Investigation of Excess Biological Sludge Reduction in Sequencing Bach Reactor

Abstract

The ultimate disposal of excess sludge generated from activated sludge processes is one of the most challenging problems for wastewater treatment utilities. In this research, the two sequence batch reactors (SBR) used with cylindrical shape tank, net volume of 20 L and treatment capacity of 10 L per cycle. After reaching to steady state and stable situation in pilot running, the parameters of COD, MLSS, MLVSS, SVI, SOUR, residual ozone and yielding kinetics tested during 8 months. The results demonstrated that MLSS concentration increase a little after initially breakthrough due to feed ozone. COD removal efficiency reaches to 42 % at 25 mg/L ozone/g MLSS. The MLSS concentration also reduced considerably. In the other hand, Biomass production rate/g COD (Y) in 10 day cell retention time in without ozone dosage stage reach to 0.62 mg produced biomass. But, Y rate decreases by ozone dosage increment to part of sludge which reaches to 20 mg ozone/g MLSS of 1 L circulated sludge. Biomass production rate/g COD (Y) in 10 day cell retention time in without ozone dosage stage reach to 0.62 mg produced biomass. But, Y rate decreases with ozone dosage increment to part of sludge. And, we can reach to standard levels by10 day cell retention time in just feed 4.2 mg ozone/g MLSS to circulated sludge.