scholarly journals Ozone Chemically-Enhanced Backwashes For Ceramic Membrane Fouling Control in Cyanobacteria-Laden Surface Water Applications

2020 ◽  
Author(s):  
Stephane Venne
Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 213
Author(s):  
Stéphane Venne ◽  
Onita D. Basu ◽  
Benoit Barbeau

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.


Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 369
Author(s):  
Shengji Xia ◽  
Xinran Zhang ◽  
Yuanchen Zhao ◽  
Fibor J. Tan ◽  
Pan Li ◽  
...  

The membrane separation process is being widely used in water treatment. It is very important to control membrane fouling in the process of water treatment. This study was conducted to evaluate the efficiency of a pre-oxidation-coagulation flat ceramic membrane filtration process using different oxidant types and dosages in water treatment and membrane fouling control. The results showed that under suitable concentration conditions, the effect on membrane fouling control of a NaClO pre-oxidation combined with a coagulation/ceramic membrane system was better than that of an O3 system. The oxidation process changed the structure of pollutants, reduced the pollution load and enhanced the coagulation process in a pre-oxidation-coagulation system as well. The influence of the oxidant on the filtration system was related to its oxidizability and other characteristics. NaClO and O3 performed more efficiently than KMnO4. NaClO was more conducive to the removal of DOC, and O3 was more conducive to the removal of UV254.


2021 ◽  
Author(s):  
Sarah Shim

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.


2021 ◽  
Author(s):  
Sarah Shim

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.


2000 ◽  
Vol 41 (10-11) ◽  
pp. 363-371 ◽  
Author(s):  
K-H. Choo ◽  
I-J. Kang ◽  
S-H. Yoon ◽  
H. Park ◽  
J-H. Kim ◽  
...  

Various fouling control methods were investigated for polymeric and ceramic microfiltration membranes in the anaerobic membrane bioreactors where inorganic precipitates and/or fine colloids have been recently known as the most significant foulants: (i) Substantial improvement of flux was achieved by backfeeding of acidic wastewater through the membrane module. The backfeeding mode formed an acidic environment around the membrane pores and thus suppressed struvite formation. (ii) Struvite precipitation was also mitigated when an additional combined dialysis/zeolite unit was attached to the bioreactor. With this combined unit the flux improvement for the ceramic membrane, where struvite had a severer fouling effect, was achieved more significantly than that for the polymeric membrane. (iii) To control the deposition of organics and fine colloids onto the polymeric membrane, powdered activated carbon (PAC) was added into the bioreactor, which gave rise to the reduction of specific cake resistances of biosolids through the sorption and/or coagulation of dissolved and colloidal matter. (iv) The hydrophilic modification of polypropylene (PP) membranes by graft polymerization reduced membrane fouling. Its effectiveness was most substantial at 70% of the degree of grafting, indicating that there was an optimal degree of grafting. This is possibly due to the steric hindrance of grafted polymer chains and the increase in the hydrophilicity of the grafted PP membrane.


2021 ◽  
Author(s):  
Sarah Shim

During the past decade, the growth in membrane research and technology 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 <3mg/L and turbidities <1NTU, which both meet Ontario regulation limits.


Author(s):  
Prattakorn Sittisom ◽  
Obey Gotore ◽  
Rameshprabu Ramaraj ◽  
Giang Tran Van ◽  
Yuwalee Unpaprom ◽  
...  

Anaerobic Membrane Bioreactor (AnMBR) technology in recent years has been actively used for municipal and industrial wastewater treatment. Also, AnMBR technology has been considered as an alternative wastewater treatment application over conventional activated sludge system. AnMBRs are best possible operated with flat sheet, hollow fiber, or tubular membranes both in the microfiltration or in the ultrafiltration, but on ceramic membrane use has not been reported widely. AnMBRs are a desirable technology that needs additional research efforts and development. However, membrane fouling, which continues a major problem for all membrane bioreactors, seems much more serious under anaerobic than aerobic conditions. In this review, membrane fouling issues (including membrane fouling mechanism, classification, influent parameters, and mitigation) were discussed and summarized. Moreover, in fouling control, biogas sparging and recirculation (i.e. methane production) were addressed. Lastly, future research perspectives relating to its application and membrane fouling research are planned.


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