Research On The Mechanism And Evaluation For Minimization Of Excess Sludge Production By Metabolism Uncoupling

Minimization of excess sludge production could be realized by metabolism uncoupling. The research on the effects of uncoupler on biomass yield in activated sludge systems was not very deep, and the way of evaluation for the effects of uncoupler on biomass yield is not found. Thus, 2, 4-dechlorophenol (DCP) as an uncounpler was added in activated system in this work, and the effects of DCP on biomass yield and correlative kinetics parameters were studied. The theory and method of identification and evaluation for fuzzy pattern was introduced to the field of minimization of excess sludge production. The reduction in the excess sludge production in the presence of heavy metal and uncoupler was studied in this work.In light of a newly developed theory of metabolism uncoupling, catabolism could be uncoupled with anabolism under particular conditions, thereby resulting in energy spilling and decreasing biomass yield. Uncoupler affected other parameters, such as rate of chemical oxygen demand (COD) removing, total value of oxygen uptaking and coupling coefficient of metabolism. Respective batch experiments which inhibitor and uncoupler were added were carried and datum was analyzed and contrasted. Method of identification and evaluation for fuzzy pattern was introduced to optimizing the concentration of uncoupler.With the concentration of DCP increasing, specific oxygen uptake rate (SOUR) increased and biomass yield decreased. The curve of the relative specific sludge growth rate (μ/μ0) and substrate removal rate (q/q0) varying with the concentration of DCP were discrepant. DCP ranging from 1 mg/L to 5 mg/L could effectively reduce the production of excess sludge. Uncoupling model was able to simulate the observed yield decreasing with the concentration of DCP increasing in this work. Method of identification and evaluation for fuzzy pattern can be introduced to optimizing the concentration of uncoupler. DCP ranging from 2 mg/L to 5 mg/L could effectively reduce the production of excess sludge;while Zn2+ ranging from 1 mg/L to 10 mg/L could not effectively reduce the production of excess sludge. The analysis demonstrated that energy spilling occurred in the presence of DCP, and that DCP was an effective uncoupler for reducing the production of excess activated sludge without affecting the microbial respiration activity.The effects of uncoupler and heavy metal on activated sludge were studied systematacially and deeply;a new method—identification and evaluation for fuzzy pattern—was introduced in this work.