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.

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.

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.

Development of an Integrated Moving Bed Biofilm Reactor-Membrane Bioreactor for Wastewater Treatment

2013 ◽  
Vol 361-363 ◽  
pp. 611-614 ◽  
Author(s):  
Liang Duan ◽  
Yong Hui Song ◽  
Wei Jiang ◽  
Slawomir W. Hermanowicz
Keyword(s):  
Membrane Fouling ◽  
Membrane Surface ◽  
Biofilm Reactor ◽  
Moving Bed Biofilm Reactor ◽  
Filling Fraction ◽  
Moving Bed ◽  
Operating Modes ◽  
Dead End ◽  
The Media ◽  
Reactor Operating

Development of a MBBR-MBR has been investigated combining a moving bed biofilm reactor with a submerged membrane biomass separation reactor. Treatment efficiencies were found to be high with the production of a consistent high-quality effluent, irrespective of media fill ratio of MBBR or membrane reactor operating modes. There had some obvious fouling in MBR, MBBR and IFAS 3000, while no fouling were detected in IFAS 1500. The great difference indicated the media filling fraction have an important role and effect on membrane fouling. Traditional MBR and IFAS 3000 have more non-flocculating microorganisms in most time due to the mixed liquor suspended solids (MLSS) concentration. There had almost the same MLSS on media surface, independent of the volume of media and the MLSS concentration in each tank. The MBBR had more biomass enriched on membrane surface due to the dead end system.

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.

Application of Bdellovibrio bacteriovorus for reducing fouling of membranes used for wastewater treatment

2018 ◽  
Vol 43 (3) ◽  
pp. 296-305 ◽  
Author(s):  
Melek Özkan ◽  
Hilal Yılmaz ◽  
Merve Akay Çelik ◽  
Çişel Şengezer ◽  
Elif Erhan ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Hybridization Technique ◽  
Fish Analysis ◽  
Bdellovibrio Bacteriovorus ◽  
Steady State Condition ◽  
Dead End ◽  
Pure Cultures

Abstract Background: Membrane bioreactor (MBR) systems used for wastewater treatment (WWT) processes are regarded as clean technologies. Degradation capacity of the predator bacterium, Bdellovibrio bacteriovorus, was used as a cleaning strategy for reducing membrane fouling. Method: Wastewater with different sludge age and hydraulic retention time were filtered through Poly(ether)sulphone (PES) membranes using dead end reactor. Change in filtration performance after cleaning of membrane surface by B. bacteriovorus was measured by comparison of flux values. Bacterial community of the sludge was determined by 16SrRNA sequence analysis. Community profile of membrane surface was analyzed by fluorescent in situ hybridization technique. Results: After cleaning of MP005 and UP150 membranes with predator bacteria, 4.8 L/m2·h and 2.04 L/m2·h increase in stable flux at steady state condition was obtained as compared to the control, respectively. Aeromonas, Proteus, and Alcaligenes species were found to be dominant members of the sludge. Bdellovibrio bacteriovorus lysed pure cultures of the isolated sludge bacteria successfully. FISH analysis of the membrane surface showed that Alfa-proteobacteria are the most numerous bacteria among the biofilm community on the membrane surface. Conclusion: Results suggested that cleaning of MBR membranes with B. bacteriovorus has a potential to be used as a biological cleaning method.

Virus removal by ceramic membrane microfiltration with coagulation pretreatment

2003 ◽  
Vol 3 (5-6) ◽  
pp. 93-99 ◽  
Author(s):  
Y. Matsui ◽  
T. Matsushita ◽  
T. Inoue ◽  
M. Yamamoto ◽  
Y. Hayashi ◽  
...  
Keyword(s):  
High Performance ◽  
Ceramic Membrane ◽  
Membrane Surface ◽  
Membrane System ◽  
Positive Pressure ◽  
Virus Inactivation ◽  
Virus Removal ◽  
Virus Adsorption ◽  
Dead End ◽  
Pressure Driven

The performance and mechanism of virus removal by microfiltration with coagulation pretreatment were investigated. We confirmed the unexpectedly high performance of virus removal for two types of ceramic membrane system: a positive pressure-driven dead-end filtration with inside-out configuration and a vacuum pressure-driven dead-end immersed filtration with outside-in configuration. Virus removals by both systems were more than 7 logs, although the size of the tested Qβ virus (23 nm) was much smaller than the membrane nominal pore size of 100 nm. The virus inactivation by the addition of the coagulant (PACl) and the virus adsorption onto the floc retained on the membrane surface mainly contributed the virus removal. No virus accumulation in the retentate was observed, possibly due to the virus inactivation by the coagulant.

scholarly journals Intermittent Ultrasound-Assisted Ceramic Membrane Fouling Control in Ultrafiltration

2021 ◽  
Author(s):  
Kyu Min Lee ◽  
Farhad Ein-Mozaffari
Keyword(s):  
Flow Rate ◽  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Membrane Surface ◽  
Operating Cost ◽  
Feed Solution ◽  
Time Interval ◽  
Short Time Interval ◽  
Feed Concentration ◽  
Power Intensity

Ultrafiltration is one of the most promising membrane technologies for liquid purification due to its high economic efficiency in the industries. However, it has been faced with a critical problem, called fouling. The contaminants in feed solution tend to accumulate on the membrane surface, hindering permeate solution to pass through the porous spaces. Among the various solutions, application of ultrasound has been considered as the most popular method since it does not suffer a disadvantage of downtime and the filtration process does not need to be stopped for the removal of foulants. In this study, control of ceramic membrane fouling by an on-line intermittent ultrasound system was being investigated. The experiment focused on obtaining optimal operating ultrasonic condition. Frequency (20, 28, and 40 kHz), power intensity (1.44, 2.88, and 5.76W/cm2 ), and time interval of intermittent ultrasound (1, 1.5, and 2 minutes) were the parameters of interest. The effect of feed concentration was also analyzed at optimal ultrasonic condition. The quality and flow rate of the permeate streams were monitored for the evaluation of the process performance. The optimal condition of intermittent ultrasound was found at the frequency of 28 kHz and the power intensity of 2.88 W/cm2 ; and then, the application of intermittent ultrasound with short time interval successfully reduced the operating cost of ultrafiltration process while maintaining acceptable quality and flow rate of permeate solution. There was increase in efficiency of intermittent ultrasound at lower feed concentration.

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