Study Of Domestic Sewage Concentration Using Flocculation-dynamic Membrane

Water pollution is becoming highlighted at this stage in China，as for waste waterrecycling and resource recovery is requirement of realizing sustainable development ofwater. At present most municipal sewage treatment plants use the traditional process ofaerobic biological treatment，which transfers the organic pollutants in water into CO2. Thequality of the treated water is good, but it wastes a lot of power. Carrying out the reuse ofresources in urban sewage treatment can alleviate the increasingly serious energy crisistoday. Anaerobic technology as a way of the traditional and economical treatment can getenergy from sewage. It is a sustainable water treatment process. However, the smallconcentration of organic matter in sewage makes it difficult to meet the requirement ofanaerobic treatment. Therefore, it’s necessary for pre-separation of organic matter insewage to achieve an effective concentration of organic matter and make an energyrecovery.In the research we discussed a novel sewage treatment route and we designed aflocculation-dynamic membrane reactor. Flocculation as the pretreatment of the dynamicmembrane, sewage and the combination of dynamic membrane separation technology forsewage concentration treatment directly explore the feasibility of a preliminary. The resultsshow that: the optimized coagulants were PAC and diatomite and the optimum dosage were60mg/L and30mg/L. Cloth621was the best support media because of its high strength,low resistance, and the better capacity of holding back. The dynamic membrane wasquickly formed, therefore the effluent quality was good. The COD of concentrated sewagereach5180.7mg/L, the sewage was concentrated by13.47times. The concentration of SSwas5.08mg/L.54%of the COD was concentrated in the reactor,25%ran off with theeffluent,20%as CO2was lost into the atmosphere by biological effect. The suctionpressure is stable at about80kPa finally. The volume average particle size of theconcentrated liquid was D[4,3]=35.228μ m.99.5%of the dynamic membrane resistancewas from the cake layer, was from the gel layer. Using a soft brush to wash the dynamicmembrane surface, can make the film substrate recovery to the initial state.