scholarly journals UV and bacteriophages as a chemical-free approach for cleaning membranes from anaerobic bioreactors

2021 ◽  
Vol 118 (37) ◽  
pp. e2016529118
Author(s):  
Giantommaso Scarascia ◽  
Luca Fortunato ◽  
Yevhen Myshkevych ◽  
Hong Cheng ◽  
TorOve Leiknes ◽  
...  
Keyword(s):  
Membrane Bioreactor ◽  
Combined Treatment ◽  
Water Flux ◽  
Energy Costs ◽  
Chemical Cleaning ◽  
Similar Reduction ◽  
Anaerobic Bioreactors ◽  
Membrane Biofouling ◽  
The Common ◽  
Uv C

Anaerobic membrane bioreactor (AnMBR) for wastewater treatment has attracted much interest due to its efficacy in providing high-quality effluent with minimal energy costs. However, membrane biofouling represents the main bottleneck for AnMBR because it diminishes flux and necessitates frequent replacement of membranes. In this study, we assessed the feasibility of combining bacteriophages and UV-C irradiation to provide a chemical-free approach to remove biofoulants on the membrane. The combination of bacteriophage and UV-C resulted in better log cells removal and ca. 2× higher extracellular polymeric substance (EPS) concentration reduction in mature biofoulants compared to either UV-C or bacteriophage alone. The cleaning mechanism behind this combined approach is by 1) reducing the relative abundance of Acinetobacter spp. and selected bacteria (e.g., Paludibacter, Pseudomonas, Cloacibacterium, and gram-positive Firmicutes) associated with the membrane biofilm and 2) forming cavities in the biofilm to maintain water flux through the membrane. When the combined treatment was further compared with the common chemical cleaning procedure, a similar reduction on the cell numbers was observed (1.4 log). However, the combined treatment was less effective in removing EPS compared with chemical cleaning. These results suggest that the combination of UV-C and bacteriophage have an additive effect in biofouling reduction, representing a potential chemical-free method to remove reversible biofoulants on membrane fitted to an AnMBR.

scholarly journals UV and bacteriophages as a chemical-free approach for cleaning membranes from anaerobic bioreactors

2020 ◽  
Author(s):  
Giantommaso Scarascia ◽  
Luca Fortunato ◽  
Yevhen Myshkevych ◽  
Hong Cheng ◽  
TorOve Leiknes ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Combined Treatment ◽  
Chemical Cleaning ◽  
High Quality ◽  
Anaerobic Membrane Bioreactor ◽  
Membrane Biofouling ◽  
Uv C

ABSTRACTAnaerobic membrane bioreactor (AnMBR) for wastewater treatment has attracted much interest due to its efficacy in providing high quality effluent with minimal energy costs. However, membrane biofouling represents the main bottleneck for AnMBR because it diminishes flux and necessitates frequent replacement of membranes. In this study, we assessed the feasibility of combining bacteriophages and UV-C irradiation to provide a chemical-free approach to remove biofoulants on the membrane. The combination of bacteriophage and UV-C resulted in better log cells removal and twice higher extracellular polymeric substance (EPS) concentration reduction in mature biofoulants compared to UV-C. A reduction in the relative abundance of Acinetobacter spp. and selected gram-positive bacteria associated with the membrane biofilm was also achieved by the new cleaning approach. Microscopic analysis further revealed the formation of cavities in the biofilm due to bacteriophages and UV-C irradiation, which would be beneficial to maintain water flux through the membrane. When the combined treatment was further compared with the common chemical cleaning procedure, a similar reduction on the cell numbers was observed (1.4 log). However, combined treatment was less effective in removing EPS compared with chemical cleaning. These results suggest that the combination of UV-C and bacteriophage have an additive effect in biofouling reduction, representing a potential chemical-free method to remove reversible biofoulants on membrane fitted in an anaerobic membrane bioreactor.SIGNIFICANCEAnaerobic membrane bioreactors can achieve high quality effluent with a reduced energy consumption. However, biofouling represents the main bottleneck for membrane filtration efficiency. Biofouling is commonly reduced through chemical treatment. These agents are often detrimental for the environment and health safety due to the formation of toxic byproducts. Therefore, we present a new approach, based on the additive antifouling action of bacteriophages infection and UV-C irradiation, to reduce anaerobic membrane biofouling. This new strategy could potentially delay the occurrence of membrane fouling by removing the reversible fouling layers on membranes, in turn reducing the frequencies and amount of chemicals needed throughout the course of wastewater treatment.

