The influence of temperature on metabolisms of phosphorus accumulating organisms in biological wastewater treatment plants in the presence of Cu(II) toxicity

Abstract

The purpose of this study was to study how temperature variation affects the tolerance of phosphorus accumulating organisms (PAOs) in a toxic environment. To exclude the interference of glycogen accumulating organisms (GAOs), shock loading experiments were conducted to study the effect of Cu(II) toxicity on the metabolisms of PAOs in 10, 20, and 30 °C conditions. The experimental data showed that the temperature effects on aerobic phosphorus uptake, PHAdegradation, and glycogen synthesis were remarkable in the presence of Cu(II). Nevertheless, insignificant effects on anaerobic phosphorus release and PHA synthesis were found. The largest inhibition of PAO metabolism occurred in the low temperature case (10 °C). This study also experimentally demonstrated the loss of PAO metabolic ability in the subsequent aerobic stage, after the anaerobic stage. The presence of Cu(II) toxicity mainly resulted from the inhibition of biochemical reactions in the aerobic stage, and it was irrelevant to the inhibition of previous anaerobic metabolisms.