Journal of Environmental Analytical Chemistry

Temperature Effects on Zn(II) Toxicity to Metabolisms of Polyphosphate Accumulating Organisms in Aerobic and Anaerobic Conditions

Abstract

Tsai YP, Lu MS, Lin JW, Chou CC, Hu LY

This study explores the influence of temperature on the tolerance of polyphosphate accumulating organisms (PAOs) to Zn(II) in enhanced biological phosphorus removal. The results show anaerobic and aerobic metabolisms of PAOs decreased with increasing Zn(II) concentration varying between 0-2 mg L-1 and temperature indeed affected inhibitive degrees. Furthermore, Zn(II) is more toxic to anaerobic poly-P hydrolysis and glycogen degradation at 10°C than at 20 and 30°C. For anaerobic polyhydroxyalkanoate (PHA) synthesis, Zn(II) had a highly inhibitive effect at 10°C too. The inhibitions of PAOs aerobically taking up phosphorus, degrading PHA and replenishing glycogen in the presence of Zn(II) were amplified at 10°C. The metabolism of aerobic PHA degradation at 10°C was completely terminated and the aerobic replenishment of glycogen at 10° C was also completely terminated at 0.1 mg L-1 of Zn(II) due to the complete inhibition of aerobic PHA metabolism, which provides the required reducing power for synthesizing glycogen.