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.

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 State-of-the-Art Ceramic Membranes for Oily Wastewater Treatment: Modification and Application

Membranes ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 888
Author(s):  
Mingliang Chen ◽  
Sebastiaan G. J. Heijman ◽  
Luuk C. Rietveld
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Ceramic Membrane ◽  
Sol Gel ◽  
Ceramic Membranes ◽  
Oily Wastewater ◽  
Membrane Modification ◽  
Flux Enhancement ◽  
Oily Wastewater Treatment

Membrane filtration is considered to be one of the most promising methods for oily wastewater treatment. Because of their hydrophilic surface, ceramic membranes show less fouling compared with their polymeric counterparts. Membrane fouling, however, is an inevitable phenomenon in the filtration process, leading to higher energy consumption and a shorter lifetime of the membrane. It is therefore important to improve the fouling resistance of the ceramic membranes in oily wastewater treatment. In this review, we first focus on the various methods used for ceramic membrane modification, aiming for application in oily wastewater. Then, the performance of the modified ceramic membranes is discussed and compared. We found that, besides the traditional sol-gel and dip-coating methods, atomic layer deposition is promising for ceramic membrane modification in terms of the control of layer thickness, and pore size tuning. Enhanced surface hydrophilicity and surface charge are two of the most used strategies to improve the performance of ceramic membranes for oily wastewater treatment. Nano-sized metal oxides such as TiO2, ZrO2 and Fe2O3 and graphene oxide are considered to be the potential candidates for ceramic membrane modification for flux enhancement and fouling alleviation. The passive antifouling ceramic membranes, e.g., photocatalytic and electrified ceramic membranes, have shown some potential in fouling control, oil rejection and flux enhancement, but have their limitations.

scholarly journals Membrane Fouling Mechanisms in Combined Microfiltration-Coagulation of Algal Rich Water Applying Ceramic Membranes

Membranes ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 33 ◽  
Author(s):  
Kitae Park ◽  
Pooreum Kim ◽  
Hyoung Gun Kim ◽  
JiHoon Kim
Keyword(s):  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Ceramic Membranes ◽  
Constant Flow ◽  
Filtration Resistance ◽  
Fouling Mechanism ◽  
Coagulant Dosage ◽  
Cake Layer ◽  
Specific Cake Resistance ◽  
Resistance Value

In this paper, we investigated the membrane fouling mechanism according to the coagulant dosage in algal rich water using a ceramic membrane. The algae that were used in this experiment were Microcystis sp. of cyanobacteria, and the fouling mechanism was analyzed through irrigation and filtration resistance through a constant flow operation. The experimental results showed that the filtration resistance decreased as the coagulant dosage increased, but the irreversibility at above optimum coagulant dosage increased. Additionally, as the coagulant dosage increased, the resistance value due to cake and adsorption contamination decreased, and membrane fouling by adsorption was dominant in comparison with cake fouling and adsorption fouling. The specific cake resistance was decreased as the coagulant dosage increased. The characteristics of the cake layer according to the coagulant dosage were found to loosely form the cake layer by increasing micro-size algae as the coagulant dosage increased. The results of this experiment confirmed the membrane fouling mechanism according to coagulant dosage when the ceramic membrane filtered algal rich water.

Corrigendum to “Fenton cleaning strategy for ceramic membrane fouling in wastewater treatment” [J Environ Sci 85 (2019) 189-199]

2019 ◽  
Vol 86 ◽  
pp. 236
Author(s):  
Shengyin Tang ◽  
Lixun Zhang ◽  
Yi Peng ◽  
Jing Liu ◽  
Xihui Zhang ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Ceramic Membrane

scholarly journals Ozone Chemically Enhanced Backwash for Ceramic Membrane Fouling Control in Cyanobacteria-Laden Water

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 213
Author(s):  
Stéphane Venne ◽  
Onita D. Basu ◽  
Benoit Barbeau
Keyword(s):  
Surface Water ◽  
Surface Waters ◽  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Membrane Surface ◽  
Operating Costs ◽  
Fouling Control ◽  
Dead End ◽  
Cake Layer ◽  
Flow Experiments

