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Biosorption of heavy metals from simulated wastewater and the raw electroplating wastewater with 'BM (Biosorption of Metals) bacteria' were investigated in this study. The influence of initial pH, biosorbents dose, concentration of ions, contact time and temperature on biosorption capacity of Cr(VI) and Ni(II) were studied. The optimum pH for biosorption of Cr(VI) was found to be low, and the removal efficiency of Cr(VI) was 98.60% with 'BM bacteria' at pH 2. The removal efficiency of Ni(II) was increased with increasing the pH, and was enhanced up to 115% compared with the wastewater without BM bacteria. In this experiment, the 'BM bacteria' efficiently removed Cu(II), Ni(II), Cr(VI), Zn(II) and COD from the raw electroplating wastewater, and the removal efficiencies were 98.92%, 99.92%, 99.86%, 99.93% and 45.20% respectively. [ABSTRACT FROM AUTHOR]

Based on the fully coupled activated sludge model (FCASM), the novel model Tubificidae -Fully Coupled Activated Sludge Model-hydraulic (T-FCASM-Hydro), has been developed in our previous work. T-FCASM-Hydro not only describe the interactive system between Tubificidae and functional microorganisms for the sludge reduction and nutrient removal simultaneously, but also considere the interaction between biological and hydraulic field, After calibration and validation of T-FCASM-Hydro at Zhuji Feida-hongyu Wastewater treatment plant (WWTP) in Zhejiang province, T-FCASM-Hydro was applied for determining optimal operating condition in the WWTP. Simulation results showed that nitrogen and phosphorus could be removed efficiently, and the efficiency of NH4+-N removal enhanced with increase of DO concentration. At a certain low level of DO concentration in the aerobic stage, shortcut nitrification-denitrification dominated in the process of denitrification in the novel system. However, overhigh agitation (>6 mg·L-1) could result in the unfavorable feeding behavior of Tubificidae because of the strong flow disturbance, which might lead to low rate of sludge reduction. High sludge reduction rate and high removal rate of nitrogen and phosphorus could be obtained in the new-style oxidation ditch when DO concentration at the aerobic stage with Tubificidae was maintained at 3.6 g·m-3. [ABSTRACT FROM AUTHOR]