Ultrafiltration of activated sludge with ceramic membranes in a cross-flow membrane bioreactor process

2000 ◽  
Vol 41 (10-11) ◽  
pp. 243-250 ◽  
Author(s):  
X-j. Fan ◽  
V. Urbain ◽  
Y. Qian ◽  
J. Manem
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Ceramic Membrane ◽  
Treatment Plant ◽  
Cross Flow ◽  
Ceramic Membranes ◽  
Permeate Flux ◽  
Chemical Cleaning

A cross-flow membrane bioreactor (MBR) for raw municipal wastewater treatment, consisting of a suspended growth bioreactor and a ceramic membrane ultrafiltration unit, was run over a period of more than 300 days in a wastewater treatment plant (WWTP). Sludge Retention Times (SRT) of 20, 10 and 5 days, respectively, and Hydraulic Retention Times (HRT) of 15 and 7.5 hours were tested. Membrane fouling was found to be a function of SRT and permeate flux. Under an SRT of 20 days and flux of 71 l/m2\ · h at 30°C, the MBR was successfully run over 70 days without the need for chemical cleaning. However chemical cleaning had to be undertaken every 3–5 days at shorter sludge retention times (typically an SRT of five days and a flux of 143 l/m2\ · h at 30°C). In this study, fouling materials were removed efficiently through chemical cleaning, with an average permeablity recovery of 87±11%.

scholarly journals Diethylene Glycol-Assisted Organized TiO2 Nanostructures for Photocatalytic Wastewater Treatment Ceramic Membranes

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 750 ◽  
Author(s):  
Ahmad ◽  
Kim ◽  
Kim ◽  
Kim
Keyword(s):  
Wastewater Treatment ◽  
Diethylene Glycol ◽  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Membrane Surface ◽  
Ceramic Membranes ◽  
Tio2 Nanorods ◽  
Hydrolysis Rate ◽  
Capping Agent ◽  
Alumina Support

A high-performance photocatalytic ceramic membrane was developed by direct growth of a TiO2 structure on a macroporous alumina support using a hydrothermal method. The morphological nanostructure of TiO2 on the support was successfully controlled via the interaction between the TiO2 precursor and a capping agent, diethylene glycol (DEG). The growth of anatase TiO2 nanorods was observed both on the membrane surface and pore walls. The well-organized nanorods TiO2 reduced the perturbation of the alumina support, thus controlling the hydrolysis rate of the TiO2 precursor and reducing membrane fouling. However, a decrease in the amount of the DEG capping agent significantly reduced membrane permeability, owing to the formation of nonporous clusters of TiO2 on the support. Distribution of the organized TiO2 nanorods on the support was very effective for the improvement of the organic removal efficiency and antifouling under ultraviolet illumination. The TiO2 nanostructure associated with the reactive crystalline phase, rather than the amount of layered TiO2 formed on the support, which was found to be the key to controlling photocatalytic membrane reactivity. These experimental findings would provide a new approach for the development of efficacious photocatalytic membranes with improved performance for wastewater treatment.

scholarly journals Optimization of In Situ Backwashing Frequency for Stable Operation of Anaerobic Ceramic Membrane Bioreactor

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 545 ◽  
Author(s):  
Rathmalgodage Thejani Nilusha ◽  
Tuo Wang ◽  
Hongyan Wang ◽  
Dawei Yu ◽  
Junya Zhang ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Ceramic Membrane ◽  
Pure Water ◽  
Ex Situ ◽  
Stable Operation ◽  
Chemical Cleaning ◽  
Cake Layer

The cost-effective and stable operation of an anaerobic ceramic membrane bioreactor (AnCMBR) depends on operational strategies to minimize membrane fouling. A novel strategy for backwashing, filtration and relaxation was optimized for stable operation of a side stream tubular AnCMBR treating domestic wastewater at the ambient temperature. Two in situ backwashing schemes (once a day at 60 s/day, and twice a day at 60 s × 2/day) maintaining 55 min filtration and 5 min relaxation as a constant were compared. A flux level over 70% of the initial membrane flux was stabilized by in situ permeate backwashing irrespective of its frequency. The in situ backwashing by permeate once a day was better for energy saving, stable membrane filtration and less permeate consumption. Ex situ chemical cleaning after 60 days’ operation was carried out using pure water, sodium hypochlorite (NaOCl), and citric acid as the order. The dominant cake layer was effectively reduced by in situ backwashing, and the major organic foulants were fulvic acid-like substances and humic acid-like substances. Proteobacteria, Firmucutes, Epsilonbacteria and Bacteroides were the major microbes attached to the ceramic membrane fouling layer which were effectively removed by NaOCl.

scholarly journals LCA of a Membrane Bioreactor Compared to Activated Sludge System for Municipal Wastewater Treatment

