The innovative Osmotic Membrane Bioreactor (OMBR) for reuse of wastewater

2011 ◽  
Vol 63 (8) ◽  
pp. 1557-1565 ◽  
Author(s):  
E. R. Cornelissen ◽  
D. Harmsen ◽  
E. F. Beerendonk ◽  
J. J. Qin ◽  
H. Oo ◽  
...  

An innovative osmotic membrane bioreactor (OMBR) is currently under development for the reclamation of wastewater, which combines activated sludge treatment and forward osmosis (FO) membrane separation with a RO post-treatment. The research focus is FO membrane fouling and performance using different activated sludge investigated both at laboratory scale (membrane area of 112 cm2) and at on-site bench scale (flat sheet membrane area of 0.1m2). FO performance on laboratory-scale (i) increased with temperature due to a decrease in viscosity and (ii) was independent of the type of activated sludge. Draw solution leakage increased with temperature and varied for different activated sludge. FO performance on bench-scale (i) increased with osmotic driving force, (ii) depended on the membrane orientation due to internal concentration polarization and (iii) was invariant to feed flow decrease and air injection at the feed and draw side. Draw solution leakage could not be evaluated on bench-scale due to experimental limitation. Membrane fouling was not found on laboratory scale and bench-scale, however, partially reversible fouling was found on laboratory scale for FO membranes facing the draw solution. Economic assessment indicated a minimum flux of 15 L.m−2h−1 at 0.5M NaCl for OMBR-RO to be cost effective, depending on the FO membrane price.

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1098
Author(s):  
Khum Gurung ◽  
Morten Lykkegaard Christensen ◽  
Mika Sillanpää ◽  
Mohamed Chaker Ncibi ◽  
Mads Koustrup Jørgensen

The effects of reverse salt diffusion through a forward osmosis membrane were studied in a microfiltration osmotic membrane bioreactor. The reactor was used to treat and simultaneously concentrate nutrients from wastewater. The system was operated at different draw solution concentrations, leading to varying salinity conditions. A relatively low, yet stable forward osmosis flux was observed regardless of increasing draw solution conductivities from 10 to 50 mS cm−1. A substantial increase in sludge conductivity from 5.7 to 19.8 mS cm−1 was observed during the operation. Batch transmembrane pressure-step experiments showed a decline in sludge filtration properties with increasing salinity buildup in sludge due to increasing deflocculation and associated release of protein and carbohydrate fractions of extracellular polymeric substances. Mathematical simulations showed that accumulation of total dissolved solids could mainly be attributed to reverse flux of salts from the draw solution rather than by the enrichment of incoming nutrients when forward osmosis membrane’s salt permeability was high and water permeability low. Ideally, salt permeability below 0.010 L m−2 h−1 and effective water permeability above 0.13 L m−2 h−1 bar−1 are crucial to ensure enhanced nutrient enrichment and reduce sludge osmotic pressure, microbial inactivation, sludge deflocculation and membrane fouling.


2011 ◽  
Vol 63 (4) ◽  
pp. 733-740 ◽  
Author(s):  
E. Sahar ◽  
M. Ernst ◽  
M. Godehardt ◽  
A. Hein ◽  
J. Herr ◽  
...  

The potential of membrane bioreactor (MBR) systems to remove organic micropollutants was investigated at different scales, operational conditions, and locations. The effluent quality of the MBR system was compared with that of a plant combining conventional activated sludge (CAS) followed by ultrafiltration (UF). The MBR and CAS-UF systems were operated and tested in parallel. An MBR pilot plant in Israel was operated for over a year at a mixed liquor suspended solids (MLSS) range of 2.8–10.6 g/L. The MBR achieved removal rates comparable to those of a CAS-UF plant at the Tel-Aviv wastewater treatment plant (WWTP) for macrolide antibiotics such as roxythromycin, clarithromycin, and erythromycin and slightly higher removal rates than the CAS-UF for sulfonamides. A laboratory scale MBR unit in Berlin – at an MLSS of 6–9 g/L – showed better removal rates for macrolide antibiotics, trimethoprim, and 5-tolyltriazole compared to the CAS process of the Ruhleben sewage treatment plant (STP) in Berlin when both were fed with identical quality raw wastewater. The Berlin CAS exhibited significantly better benzotriazole removal and slightly better sulfamethoxazole and 4-tolyltriazole removal than its MBR counterpart. Pilot MBR tests (MLSS of 12 g/L) in Aachen, Germany, showed that operating flux significantly affected the resulting membrane fouling rate, but the removal rates of dissolved organic matter and of bisphenol A were not affected.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
S. Annop ◽  
P. Sridang ◽  
P. Chevakidagarn ◽  
K. Nopthavorn

