Potential Use of TCS and PNP to Reduce Activated Sludge Production

Activated sludge processes are widely used in wastewater treatment plants (WWTPs) but they also generate large quantities of excess sludge, the handling and disposal of which uses large percentage of the annual operation cost. A class of chemicals, referred to as uncouplers, with the ability of generating energy spill inside microbial cells have shown potential in reducing activated sludge production. This study assessed the effectiveness of two uncouplers: 3,3',4',5- tetrachlorosalicylanilide (TCS) and paranitrophenol (PNP) in reducing sludge production. The experimental set-up comprised three sequencing batch reactors (SBRs), the feed to which was spiked with the uncoupler. The results showed that 13.5% and 25% reduction in sludge production can be achieved using0.5 mg/L TCS and 20 mg/L PNP, respectively, in the influent