Adsorption performance investigation of heavy metal copper in acid mine drainage by the Klebsiella oxytoca

摘要

The acid wastewater from nonferrous metal mine causes serious environmental pollution,and affect human production and life because of its low pH and high content of heavy metal ions.A strain capable of adsorbing copper ion was isolated at the acidic condition through the domestication and screening.It was identified as Klebsiella oxytoca.The results of single factor optimization test indicated that the best carbon source of the strain was the mixture composed of 0.7 g.L-1 sodium acetate and0.6 g· L-1 of xanthate and the best nitrogen source is 0.7 g· L-1 ammonium sulfate.Under the conditions of best carbon and nitrogen source conditions,4 g· L-1 strain concentration,30℃ temperature and 4 had sorption time,the optimal conditions influencing the copper removal rate were obtained at pH 3.0 and100 mg· L-1 Cu2+,and the adsorption efficiency of Cu2+ reached 59.7％.The process of the strain adsorbing Cu2+ is in line with Langmuir isotherm model which is priority to surface adsorption.Infrared spectrum analysis showed that the chemical changes happened in the groups of-OH,-NH and-CONH2 in the absorption process,while the adsorptions of-CH,-C=O,C-O and C-N groups on the bacteria were the physical adsorption.