The main objective was to compare the performances and the removal efficiencies of two biological treatment systems, a submerged membrane bioreactor (SMBR) and a simultaneous activated sludge (AS), for treating Palm Oil Mill Effluent (POME). Two lab scale units of SMBR and AS with a working volume of 24 L were operated under favorable biological conditions and minimized membrane fouling intensity. To achieve both carbonaceous and nitrogen removal, the cyclic air intermittent and dissolved oxygen control were performed into SMBR and AS with the influent flow rate about 16 L/d respectively. In terms of organic removal and membrane performance, the SMBR showed good removal efficiency to treat high strength wastewater with organic loading variation of POME. The average removal rates of TCOD, BOD, Turbidity, Color, Oil and Grease, NH3–N, TKN were 69±2, 76±2, 100±1, 37±21, 92±6, 67±4 and 75±10% respectively. Results pointed out the benefit of membranes retained totally the active compositions of biomass in each stage of development. The AS showed the limitation of sedimentation phase for sludge and oil separation. The characteristics of sludge in SMBR showed healthy floc formations and good settling after 240 h. The concentrations of COD and BOD in permeate were around 870±53 and 37±13 mg/L.


2021 ◽  
pp. 117869
Author(s):  
Xianzheng Zhu ◽  
Liven Wenhui Lee ◽  
Guangqing Song ◽  
Xian Zhang ◽  
Yue Gao ◽  
...  

2008 ◽  
Vol 57 (5) ◽  
pp. 773-779 ◽  
Author(s):  
Xianghua Wen ◽  
Pengzhe Sui ◽  
Xia Huang

In this study, ultrasound was applied to control membrane fouling development online in an anaerobic membrane bioreactor (AMBR). Experimental results showed that membrane fouling could be controlled effectively by ultrasound although membrane damage may occur under some operational conditions. Based upon the observation on the damaged membrane surface via SEM, two mechanisms causing membrane damage by exerting ultrasound are inferred as micro particle collide on the membrane surface and chemical interaction between membrane materials and hydroxyl radicals produced by acoustic cavitations. Not only membrane damage but also membrane fouling control and membrane fouling cleaning were resulted from these mechanisms. Properly selecting ultrasonic intensity and working time, and keeping a certain thickness of cake layer on membrane surface could be effective ways to protect membrane against damage.


2013 ◽  
Vol 641-642 ◽  
pp. 87-91 ◽  
Author(s):  
Zheng Hua Duan ◽  
Liu Ming Pan ◽  
Hua Wang ◽  
Ning Tao Li

To improve the efficiency of oily wastewater purification, a laboratory-scale anaerobic/anoxic/aerobic (A2O) membrane bioreactor was designed to treat the oily wastewater based on the conventional A2O activated sludge process and membrane separation technology, and the variation of bacterial community structure in the activated sludge of key reactors were investigated by PCR-DGGE (denaturing gradient gel electrophoresis). The result of Shannon diversity index comparing indicated that MBR seemed to be more constant than the A/0 system. Four sensitive dominant bacteria were verified in the treatment of oily wastewater. They were Uncultured Comamonadaceae bacterium, Hydrogenophaga sp., uncultured beta proteobacterium, and uncultured Thiobacillus sp. It suggested that PCR-DGGE can be used as an effective supplementary method for verifying cultural dominant microorganisms in activated sludge of oily wastewater.


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