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 421
Author(s):  
Dimitra C. Banti ◽  
Michail Tsangas ◽  
Petros Samaras ◽  
Antonis Zorpas
Keyword(s):  
Wastewater Treatment ◽  
Life Cycle ◽  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Real Data ◽  
Municipal Wastewater Treatment ◽  
Conventional Activated Sludge

Membrane bioreactor (MBR) systems are connected to several advantages compared to the conventional activated sludge (CAS) units. This work aims to the examination of the life cycle environmental impact of an MBR against a CAS unit when treating municipal wastewater with similar influent loading (BOD = 400 mg/L) and giving similar high-quality effluent (BOD < 5 mg/L). The MBR unit contained a denitrification, an aeration and a membrane tank, whereas the CAS unit included an equalization, a denitrification, a nitrification, a sedimentation, a mixing, a flocculation tank and a drum filter. Several impact categories factors were calculated by implementing the Life Cycle Assessment (LCA) methodology, including acidification potential, eutrophication potential, global warming potential (GWP), ozone depletion potential and photochemical ozone creation potential of the plants throughout their life cycle. Real data from two wastewater treatment plants were used. The research focused on two parameters which constitute the main differences between the two treatment plants: The excess sludge removal life cycle contribution—where GWPMBR = 0.50 kg CO2-eq*FU−1 and GWPCAS = 2.67 kg CO2-eq*FU−1 without sludge removal—and the wastewater treatment plant life cycle contribution—where GWPMBR = 0.002 kg CO2-eq*FU−1 and GWPCAS = 0.14 kg CO2-eq*FU−1 without land area contribution. Finally, in all the examined cases the environmental superiority of the MBR process was found.

Performance of membrane bioreactor combined with pre-coagulation/sedimentation

2004 ◽  
Vol 4 (1) ◽  
pp. 143-149 ◽  
Author(s):  
T. Itonaga ◽  
Y. Watanabe
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Suspended Solids ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Term Operation ◽  
Made In

This paper deals with the performance of a hybrid membrane bioreactor (MBR) combined with pre-coagulation/sedimentation. Primary clarifier effluent in a municipal wastewater treatment plant was fed into the hybrid MBR to investigate its performance during long-term operation. Pre-coagulation/sedimentation process efficiently removed the suspended solids including organic matter and phosphorus. Comparison of the hybrid MBR and conventional MBR was made in terms of the permeate quality and membrane fouling. As the organic loading to the MBR was significantly reduced by the pre-coagulation/sedimentation, production and accumulation of extracellular polymeric substances (EPS) may be limited. Therefore, the mixed liquor viscosity in the hybrid MBR was much lower than that in the conventional MBR. These effect caused by pre-coagulation/sedimentation brought a remarkable improvement in both permeate quality and membrane permeability.

Modelling and simulation of filtration performance in membrane bioreactor systems for municipal wastewater treatment

2003 ◽  
Vol 3 (5-6) ◽  
pp. 267-273 ◽  
Author(s):  
T. Wintgens ◽  
J. Rosen ◽  
T. Melin ◽  
C. Brepols ◽  
K. Drensla ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Transfer Model ◽  
Municipal Wastewater Treatment ◽  
Permeability Evolution ◽  
Filtration Performance ◽  
Cake Layer ◽  
Filtration Unit

The paper outlines a model of the filtration performance of submerged capillary microfiltration modules in membrane bioreactor applications for wastewater treatment. The model was implemented for process simulation and calibrated by using operating data of the full-scale municipal wastewater treatment plant Rödingen, Germany, operated by Erft River Association (Erftverband), which is equipped with activated sludge treatment and microfiltration units for biomass retention. Mathematically recordable foundations of filtration resistances, such as cake layer forming and fouling, are presented along with a mass transfer model, describing the concentration polarisation on the feed-side and its dependence on a multiphase flow regime. The model simulates the long-term decrease in permeability of the membranes and outlines the influence of main operating parameters on flux performance. After parameter fitting for one filtration unit, the permeability evolution for a second unit could be also calculated.

scholarly journals Microcoagulation improved the performance of the UF–RO system treating the effluent from a coastal municipal wastewater treatment plant: a pilot-scale study

2021 ◽  
Author(s):  
Tong Yu ◽  
Chenlu Xu ◽  
Feng Chen ◽  
Haoshuai Yin ◽  
Hao Sun ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Contaminant Removal ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plant ◽  
Ro Membrane

