Effects of hydraulic residence time on metal uptake by activated sludge

Ozbelge, TA
Özbelge, Hilmi Önder
Tursun, M
The combined uptake Of Cu2+ and Zn2+ by activated sludge (biomass) was investigated at steady state in an activated sludge process (ASP) without recycle (namely, once-thro ASP), for different values of influent metal concentrations and hydraulic residence time in the range of 2.5-40 h. The experiments were performed at a constant pH of 7 and temperature of 25 degreesC. The results showed that the percentage removal of both copper and zinc by activated sludge increased with the increasing residence time; moreover, the percent metal uptakes were higher for both metals at the low level of influent metal concentrations [rho(Cu2+) = 1.5 mg/L and rho(Zn2+) = 9 mg/L], than those at the higher level of concentrations [rho(Cu2+) = 4.5 mg/L and rho(Zn2+) = 27 mg/L]. The least represented forms of both Cu2+ and Zn2+ in activated sludge were their sulfides, and the dominant metal forms were found to be 'organically bound' for both of the metals, Zn2+ and Cu2+.

Citation Formats
T. Ozbelge, H. Ö. Özbelge, and M. Tursun, “Effects of hydraulic residence time on metal uptake by activated sludge,” CHEMICAL ENGINEERING AND PROCESSING, vol. 44, no. 1, pp. 23–32, 2005, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/51523.