Membrane fouling in surface waters impacted by cyanobacteria is currently poorly controlled and results in high operating costs. A chemically enhanced backwash (CEB) is one possible strategy to mitigate cyanobacteria fouling. This research investigates the potential of using an ozone CEB to control the fouling caused by Microcystis aeruginosa in filtered surface water on a ceramic ultrafiltration membrane. Batch ozonation tests and dead-end, continuous flow experiments were conducted with ozone doses between 0 and 19 mg O3/mg carbon. In all tests, the ozone was shown to react more rapidly with the filtered surface water foulants than with cyanobacteria. In addition, the ozone CEB demonstrated an improved mitigation of irreversible fouling over 2 cycles versus a single CEB cycle; indicating that the ozone CEB functioned better as the cake layer developed. Ozone likely weakens the compressible cake layer formed by cyanobacteria on the membrane surface during filtration, which then becomes more hydraulically reversible. In fact, the ozone CEB reduced the fouling resistance by 35% more than the hydraulic backwash when the cake was more compressed.

Integration of ceramic membrane and compressed air-assisted solvent extraction (CASX) for metal recovery

2010 ◽  
Vol 62 (6) ◽  
pp. 1274-1280 ◽  
Author(s):  
Chi-Wang Li ◽  
Chun-Hao Chiu ◽  
Yu-Cheng Lee ◽  
Chia-Hao Chang ◽  
Yu-Hsun Lee ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Removal Efficiency ◽  
Membrane Fouling ◽  
Water Solubility ◽  
Ceramic Membrane ◽  
Metal Removal ◽  
Membrane Surface ◽  
Extraction Process ◽  
Compressed Air ◽  
Dead End

In our previous publications, compressed air-assisted solvent extraction process (CASX) was developed and proved to be kinetically efficient process for metal removal. In the current study, CASX with a ceramic MF membrane integrated for separation of spent solvent was employed to remove and recover metal from wastewater. MF was operated either in crossflow mode or dead-end with intermittent flushing mode. Under crossflow mode, three distinct stages of flux vs. TMP (trans-membrane pressure) relationship were observed. In the first stage, flux increases with increasing TMP which is followed by the stage of stable flux with increasing TMP. After reaching a threshold TMP which is dependent of crossflow velocity, flux increases again with increasing TMP. At the last stage, solvent was pushed through membrane pores as indicated by increasing permeate COD. In dead-end with intermittent flushing mode, an intermittent flushing flow (2 min after a 10-min or a 30-min dead-end filtration) was incorporated to reduce membrane fouling by flush out MSAB accumulated on membrane surface. Effects of solvent concentration and composition were also investigated. Solvent concentrations ranging from 0.1 to 1% (w/w) have no adverse effect in terms of membrane fouling. However, solvent composition, i.e. D2EHPA/kerosene ratio, shows impact on membrane fouling. The type of metal extractants employed in CASX has significant impact on both membrane fouling and the quality of filtrate due to the differences in their viscosity and water solubility. Separation of MSAB was the limiting process controlling metal removal efficiency, and the removal efficiency of Cd(II) and Cr(VI) followed the same trend as that for COD.

Comparison of polymeric and ceramic membranes performance in the process of micellar enhanced ultrafiltration of cadmium(II) ions from aqueous solutions

2013 ◽  
Vol 67 (4) ◽  
Author(s):  
Katarzyna Staszak ◽  
Zofia Karaś ◽  
Karolina Jaworska
Keyword(s):  
Membrane Fouling ◽  
Permeability Coefficient ◽  
Ceramic Membrane ◽  
Polymer Membranes ◽  
Ceramic Membranes ◽  
Micellar Systems ◽  
Efficiency And Effectiveness ◽  
Micellar Enhanced Ultrafiltration ◽  
Hydrodynamic Permeability ◽  
Ultrafiltration Process

AbstractA comparison of polymeric and ceramic membranes in the ultrafiltration process was studied and presented. This study was conducted on the separation of cadmium(II) ions, with particular reference to parameters such as hydrodynamic permeability coefficient, membrane fouling, amount of surfactant in the permeate, efficiency, and effectiveness of the process. The effect of ionic (SDS) and non-ionic (Rofam 10) surfactants or their mixture was investigated. The hydrodynamic permeability coefficient of the ceramic membrane was found to be much lower in comparison to those of the polymeric ones (1.69 × 10−7 m3 h−1 m−2 Pa−1, 5.66 × 10−7 m3 h−1 m−2 Pa−1, and 9.26 × 10−7 m3 h−1 m−2 Pa−1 for ceramic, CA, and PVDF, respectively). However, filtration of the surfactants solutions did not cause permanent blocking of pores and the surface of the ceramic membrane in contrast to the polymeric ones. No significant differences in surfactants permeation through the membranes tested were observed. Concentration of the surfactant in the permeate was lower than 1 CMC for the Rofam 10 solution and exceeded the CMC by about 40 % for the SDS solution. Better separation properties of polymer membranes for the separation of cadmium(II) ions from micellar systems were identified.

