis. The removal ratios of 100mg/L Cu and 50mg/L Zn were 77.1%, 56.3% respectively, when the strain dosage was 15g/L(wet weight). Furthermore, the biosorption efficiency was good even in acid conditions, making it possible for the future application in mine wastewater.The bacteria were immobilized, and the best immobilization factors were discussed, including the selection of matrix, the pretreatment of the bacteria before immobilization, the optimization of immobilization factors. The desorption of heavy metals after adsorbed by immobilized bacteria was researched, the best factors of desorption were discussed. The experimental results showed that Na-alginate is a better kind of matrix. The production was easy using Na-alginate as matrix. The mechanical strength was good. The scanning electron microscope micrographs of immobilized bacteria showed that there are still many millipores in the bacteria immobilized, which would facilitate the inleakage of heavy metals. The removal ratios of 100mg/L Cu and 50mg/L Zn were exceeding 95% and 80% in the best conditions respectively.The treatment technology was explored using the fluidized bed, and the influence...