Abstract Microcoagulation has recently been considered as a promising pretreatment for an ultrafiltration (UF) process from numerous studies. To investigate the effects of microcoagulation on the performance of the UF–reverse osmosis (RO) system treating wastewater with high and fluctuant salinity, different dosages of coagulant (poly-aluminum chloride) were added prior to the UF unit in a pilot-scale UF–RO system for a 10-week period operation. Microcoagulation obviously improved the contaminant removal and cleaning efficiencies, including water backwash, chemical enhanced backwash and cleaning in place processes. Organic fouling was dominated during the initial stage of the RO membrane fouling. The microbial communities of water samples and foulant on the RO membrane were similar to those of seawater and foulant on the RO membranes from seawater RO plants. The microbial community of the foulant on the membrane was similar to that of UF permeate and RO concentrate. These results demonstrated that microcoagulation could improve the performance of the UF–RO system treating the effluent with high and fluctuant salinity from a coastal municipal wastewater treatment plant.

scholarly journals Enhanced Removal of Organic Pollutants and Reactive Dye in Polyethersulfone Submerged Membrane Bioreactor (PES-SMBR) for Textile Wastewater

2021 ◽  
Vol 16 (1) ◽  
pp. 329-341
Author(s):  
Tukaram P. Chavan ◽  
Ganpat B. More ◽  
Sanjaykumar R. Thorat
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Textile Wastewater ◽  
Pilot Scale ◽  
Reactive Dye ◽  
Hollow Fibre ◽  
Flow Mode ◽  
Permeate Flux ◽  
Chemical Cleaning ◽  
Submerged Membrane Bioreactor

The present investigation was carried out to assess the operation of a pilot-scale submerged membrane bioreactor (SMBR) for the treatment of reactive dye and textile wastewater. The operation of SMBR model was conducted by using a polyethersulfone (PES) hollow fibre membrane with continuous flow mode at different HRTs at 8, 6 and 4 h, for 90 days. During the entire operation, the average permeate flux, TMP, F/M ratio and OLR was found to be 19 (L/m²/h), 2.6 (psi), 0.10 (g BOD/(g MLSS•d) and 0.89 (kg BOD/m³.d), respectively. The variations in the permeate flux, TMP, F/M ratio and OLR have not adversely effects on the operation of the SMBR model. Throughout the entire operation, despite the TP, TDS and conductivity, the high amount of COD (82%), BOD (86%), NO3-N (79%), TSS (98%), turbidity (97%) and colour (79%), removal was achieved. The permeate flux was declined by membrane fouling and it was recovered by chemical cleaning as well as regular backwashing during the entire operation. The results obtained from the study concluded that the hollow fibre ultrafiltration polyethersulfone (PES) membrane shows good performance while treating textile wastewater along with reactive dye solution.

scholarly journals UV and bacteriophages as a chemical-free approach for cleaning membranes from anaerobic bioreactors

2020 ◽  
Author(s):  
Giantommaso Scarascia ◽  
Luca Fortunato ◽  
Yevhen Myshkevych ◽  
Hong Cheng ◽  
TorOve Leiknes ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Combined Treatment ◽  
Chemical Cleaning ◽  
High Quality ◽  
Anaerobic Membrane Bioreactor ◽  
Membrane Biofouling ◽  
Uv C

ABSTRACTAnaerobic membrane bioreactor (AnMBR) for wastewater treatment has attracted much interest due to its efficacy in providing high quality effluent with minimal energy costs. However, membrane biofouling represents the main bottleneck for AnMBR because it diminishes flux and necessitates frequent replacement of membranes. In this study, we assessed the feasibility of combining bacteriophages and UV-C irradiation to provide a chemical-free approach to remove biofoulants on the membrane. The combination of bacteriophage and UV-C resulted in better log cells removal and twice higher extracellular polymeric substance (EPS) concentration reduction in mature biofoulants compared to UV-C. A reduction in the relative abundance of Acinetobacter spp. and selected gram-positive bacteria associated with the membrane biofilm was also achieved by the new cleaning approach. Microscopic analysis further revealed the formation of cavities in the biofilm due to bacteriophages and UV-C irradiation, which would be beneficial to maintain water flux through the membrane. When the combined treatment was further compared with the common chemical cleaning procedure, a similar reduction on the cell numbers was observed (1.4 log). However, combined treatment was less effective in removing EPS compared with chemical cleaning. These results suggest that the combination of UV-C and bacteriophage have an additive effect in biofouling reduction, representing a potential chemical-free method to remove reversible biofoulants on membrane fitted in an anaerobic membrane bioreactor.SIGNIFICANCEAnaerobic membrane bioreactors can achieve high quality effluent with a reduced energy consumption. However, biofouling represents the main bottleneck for membrane filtration efficiency. Biofouling is commonly reduced through chemical treatment. These agents are often detrimental for the environment and health safety due to the formation of toxic byproducts. Therefore, we present a new approach, based on the additive antifouling action of bacteriophages infection and UV-C irradiation, to reduce anaerobic membrane biofouling. This new strategy could potentially delay the occurrence of membrane fouling by removing the reversible fouling layers on membranes, in turn reducing the frequencies and amount of chemicals needed throughout the course of wastewater treatment.

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