Effect of Methyl Paraben on Sludge Reduction

Abstract

Activated sludge process is the most widely used sewage treatment technology, which accounts for more than 90% of urban sewage treatment processes and about 50% of industrial wastewater treatment processes. The essence of the activated sludge process is that microorganisms use the biodegradable organic matter in the sewage as nutrients for metabolism and meanwhile remove them, while large amounts of sludge would be generated inevitably during the sewage treatment process. The cost for the sludge treatment accounts for about 50% of the operating cost of the sewage treatment plant. In this study, the effects of uncoupler propyl paraben on sludge reduction and sewage treatment were conducted, and the results showed that the optimized concentration of propyl paraben for sludge reduction was 30 mg/l, which achieved 41% sludge reduction effect. Under the optimized propyl paraben concentration, the average removal rate of COD increased from 93.35% in the blank group to 94.53%; the average removal rate of NH4+-N increased from 65.47% in the blank group to 83.84%; the average removal rate of PO43--P from the 58.47% in the blank group increased to 67.36%; meanthile the sludge kept good settalbility during the sewage treatment process.