Internal Circulation Membrane Bioreactor And The Study On Its Application In The Wastewater Treatment For Reuse

The study focused on the shortage and low reutilization rate of water resources inour country, developed a novel membrane bioreactor——Internal CirculationMembrane Bioreactor (ICMBR). After the reactor was set up, ICMBR was operatedfor 5 monthes using real wastewater from China Resources Breweries Co., Ltd. asinfluent;the start-up, performance, sludge characteristics and membrane fouling inICMBR were reseached.The principle of ICMBR is based on the Internal Circulation Reactor. Throughfixing hollow fiber membrane module and aeration pipe in the second reaction sectionof IC, ICMBR formed a compact process of IC and MBR;its working characteristic issimilar with the series of Upflow Anaerobic Sludge Blanket and MembraneBioreactor. Moreover, ICMBR attained internal circulation from gas upflow, therefore,it successfully realized simutaneous removal of organic pollutant and nitrogen in onereactor, with 93% and 92% removal efficiency of COD and TN respectively. Sincesignificantly decreased aeration and dispensed with the power for internal circulation,ICMBR could save 50% energy comparing with the current MBR.During the operation of ICMBR, there formed granular sludge with goodperformance in the anaerobic section. The granulation process was characterized bythree phases, namely acclimation, granulation and maturation. At the end of theoperation, the Specific Methanogenic Activity and Sludge Volume Index of thegranular sludge reached 1.52gCOD₍CH_4/gVSS·d and 12.5mL/gSS respectively;and thebioparticle have a higher strength, abration experiment showed that the abration ratecoefficient of the bioparticle is 0.152d^-1. During maturation phase, bioparticle sizekept homeostasis, with medium diameters of 2.51mm;the concentration of MLVSS is15.2g/L in anaerobic section;the biomass synthesis was low, with the maxiumspecific growth rate of 0.018d^-1, therefore, the sludge wasn't discharged.ICMBR worked in the mode of continuous influent and intermittent effluent. Thechange of membrane flux was characterized by two phases of rapid decline andstabilization, membrane fouling was effectively restrained by aeration and workingmode of intermittent effluent. When the flux stabilized at 10L/m²Â·h finally, the changeof aeration and MLVSS concentration hadn't significant influence on it.Reviewed from the whole experiment results, ICMBR has a high removalefficiency of organic pollutant and nitrogen;and is easy to operate, Therefore,ICMBR has a good prospect for equipment development. However, the relationbetween gas production and internal circulation flow, the separation of biogas from air,and the microecology of granular sludge are the problems to further research.