Development Of Membrane Bioreactor Research Articles

Composition Characterization and Transformation Mechanism of Dissolved Organic Matters in a Full-Scale Membrane Bioreactor Treating Co-Digestion Wastewater of Food Waste and Sewage Sludge

The membrane bioreactor (MBR) serves as the most widely used technology in anaerobic digestion wastewater treatment, but the composition and transformation of the dissolved organic matters (DOMs) are vague. This study focused on the composition characterization and transformation mechanism of DOMs in real co-digestion wastewater of food waste and sewage sludge from a full-scale MBR via molecular weight cut-off, 3D-EEM, FT-IR, and SPME-GC/MS. The results indicated that the co-digestion wastewater mainly comprised organics with molecular weight (MW) lower than 1 kDa and dominated by tryptophane-protein-like substances. The hydrolytic/acidogenic process improved the biodegradability with the conversion of high-MW organics into low-MW organics, while the two-stage A/O process possessed the highest contribution to the organic removal with the consumption of most DOMs. However, the deficient removal of refractory organics (MW < 5 kDa) in the ultrafiltration unit led to the residual DOMs in the effluent. The potential functional bacteria in the biological processes have also been identified and were principally affiliated with Proteobacteria and Firmicutes. These findings could help to advance the understanding of the co-digestion wastewater and provide fundamental information for the optimization and development of MBR in anaerobic digestion wastewater treatment.

Development of Membrane Bioreactor Using Polyvinylidene Difluoride Composites for Textile Dyeing Wastewater Treatment

Development of Membrane Bioreactor Using Polyvinylidene Difluoride Composites for Textile Dyeing Wastewater Treatment

Inhibition of biofouling in membrane bioreactor by metabolic uncoupler based on controlling microorganisms accumulation and quorum sensing signals secretion.

Biofouling is a limiting bottleneck in the development of membrane bioreactor (MBR) since the birth of this technology. Recently, the biofouling control strategy based on interfering with the bacterial quorum sensing (QS) system is highly desirable for biofouling control in MBR. In this study, three lab-scale parallel MBR systems were operated over 100 days to investigate the inhibitory effect of a metabolic uncoupler (3,3',4',5-tetrachlorosalicylanilide, TCS) on biofouling and the potential mechanism for biofouling control. Compared to the control MBR, the fouling cycle duration of MBR 2 with 100μg/L TCS extended over two times. The attached biomass on membrane in MBR 2 decreased over 50% at the end of each operating period, which indicated that the addition of TCS significantly mitigated microorganisms accumulation on membrane. The content of interspecies QS signal (autoinducer-2) and intraspecific QS signals (N-octanoyl-dl-homoserine lactone, C8-HSL) was reduced by the TCS, suggesting the secretion of QS signals in MBR were affected by uncoupler. Although the addition of TCS induced brief fluctuations of extracellular proteins and polysaccharides, microorganisms seemed to rapidly acclimatize to the presence of TCS and then the secretion of extracellular polymeric substances (EPS) was inhibited by 100μg/L TCS. The continuous operation of MBR was not be affected by the low-concentration uncoupler via the analysis of substrate removal and sludge growth. This study systematically evaluated the effect and inhibitory efficiency of TCS on biofouling, biomass accumulation, QS signals, EPS and treatment performances, demonstrating the feasibility of metabolic uncoupler for biofouling control in MBR.

Improvement of Operational Performance of MBR with the Emphasis on Enhanced N and P Removal by Modification in Design

Membrane bio-reactor (MBR) is an innovative and effective wastewater treatment process, which has much more extra advantages than other processes. However, membrane fouling and high operational/maintenance costs are always two important factors that restrict the development of MBR. In order to alleviate membrane fouling, larger aeration rate is usually used, which increases the operational cost and decrease N and P removal efficiencies of MBR. This paper summarizes the pilot scale experimental study on the improvement of operational performance of MBR by its design modification from one cell into three cells with micro-aeration,normal aeration and enhanced aeration conditions respectively with the package of fibrous bio-film carrier and PAC. As the result, the effluent water quality was improved significantly and membrane fouling was alleviated remarkably.

A Comparative Study of Aerobic Granule and Activated Sludge Based Dynamic Membrane Reactors for Wastewater Treatment

Dynamic membrane bioreactor (DMBR), as a new development of membrane bioreactor (MBR) technology, has attracted increasing attention recently. However, the effluent quality is usually affected by an incomplete rejection of sludge flocs and other suspended solids (SS) by the meshes. Herein, a novel aerobic granule dynamic membrane bioreactor (AGDMBR) is proposed. A comparison of the AGDMBR and DMBR systems was made in this study. According to the results, AGDMBR not only had higher NH4+ and turbidity removal, but also exhibited better anti-fouling capability than DMBR, implying a high potential of this technology for low-cost and efficient wastewater treatment.

Membrane bioreactors progress from the laboratory to full-scale use

This paper looks at the recent developments in membrane bioreactors and the reasons behind their transformation from an advanced laboratory technology into a commercially feasible process for full-scale use. A review of the trends in membrane costs and performance shows an approximate halving of the capital expenditure and an effective ten-fold reduction in the projected operating costs since 1992. The Kubota flat-sheet submerged membrane process is briefly introduced, and the results which are based on operating experience of pilot and full-scale effluent treatment plants are also given.