Title: | Toxic effects of cadmium (Cd(2)(+)) on anaerobic biomass: kinetic and metabolic implications |
Author(s): | Mockaitis G; Rodrigues JA; Foresti E; Zaiat M; |
Address: | "Hydraulics and Sanitation Department, Sao Carlos Engineering School, Universidade de Sao Paulo (SHS/EESC/USP), Av. Trabalhador Sao-Carlense 400, CEP 13.566-590, Sao Carlos, SP, Brazil" |
DOI: | 10.1016/j.jenvman.2012.03.056 |
ISSN/ISBN: | 1095-8630 (Electronic) 0301-4797 (Linking) |
Abstract: | "Cadmium ion (Cd(2+)) 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 mg Cd(2+) L(-1) the organic matter removal efficiencies were 84%, 82%, 72% and 52%, respectively. At influent concentration of 6.2 mg Cd(2+) L(-1) the reactor had reached its limit for cadmium toxicity. In the removal of dissolved organic matter, the first-order apparent kinetic coefficients (k(1)(app)) were 0.84, 0.67 and 0.10 h(-1) for the operations with 0.0, 0.4 and 4.4 mg Cd(2+) L(-1), respectively. The apparent inhibition coefficient for cadmium (k(i)(app)) was 1.69 mg L(-1). Despite the toxic effects of cadmium on anaerobic organic matter removal at large Cd(2+) concentrations, the results demonstrated that the anaerobic process was suitable for cadmium concentrations below 29.8 mg Cd(2+) L(-1), considering the bioavailable fraction of adsorbed cadmium in the support when the cadmium influent concentration was 6.2 mg Cd(2+) L(-1)" |
Keywords: | "Adsorption Anaerobiosis Archaea/drug effects/metabolism Bacteria/drug effects/metabolism *Biomass Bioreactors/*microbiology Cadmium/*toxicity Equipment Design Kinetics Polyurethanes Sewage Temperature Volatile Organic Compounds/metabolism Waste Disposal, ;" |
Notes: | "MedlineMockaitis, G Rodrigues, J A D Foresti, E Zaiat, M eng Research Support, Non-U.S. Gov't England 2012/05/12 J Environ Manage. 2012 Sep 15; 106:75-84. doi: 10.1016/j.jenvman.2012.03.056. Epub 2012 May 9" |