Influence of Heavy Metal on activated Sludge activity: DO and SOUR monitoring

Abstract

The objective of this study is to evaluate the inhibitory effect of heavy metals on activity of activated sludge microbes, under sequencing batch reactor (SBR) operation, based on dissolved oxygen (DO) and specific oxygen uptake rate (SOUR) monitoring. The SBR systems were operated with Fill, React, Settle, Draw and Idle periods in the time ratio of 0.5 : 3.5 : 1.0 : 0.75 : 0.25for a cycle time of 6 hours. It was observed that the addition Cu(II), Cd(II) and combined Cu(II) and Cd(II)-containing wastewater into SBR A, B and C, respectively, had caused deterioration in bio-oxidation processes carried out by activated sludge microbes. From SOUR study, Cu(II) exhibited more toxic to the activated sludge microbes compared to Cd(II).