Effect Of Dosing PAC And Fe³⁺ On The Sludge Mixed Liquor Characteristics And Microorganism In A/O-MBR

The research explains the effect of dosing PAC and Fe³⁺ on the sludge mixed liquor characteristics and microorganism in A/O-MBR,from the view of mechanism,the interaction between the physical and chemical properities of the mixture,microorganism.Test was duivided into three stages: the first stage was the beaker test, the optimal dosage of PAC and Fe³⁺ were determined by this;the second stage dosing the quantification activated carbon and then for long-term reactor operation,the mixture properities and microbial community were analyzed;the third stage dosing the quantification Fe³⁺ and then for long-term reactor operation;same research project as phaseⅡ.Test showed that the powered activated carbon played the role of frame in activated sludge and improved the sludge floc resistance to stress,so that the gel layer of the floc was relatively loose and high porosity;Fe³⁺ played influence on the nature of mixture and microbial mainly through the role of electricity. By beaker test,determined the optimal dosage of PAC and Fe³⁺ were 2g/L and 1.2mmol/L. Through the research on the activity indicators of sludge of VSS/SS,SOUR and dehydrogenase found that,the activity of sludge of the biological iron law was lower than the carbon sludge,by the sludge on the metabolities od EPS and SMP have found that on the stage of dosing PAC,microbial metabolites and other nature of the sludge showed better correlation , description that Fe³⁺ inhibited the activity of certain microorganisms. The test carried on the extraction of bacteria DNA and PCR-DGGE analysis for the two stage sludge,the bands were recoveried and sequenced, and sequencing results were analysied.