The Study Of The Influence Factors Of Sludge Reduction In Sewage Treatment And The Establishment Of Mathematical Model

With the rapid development of economy,the continuous improvement of science and technology level,the sewage treatment and disposal capacity is constantly strengthened,the amount of sludge generated in wastewater treatment is constantly increasing,how to deal with the remaining sludge without causing secondary pollution to the environment,is an urgent problem for the sewage treatment industry to solve.Heating and alkali-hydrolysis pretreatment can reduce sludge volume by releasing sludge cell material,which is one of the sludge reduction methods widely applied and studied at present.This experiment took the residual sludge of pharmaceutical wastewater as the research object,and studied the influence of heating,alkali-hydrolysis and oxidation pretreatment on the effect of sludge cytolysis and reduction,as well as the influence of the mixture ratio of residual sludge after pretreatment on sludge reduction in the anaerobic digestion process.The pre-treatment experiment mainly compared the lysosis cracking effect of sludge under different conditions.From the analysis of the data,it can be concluded that: the higher the heating temperature,the better the lysosis effect of sludge;Similarly,the higher the PH of alkaline hydrolysis,the better the alkaline hydrolysis effect;However,for the oxidation of potassium ferrate,higher potassium ferrate dose did not make the sludge cytolysis rate higher.The above three pretreatment methods can reduce the SS value of sludge to a certain extent.Combined with response surface model method,it is concluded that the sludge dissolved cell rate and reduction rate of the largest optimal solution,namely,when the temperature is 85 ℃,PH 10.8,potassium ferrate dosing quantity for 3 g/g SS,3.5 hours stirring reaction,sludge dissolved cell rate is highest,54.36%;When the temperature is 92 ℃,PH value of11.8,potassium ferrate SS,mixing content is 7.02 mg/g 3.6 hours under the condition of reaction,the sludge reduction rate is maximum,31.86.The pretreated sludge was added into the anaerobic tank of UASB anaerobic reactor and pharmaceutical wastewater and sewage station at the mixing ratio of 20%,50% and 70%.It was observed that SV30 and MLSS of UASB and anaerobic sludge were reduced by about 10% after the addition of 20% pretreated sludge,and the amount and times of mud discharge were also reduced correspondingly.