Toxic effects of cadmium (Cd²⁺) on anaerobic biomass: Kinetic and metabolic implications

详细信息	查看全文 | 推荐本文 |

• 作者：G. Mockaitis^a ; J.A.D. Rodrigues^b ; E. Foresti^a ; M. Zaiat^a ; ^{zaiat@sc.usp.br}
• 关键词：Anaerobic processes ; Methanogenesis ; Toxicity ; Cadmium ; Anaerobic fixed bed bioreactor
• 刊名：Journal of Environmental Management
• 出版年：2012
• 期刊代码：82_03014797
• 类别：env
• 出版时间：15 September, 2012
• 卷：106
• 期：Complete
• 页码：75-84
• 文件大小：685 K

摘要

Cadmium ion (Cd²⁺) toxicity on anaerobic systems, used for organic matter removal, was assessed by studying its effect on kinetic parameters and metabolic changes. This fundamental study was performed in a continuous fixed bed anaerobic bioreactor that treated synthetic wastewater simulating domestic sewage. The biomass was immobilized on a fixed bed made of polyurethane foam. Under influent cadmium concentrations of 0.0, 0.4, 4.4 and 6.2聽mg Cd²⁺聽L^鈭? the organic matter removal efficiencies were 84%, 82%, 72%and 52%, respectively. At influent concentration of 6.2聽mg Cd²⁺聽L^鈭? the reactor had reached its limit for cadmium toxicity. In the removal of dissolved organic matter, the first-order apparent kinetic coefficients () were 0.84, 0.67 and 0.10聽h^鈭? for the operations with 0.0, 0.4 and 4.4聽mg Cd²⁺聽L^鈭?, respectively. The apparent inhibition coefficient for cadmium () was 1.69聽mg聽L^鈭?. Despite the toxic effects of cadmium on anaerobic organic matter removal at large Cd²⁺ concentrations, the results demonstrated that the anaerobic process was suitable for cadmium concentrations below 29.8聽mg Cd²⁺聽L^鈭?, considering the bioavailable fraction of adsorbed cadmium in the support when the cadmium influent concentration was 6.2聽mg Cd²⁺聽L^鈭?.