scholarly journals Nutrients Enrichment and Process Repercussions in Hybrid Microfiltration Osmotic Membrane Bioreactor: A Guideline for Forward Osmosis Development Based on Lab-Scale Experience

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1098
Author(s):  
Khum Gurung ◽  
Morten Lykkegaard Christensen ◽  
Mika Sillanpää ◽  
Mohamed Chaker Ncibi ◽  
Mads Koustrup Jørgensen
Keyword(s):  
Water Permeability ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Forward Osmosis ◽  
Microbial Inactivation ◽  
Transmembrane Pressure ◽  
Pressure Step ◽  
Draw Solution ◽  
Osmotic Membrane Bioreactor

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.

Electrically enhanced MBR system for total nutrient removal in remote northern applications

2012 ◽  
Vol 65 (4) ◽  
pp. 737-742 ◽  
Author(s):  
V. Wei ◽  
M. Elektorowicz ◽  
J. A. Oleszkiewicz
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Climatic Conditions ◽  
Transmembrane Pressure ◽  
Treatment Technology ◽  
Electrically Enhanced ◽  
P Removal

Thousands of sparsely populated communities scatter in the remote areas of northern Canada. It is economically preferable to adopt the decentralized systems to treat the domestic wastewater because of the vast human inhabitant distribution and cold climatic conditions. Electro-technologies such as electrofiltration, elctrofloatation, electrocoagulation and electrokinetic separation have been applied in water and conventional wastewater treatment for decades due to the minimum requirements of chemicals as well as ease of operation. The membrane bioreactor (MBR) is gaining popularity in recent years as an alternative water/wastewater treatment technology. However, few studies have been conducted to hyphenate these two technologies. The purpose of this work is to design a novel electrically enhanced membrane bioreactor (EMBR) as an alternative decentralized wastewater treatment system with improved nutrient removal and reduced membrane fouling. Two identical submerged membranes (GE ZW-1 hollow fiber module) were used for the experiment, with one as a control. The EMBR and control MBR were operated for 4 months at room temperature (20 ± 2 °C) with synthetic feed and 2 months at 10 °C with real sewage. The following results were observed: (1) the transmembrane pressure (TMP) increased significantly more slowly in the EMBR and the interval between the cleaning cycles of the EMBR increased at least twice; (2) the dissolved chemical oxygen demand (COD) or total organic carbon (TOC) in the EMBR biomass was reduced from 30 to 51%, correspondingly, concentrations of the extracellular polymeric substances (EPS), the major suspicious membrane foulants, decreased by 26–46% in the EMBR; (3) both control and EMBR removed >99% of ammonium-N and >95% of dissolved COD, in addition, ortho-P removal in the EMBR was >90%, compared with 47–61% of ortho-P removal in the MBR; and (4) the advantage of the EMBR over the conventional MBR in terms of membrane fouling retardation and phosphorus removal was further demonstrated at an operating temperature of 10 °C when fed with real sewage. The EMBR system has the potential for highly automated control and minimal maintenance, which is particularly suitable for remote northern applications.

scholarly journals Optimization of Operating Conditions in Forward Osmosis for Osmotic Membrane Bioreactor

2009 ◽  
Vol 3 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Jian-Jun Qin ◽  
Maung Htun Oo ◽  
Guihe Tao ◽  
E. R. Cornelissen ◽  
C. J. Ruiken ◽  
...  
Keyword(s):  
Flow Pattern ◽  
Membrane Bioreactor ◽  
Concentration Polarization ◽  
Forward Osmosis ◽  
Operating Conditions ◽  
Solute Diffusion ◽  
External Concentration ◽  
Selective Layer ◽  
Draw Solution ◽  
Osmotic Membrane Bioreactor

Objective of this study was to conduct a baseline study of osmotic membrane bioreactor (OMBR) - optimization of operating conditions in forward osmosis (FO). Experiments were conducted with an FO pilot system. Tap water was used as the feed and NaCl and MgSO4 solutions were used as draw solution. Effects of various operating conditions on flux have been investigated. In addition, pure water permeability of the FO membrane was tested. It was observed that the plant operation could be stablized within 1 h. When the membrane selective layer faced to the feed, a flux of 6.3 lm-2h-1 (LMH) was achieved at 24 atm osmotic pressure and 25 °C and effects of feed velocity and air velocity on flux were not siganificant under the testing conditions due to low external concentration polarization (ECP). However, when the selective layer faced to the draw solution, the flux was enhanced by 64% due to much reduced internal concentration polarization (ICP), the flux sharply increased with an increase in velocity of the draw solution in the laminar flow pattern range due to a countable effect of dilutive external concentration polarization (DECP) and leveled off after the flow pattern became turbulent. NaCl performed much higher efficiency than MgSO4 as an osmotic agent due to a greater solute diffusion coefficient of NaCl.

