Study On Acrylic Fiber Wastewater Treatment In A New Sequencing Batch Biofilm Reactor Process And Coagulation Sedimentation

SBBR process (Sequencing Biofilm Batch Reactor) was a new process which has many virtues in the reactor on the base of SBR, it not only has the characteristics of sequencing batch technique but also the advantages of biofilm technology which change the activated sludge into biofilm with carrier.In this paper the real acrylic fiber wastewater was treated in SBBR which added the polyurethane foam for biofilm carrier. In the SBBR system the main factors such as anaerobic HRT, aerobic HRT, PH, C/N ratio had been researched; and the best experiment condition of the factors had been gained. Then the real acrylic fiber wastewater was pretreated and advanced treated by PAC coagulation sedimentation. The main conclusions were the following:(1) SBBR had a good removal efficiency , the removal rate of COD was higher than 60%,so it was obvious that biofilm resistance of the organic loading capacity is very strong.(2) As compared with the polyurethane foam, mixture of PVF-I carrier and polyurethane foam did not increase the removal rate of COD,while greatly increased the removal rate of NH3-N and the removal rate of TOC and TN slightly increased.(3) Through test analysis, the best parameters condition : when HRT was 24h, anaerobic HRT was 16h , aerobic HRT was 5h, DO concentration was 4.5mg/L, the removal rate of COD,TOC,TN was 69.7%,49.5%,55% respectively, also its DMAC and AN removal rate was almost 100%.(4) Observed by the microscope, microorganism form was quite abundant that came into being complex ecosystem consisted of bacterium, epiphyte, Protozoa and metazoan.(5) The results of PAC and PAM coagulation sedimentation to pretreat acrylic fiber wastewater indicated that pH was the first factors to the removal rate of COD, the second was PAC concentration, the third was mixing velocity, the last was PAM concentration. At the best parameters condition: when pH was 4.5, PAC concentration was 200 mg/L,mixing velocity was 175r/min,PAM concentration was 1.0 mg/L, the removal rate of COD, NH3-N, TOC,TN was 11.5%,2.5%,19.3%,9,9%, respectively, also its DMAC and AN removal rate was 23.5%,37.9%.(6) The results of PAC and PAM coagulation sedimentation to advanced treat acrylic fiber wastewater indicated that mixing velocity was the first factors to the removal rate of COD, the second was pH , the third was PAC concentration, the last was PAM concentration. At the best parameters condition : when pH was 3.5,PAC concentration was 650 mg/L,mixing velocity was 125r/min,PAM concentration was 1.4 mg/L, the removal rate of COD,NH3-N,TOC,TN was 28%,12%,18.8%,19.5%, respectively.