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.

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.

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.

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.

Substrate uptake by Gordonia amarae in activated sludge foams by FISH-MAR

2006 ◽  
Vol 54 (1) ◽  
pp. 39-45 ◽  
Author(s):  
E.L. Carr ◽  
K.L. Eales ◽  
R.J. Seviour
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Carbon Sources ◽  
Mycolic Acid ◽  
Substrate Uptake ◽  
Wastewater Treatment Process ◽  
Pure Cultures ◽  
Gordonia Amarae

Gordonia amarae is a right-angled branching filament belonging to the mycolic acid-containing Actinobacteria which is commonly found in many foaming activated sludge wastewater treatment plants. Although studies on different substrates as sole carbon sources by pure cultures of G. amarae have been carried out, none have examined substrate uptake by this organism in situ. Uptake of several hydrophilic and hydrophobic substrates by G. amarae was evaluated in situ using a combination of fluorescence in situ hybridization and microautoradiography. G. amarae could assimilate a range of both hydrophilic and hydrophobic substrates. From the data, G. amarae appears to be physiologically active under aerobic, anaerobic and anoxic condition (NO2 and NO3) for some substrates. This might explain why attempts to control foaming caused by G. amarae using anoxic and anaerobic selectors have been unsuccessful. This study emphasizes that bacteria can behave differently in situ to pure cultures and that it is important to evaluate the in situ physiology of these bacteria if we are to better understand their role in the wastewater treatment process.

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 A novel In-situ Enzymatic Cleaning Method for Reducing Membrane Fouling in Membrane Bioreactors (MBRs)

2016 ◽  
Vol 1 (1) ◽  
pp. 1 ◽  
Author(s):  
M. R. Bilad ◽  
M. Baten ◽  
A. Pollet ◽  
C. Courtin ◽  
J. Wouters ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
High Performance ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Anion Exchange Chromatography ◽  
Magnetic Activity ◽  
Exchange Chromatography ◽  
Membrane Bioreactors ◽  
Cleaning Method

A novel in-situ enzymatic cleaning method was developed for fouling control in membrane bioreactors (MBRs). It is achieved by bringing the required enzymes near the membrane surface by pulling the enzymes to a magnetic membrane (MM) surface by means of magnetic forces, exactly where the cleaning is required. To achieve this, the enzyme was coupled to a magnetic nanoparticle (MNP) and the membrane it self was loaded with MNP. The magnetic activity was turned by means of an external permanent magnet. The effectiveness of concept was tested in a submerged membrane filtration using the model enzyme-substrate of Bacillus subitilis xylanase-arabinoxylan. The MM had almost similar properties compared to the unloaded ones, except for its well distributed MNPs. The enzyme was stable during coupling conditions and the presence of coupling could be detected using a high-performance anion-exchange chromatography (HPAEC) analysis and Fourier transform infrared spectroscopy (FTIR). The system facilitated an in-situ enzymatic cleaning and could be effectively applied for control fouling in membrane bioreactors (MBRs).

Domestic wastewater treatment by a submerged MBR (membrane bio-reactor) with enhanced air sparging

2003 ◽  
Vol 47 (12) ◽  
pp. 149-154 ◽  
Author(s):  
I.-S. Chang ◽  
S.J. Judd
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Gas Flow ◽  
Domestic Wastewater ◽  
Air Sparging ◽  
Air Jet ◽  
Dead End ◽  
Membrane Tube ◽  
Cake Layer ◽  
Air Lift

The air sparging technique has been recognised as an effective way to control membrane fouling. However, its application to a submerged MBR (Membrane Bio-Reactor) has not yet been reported. This paper deals with the performances of air sparging on a submerged MBR for wastewater treatment. Two kinds of air sparging techniques were used respectively. First, air is injected into the membrane tube channels so that mixed liquor can circulate in the bioreactor (air-lift mode). Second, a periodic air-jet into the membrane tube is introduced (air-jet mode). Their applicability was evaluated with a series of lab-scale experiments using domestic wastewater. The flux increased from 23 to 33 lm−2h−1 (43% enhancement) when air was injected for the air-lift module. But further increase of flux was not observed as the gas flow increased. The Rc/(Rc+Rf), ratio of cake resistance (Rc) to sum of Rc and Rf (internal fouling resistance), was 23%, indicating that the Rc is not the predominant resistance unlike other MBR studies. It showed that the cake layer was removed sufficiently due to the air injection. Thus, an increase of air flow could not affect the flux performance. The air-jet module suffered from a clogging problem with accumulated sludge inside the lumen. Because the air-jet module has characteristics of dead end filtration, a periodic air-jet was not enough to blast all the accumulated sludge out. But flux was greater than in the air-lift module if the clogging was prevented by an appropriate cleaning regime such as periodical backwashing.

Design considerations for wastewater treatment by reverse osmosis

2005 ◽  
Vol 51 (6-7) ◽  
pp. 473-482 ◽  
Author(s):  
C.R. Bartels ◽  
M. Wilf ◽  
K. Andes ◽  
J. Iong
Keyword(s):  
Wastewater Treatment ◽  
Calcium Phosphate ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Urban Areas ◽  
Large Scale ◽  
Membrane Surface ◽  
Feed Water ◽  
High Quality ◽  
Quality Water

Reverse Osmosis is finding increasing use for the treatment of municipal and industrial wastewaters due to the growing demand for high quality water in large urban areas. The growing success of membranes in this application is related to improved process designs and improved membrane products. Key factors which have been determined to result in successful operation of large-scale plants will be discussed. Factors which play a key role in the use of RO membranes include ultra or microfiltration pretreatment, low fouling membranes, flux rate, recovery and control of fouling and scaling. In particular, high flux rates can be used when UF or MF pretreatment is used. These technologies remove most of the suspended particles that would normally cause heavy fouling of lead elements. Typically, fluxes in the range of 17–21 lmh lead to cleaning frequencies in the range of 3–4 months. By combining the use of membrane pretreatment and chloramination of the feed water through chlorine addition, two of the primary sources of RO membrane fouling can be controlled. The use of chloramine has become a proven means to control biofouling in a membrane for wastewater applications. The other significant problems for RO membranes result from organics fouling by dissolved organics and scaling due to saturation of marginally soluble salts. The former can be a significant problem for membranes, due to the strong attraction forces. To some extent, these can be mitigated by making the membrane surface more hydrophilic or changing the charge of the membrane surface. To minimize fouling, many plants are turning to low fouling membranes. Extensive studies have demonstrated that the membrane surface is hydrophilic, neutrally charged over a broad pH range, and more resistant to organic adsorption. Also, an analysis of the potential scaling issues will be reviewed. In particular, calcium phosphate has been found to be one of the key scalants that will limit RO system recovery rate. Calcium phosphate concentrations can reach high values in many wastewaters, and scaling of this compound is not often modeled in most RO projection software. Various process options will be presented to evaluate the most economic means of avoiding phosphate scaling. Finally, data from major RO wastewater treatment plants will be presented to show how the RO membranes operate under actual conditions, utilizing many of these design features. Long term data from the 2.6 mgd Bedok demonstration Plant demonstrate that the RO membranes operate consistently on wastewater. Experiences from the 8.5 mgd (32,000 m3/day) Bedok and 10.5 mgd (40,000 m3/day) Kranji plants will also be presented. These large plants started operation in the fall of 2002 and have demonstrated an effective means to reclaim high quality water from difficult source waters, such as municipal wastewaters.

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