Research On The Application Of The Self-forming Bio-dynamic Membrane Reactor In Disposing Municipal Sewage

The self-forming bio-dynamic membrane reactor (SFDMB) was equipped with plate membrane that was made of a 0.1mm nylon mesh as filter material instead of a micro-filtration membrane or an ultra-filtration membrane, and municipal sewage and artificial organic wastewater in high concentration were treated with the reactor. In the optimum designed device, the rules of the forming and regeneration of the bio-dynamic membrane were studied in the paper, furthermore, factors which had effects on those rules were also investigated. Compared with the effluents of static membrane, the bio-dynamic membrane showed desirable removal efficiencies by analyzing the treatment results of municipal sewage and artificial organic wastewater in high concentration. Then, biological phase of the system was observed, and it was found that the appearance of predations could have contributions to the reduction of membrane fouling and increases of the removals of the organic pollutants, but it was unfavorable to the removals of total phosphorus and turbidity. Finally, it also achieved the aim of treating sewage with less sludge production discharged by combining MBR and the technology of intensified function of these metazoans, such as predations.It was found that the effect of both sides lateral aeration was obviously better than that of unilateral aeration. In the system of both sides lateral aeration, compared with the increase of the regeneration velocity of the bio-dynamic membrane, the primary forming of the bio-dynamic membrane was faster than its regeneration. When HRT was about 5h, the average volume loading was 0.67kgCOD/m3.d, and water flux of membrane was 16.5L/m2.h, the SFDMB, in stabilization period, reached an average COD removal of 80% and the COD in the effluent could be kept under 40mg/L. And the average NH3-N removal efficiency was 93.1%, even reached 99.5% sometimes, and the concentration of NH3-N in the effluent were under 8mg/L, most times under 2mg/L. Furthermore, the reactor achieved a turbidity removal of 99% and the turbidity could be kept under 3NTU in the effluent. When there was some sludge production discharged, the removal of TP, which was greatly contributed by the sludge production, was about 74% and the TP was under 1mg/L in the effluent. Finally it was found that the present of Oligochaetes not only brought better characteristics of the sludge such as good settleabilily, but also minished the membrane fouling greatly, and did not affect the effluent quality. And most important of all, in the case of almost no sludge production discharged, MLSS could be kept nearly 4000mg/L in more than 40 days when Oligochaete was present, which meant that there was no sludge production in the process.