Water Permeates in Ceramic Membrane Modified with Nano Inorganic Coating

2011 ◽  
Vol 239-242 ◽  
pp. 27-30
Author(s):  
Jian Er Zhou ◽  
Qi Bing Chang ◽  
Ying Chao Dong ◽  
Xue Bing Hu ◽  
Yong Qing Wang ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Membrane Surface ◽  
Molecular Layer ◽  
Pore Wall ◽  
Boundary Slip ◽  
Membrane Pore ◽  
Nano Coating ◽  
Inorganic Coating ◽  
Modified Membrane

Membrane surface modification is the important method to decrease membrane fouling. The hydrophilic modification of ceramic membrane with nano-sized inorganic coating is prepared by the wet chemical methods. The thin nano coating is not a separating top layer but distributes uniformly on the surface of the membrane pore wall. The coating does not change the structure of the membrane pores. Therefore, water flows on not the pore wall but the nano coating surface. The results show that the water flux of the modified membrane is higher than that of the unmodified membrane despite that the mean pore size of the modified membrane decreases. The “boundary slip” is used to explain this special phenomenon. What generates the slippage? The slippage is relative with the molecular layer adhered tightly on the hydrophilic pore wall, the roughness and the surface charge of the nano coating, the interaction between the ions in water and the nano coating, et al.

scholarly journals Design, construction and evaluation OFAN experimental ceramic membrane facility with investigation into fouling control

2021 ◽  
Author(s):  
Sarah Shim
Keyword(s):  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Ceramic Membranes ◽  
Membrane Unit ◽  
Membrane Cleaning ◽  
Fouling Control ◽  
Solids Concentration ◽  
Start Up ◽  
Water And Wastewater ◽  
Design Construction

During the past decade, the growth in membrane research and technology has advanced and multiplied in usage for many industries including water and wastewater. A major limitation of the application is due to membrane fouling. In this work, the construction, start-up calibration and testing of a membrane unit, as well as an examination into the fouling and cleaning aspect of the ceramic membranes are investigated. An aqueous solution containing precipitate is fed to the unit in order to observe fouling behaviour. Effluent wastewater from a bioreactor, CUBEN, is also tested with the unit and membrane cleaning is performed using various chemical agents. For both chemically enhanced backwash (CEB) and membrane soaking, hydrochloric acid cleaning agent «1 %w) produces best flux recoveries of 72.7% and 82%, respectively. All permeate effluent analysis, resulted in a suspended solids concentration <3 mgIL and turbidities. < 1 NTU, which both meet Ontario regulation limits.

scholarly journals Design, construction and evaluation OFAN experimental ceramic membrane facility with investigation into fouling control

2021 ◽  
Author(s):  
Sarah Shim
Keyword(s):  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Ceramic Membranes ◽  
Membrane Unit ◽  
Membrane Cleaning ◽  
Fouling Control ◽  
Solids Concentration ◽  
Start Up ◽  
Water And Wastewater ◽  
Design Construction

During the past decade, the growth in membrane research and technology has advanced and multiplied in usage for many industries including water and wastewater. A major limitation of the application is due to membrane fouling. In this work, the construction, start-up calibration and testing of a membrane unit, as well as an examination into the fouling and cleaning aspect of the ceramic membranes are investigated. An aqueous solution containing precipitate is fed to the unit in order to observe fouling behaviour. Effluent wastewater from a bioreactor, CUBEN, is also tested with the unit and membrane cleaning is performed using various chemical agents. For both chemically enhanced backwash (CEB) and membrane soaking, hydrochloric acid cleaning agent «1 %w) produces best flux recoveries of 72.7% and 82%, respectively. All permeate effluent analysis, resulted in a suspended solids concentration <3 mgIL and turbidities. < 1 NTU, which both meet Ontario regulation limits.

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