Effects of Heavy Metallic Ions on Electron Transport System Activity of Anaerobic Sludge
重金属对厌氧污泥电子传递体系活性影响研究

The influence of Ni2+, Cd2+ and Cu2+ on electron transport system (ETS) activity of anaerobic 2-chlorophenon degradation sludge, as well as the effect of acclimation on microbial resistance to metallic toxicity, was investigated. The inhibitive effect of heavy metals on ETS activities acted within 0.25 h, and metallic toxicity aggravated with the increasing amount of metallic ions. The relative strength of inhibition was Ni2+>Cd2+>Cu2+ and was mainly dependent on the metallic ion concentration in solution. Acclimation with metals of low concentration was proved to be a good way to improve the microbial resistance to heavy metals. After domestication, the toxicity of Cu2+ decreased 10%, and the maximum decreasing percentage of Cd2+ inhibition was more than 40%, while the effect of Ni2+ transferred to be in favor of ETS activity with the optimal concentration of 70 mg/L. The particularly active effect of Ni2+ was probably due to the capability of Ni2+ to form regular tetrahedron chelate compounds. The relative amelioration of microbial resistance was Ni2+>Cd2+> Cu2+.