Preliminary study of osmotic membrane bioreactor: effects of draw solution on water flux and air scouring on fouling

2010 ◽  
Vol 62 (6) ◽  
pp. 1353-1360 ◽  
Author(s):  
Jian-Jun Qin ◽  
Kiran A. Kekre ◽  
Maung H. Oo ◽  
Guihe Tao ◽  
Chee L. Lay ◽  
...  
Keyword(s):  
Osmotic Pressure ◽  
Membrane Bioreactor ◽  
Water Flux ◽  
Forward Osmosis ◽  
Operating Conditions ◽  
Draw Solution ◽  
Membrane Flux ◽  
Osmotic Membrane Bioreactor ◽  
Flux Decline ◽  
Preliminary Study

Preliminary study on a novel osmotic membrane bioreactor (OMBR) was explored. Objective of this study was to investigate the effects of draw solution on membrane flux and air scouring at the feed side on fouling tendency in a pilot OMBR system composing the anoxic/aerobic and forward osmosis (FO) processes. Domestic sewage was the raw feed, FO membrane from HTI and NaCl/MgSO4 draw solutions were used in the experiments. Fluxes of 3 l/m2/h (LMH) and 7.2 LMH were achieved at osmotic pressure of 5 and 22.4 atm, respectively. No significant flux decline was observed at 3 LMH over 190 h and at 7.2 LMH over 150 h when air scouring was provided at the feed side of the membrane. However, without air scouring, the flux at 22.4 atm osmotic pressure declined by 30% after 195 h and then levelled off. The potential advantages of the fouling reversibility with air scouring under the operating conditions of the pilot OMBR and better water quality in OMBR over the conventional MBR were preliminarily demonstrated.

scholarly journals Mechanism of Membrane Fouling Control by HMBR: Effect of Microbial Community on EPS

2020 ◽  
Vol 17 (5) ◽  
pp. 1681
Author(s):  
Qiang Liu ◽  
Ying Yao ◽  
Delan Xu
Keyword(s):  
Microbial Community ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Microbial Community Composition ◽  
Domestic Wastewater ◽  
Control Group ◽  
Transmembrane Pressure ◽  
Fouling Control ◽  
Cake Layer

A hybrid membrane bioreactor (HMBR) employing activated sludge and biofilm simultaneously is proved to represent a good performance on membrane fouling control compared to conventional membrane bioreactor (CMBR) by reducing extracellular polymeric substances (EPS), especially bound EPS (B-EPS). In order to better understand the mechanism of membrane fouling control by the HMBR in regard of microbial community composition, a pilot scale HMBR operated to treat domestic wastewater for six months, and a CMBR operated at the same time as control group. Results showed that HMBR can effectively control membrane fouling. When transmembrane pressure reached 0.1 MPa, the membrane module in the HMBR operated for about 26.7% longer than that in the CMBR. In the HMBR, the quantity of EPS was significantly lower than that in the CMBR. In this paper, soluble EPS was also found to have a close relationship with cake layer resistance. The species richness and diversity in the HMBR were higher than those in the CMBR, and a certain difference between the compositions of microbial communities in the two reactors was confirmed. Therefore, the difference in microbial community compositions may be the direct reason why EPS in the HMBR was lower than that in the CMBR.

scholarly journals Characterization of the Fouling Layer on the Membrane Surface in a Membrane Bioreactor: Evolution of the Foulants’ Composition and Aggregation Ability

Membranes ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 85 ◽  
Author(s):  
Linlin Yan ◽  
Ruixue Li ◽  
Yu Song ◽  
Yanping Jia ◽  
Zheng Li ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Membrane Surface ◽  
Extracellular Dna ◽  
Transmembrane Pressure ◽  
Average Roughness ◽  
Three Stages ◽  
Fast Rise

In this study, the characteristics of membrane foulants were analyzed with regard to morphology, composition, and aggregation ability during the three stages of transmembrane pressure (TMP) development (fast–slow–fast rise in TMP) in a steady operational membrane bioreactor (MBR). The results obtained show that the fouling layer at the slow TMP-increase stage possessed a higher average roughness (71.27 nm) and increased fractal dimension (2.33), which resulted in a low membrane fouling rate (0.87 kPa/d). A higher extracellular DNA (eDNA) proportion (26.12%) in the extracellular polymeric substances (EPS) resulted in both higher zeta potential (-23.3 mV) and higher hydrophobicity (82.3%) for initial foulants, which induced and increased the protein proportion in the subsequent fouling layer (74.11%). Furthermore, the main composition of the EPS shifted from protein toward polysaccharide dominance in the final fouling layer. The aggregation test confirmed that eDNA was essential for foulant aggregation in the initial fouling layer, whereas ion interaction significantly affected foulant aggregation in the final fouling layer.

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 ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Membrane Separation ◽  
Economic Assessment ◽  
Laboratory Scale ◽  
Membrane Area ◽  
Bench Scale ◽  
Draw Solution ◽  
Osmotic Membrane Bioreactor

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.

Anaerobic biodegradation and decolorization of a refractory acid dye by a forward osmosis membrane bioreactor

2018 ◽  
Vol 4 (2) ◽  
pp. 272-280 ◽  
Author(s):  
Fang Li ◽  
Qin Xia ◽  
Yingying Gao ◽  
Qianxun Cheng ◽  
Lián Ding ◽  
...  
Keyword(s):  
Membrane Bioreactor ◽  
Forward Osmosis ◽  
Anaerobic Biodegradation ◽  
Acid Dye ◽  
Osmotic Membrane Bioreactor

In this study, the feasibility of utilizing an anaerobic osmotic membrane bioreactor (OMBR) for the treatment of a refractory acid dye, Lanaset red G.GR, is demonstrated.

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