Studies On Treatment Of Refractory Wastewater In The Integrated Aerobic Membrane Bioreactor

By theatrical analysis, this paper offers such opinion that membrane bioreactor (MBR) can treat refractory wastewater efficiently and on that base, experiments were conducted because of complexity of the refractory organic substances, the experimental study of treating ordinary organic wastewater was conducted firstly, which offers references and comparisons for the experiments of treating refractory wastewater in MBR. A primary study on the properties of the activated sludge was also conducted at the same time the results show that:1 -When amylum wastewater was treated in the MBR under the condition of pH=7~8,T=15-29 ℃,HRT=4~13h and COD in(COD in the influent) =200~500mg/L,CODou(COD in the effluent)was lower than 60mg/L,the average was 26.6mg/L,the average removal efficiency of the MBR was 93.7%;when Polyvinyl Acetate (PVA) wastewater was treated under the condition of pH=7~ 8,T=15~29℃,HRT=10~20h and CODin= 100~600mg/L,CODouwas lower than 40 mg/L,the average was 26.6mg/L, the average removal efficiency of the MBR was 90.7%;which show the feasibility to treat the refractory wastewater with aerated MBR process.2.By analysis of the data obtained from the experiments, the calculated kinetics parameters of the two kinds of wastewater treated in MBR is: Yg =0.3281kgVSS/kgCOD, Kd=0.028d-1, vmax=6.95 kgCOD/(kgVSS-d), Ks = 2965.6 mg/L; PVA wastewater: Yg =0.3844kgVSS/kgCOD, Kd =0.01d-1', vmax =0.66kgCOD/(kgVSS-d), Ks = 507.4mg/L. The vmax of the PVA wastewater is only a tenth of that of amylum wastewater; treating PVA wastewater in MBR could get good effect.3. During the experiments of treating the PVA wastewater, the shortest solids retention time is 20.8d,the optimal solids retention time is40~80d,which can be realized perfectly in the MBR.4.1t is feasible to treat PVA wastewater in MBR, which can realized in two ways: the organic substances are retained within the reactor to be degraded by microbiology thoroughly, and the long-generation-time microbiology was retained within the reactor, they augment the biodegradation ofthe refractory organic substances.5 .Sludge in the MBR used in the experiments have such characteristics as high concentration high activity, powerful nitrifying ability, rich microbiological species.