Study On Submerged Membrane Reactor Of A/O Process For The Treatment Of Domestic Wastewater And Project Application

Currently, domestic wastewater has become a major factor affecting the quality of urban water environment. Shortage of water resources and water pollution are the limitation of the sustainable development of modern society. So it is becoming very significant to alleviate water resources crisis that we can adopt some sewage treatment technologies to treat and recycle sewage. But at present, the rate of domestic wastewater treatment and the rate of domestic wastewater recycling are very low, it is profound significant to engage in the study of waste recycling.Membrane bioreactor is a new technic, which makes use of membrane's separation function and activated sludge treatment. As a new technic, there is much space left for development.On the basis of existed nitrogen treatment processes, an anoxic-aerobic flat-sheet membrane bioreactor (A/O-MBR) was chose to treat the low-strength domestic wastewater. In this paper, low-strength domestic wastewater was treated using A/O-MBR and made the effluent quality reached "the Water quality standard for urban miscellaneous water consumption" promulgated by the ministry of construction. Experiments were carried out to investigate the operation effciency, the characteristic of sludge, and law of sludge growth. By optimizing the operation condition, a reference and basis of design was provided for project practice.In the case of no discharge of excess sludge, the average concentration of effluent's COD_Cr, NH₄⁺-N, SS were 16.2 mg/L, 1.76 mg/L, 7.82 mg/L, with average removal efficiencies of 86.2%, 95.5%, 83.38% respectively. It meets the demand of wastewater reuse, reached "the water quality standard for urban miscellaneous water consumption". It is feasible to treat low-strength domestic wastewater using the technics.A/O-MBR system had good denitrification performance by the study of relationship between C/N ratio and denitrification efficiency. In this system, it is considerate that chemical phosphorus removal method should be used to intensify system phosphores removal effect.Based on the experiment results, the A/O-MBR system was used in a domestic sewage treatment project. The rusults show that this process has a lot of merits, assuring high quality treated water, reducing investment finance, managing simply and automatically. Also it gives visible economic and social benefit. Therefore the treatment process of A/O-flat sheet membrane bioreactor in domestic wastewater has wide application prospect.