scholarly journals Application of cell entrapping beads for Quorum Quenching technique in submerged membrane bioreactor

2020 ◽  
Vol 81 (4) ◽  
pp. 744-752
Author(s):  
S. Ahmed ◽  
S. Chung ◽  
N. Sohail ◽  
I. A. Qazi ◽  
A. Justin
Keyword(s):  
Sodium Alginate ◽  
Biofilm Formation ◽  
Membrane Bioreactor ◽  
Membrane Surface ◽  
Quorum Quenching ◽  
Chemical Cleaning ◽  
Submerged Membrane Bioreactor ◽  
Membrane Biofouling ◽  
Market Disruption ◽  
Physical And Chemical

Abstract Biofouling is unwanted accumulation of microbial population on the membrane surface which limits the use of membrane bioreactor (MBR) in the market. Disruption of the biofilm formation by Quorum Quenching (QQ) by using cell entrapping beads (CEBs) is an approach with great potential to control membrane biofouling as the beads used provide not only mitigating effect on biofilm formation, by interfering Quorum Sensing, but also physical forces to detach the biofilm from the membrane surface. This research aimed to develop QQ-CEB with locally available chemicals in Pakistan and its application to evaluate the QQ effect together with physical and chemical cleaning. Various CEBs were made of different mixtures of sodium alginate and polyvinyl alcohol (PVA) and their quality was tested considering physical and biological aspects. Rhodococcus sp. BH4 and Pseudomonas putida were entrapped in the CEBs and then introduced in MBR as one of biofouling control methods along with standard backwash and chemical backwash. The CEBs made of specific concentration of PVA were proven to be more durable and helpful in mitigating biofouling as compared to that of sodium alginate. An MBR operated with PVA-alginate QQ CEBs together with chemical backwash showed the best performance without deterioration of effluent quality.

Reduction of Listeria monocytogenes on chicken breasts by combined treatment with UV-C light and bacteriophage ListShield

LWT ◽  
2017 ◽  
Vol 86 ◽  
pp. 193-200 ◽  
Author(s):  
Sungdae Yang ◽  
Mohammad Sadekuzzaman ◽  
Sang-Do Ha
Keyword(s):  
Listeria Monocytogenes ◽  
Combined Treatment ◽  
Uv C

Kinetic evaluation of nitrification performance in an immobilized cell membrane bioreactor

2016 ◽  
Vol 73 (12) ◽  
pp. 2904-2912 ◽  
Author(s):  
D. Güven ◽  
E. Ubay Çokgör ◽  
S. Sözen ◽  
D. Orhon
Keyword(s):  
Residence Time ◽  
Retention Time ◽  
Model Calibration ◽  
Membrane Bioreactor ◽  
Hydraulic Retention Time ◽  
Membrane Bioreactors ◽  
High Rate ◽  
Immobilized Cell ◽  
Chemical Cleaning ◽  
Kinetic Evaluation

Abstract High rate membrane bioreactor (MBR) systems operated at extremely low sludge ages (superfast membrane bioreactors (SFMBRs)) are inefficient to achieve nitrogen removal, due to insufficient retention time for nitrifiers. Moreover, frequent chemical cleaning is required due to high biomass flux. This study aims to satisfy the nitrification in SFMBRs by using sponge as carriers, leading to the extension of the residence time of microorganisms. In order to test the limits of nitrification, bioreactor was run under 52, 5 and 2 days of carrier residence time (CRT), with a hydraulic retention time of 6 h. Different degrees of nitrification were obtained for different CRTs. Sponge immobilized SFMBR operation with short CRT resulted in partial nitrification indicating selective dominancy of ammonia oxidizers. At higher CRT, simultaneous nitrification–denitrification was achieved when accompanying with oxygen limitation. Process kinetics was determined through evaluation of the results by a modeling study. Nitrifier partition in the reactor was also identified by model calibration.

scholarly journals Optimization of In Situ Backwashing Frequency for Stable Operation of Anaerobic Ceramic Membrane Bioreactor

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 545 ◽  
Author(s):  
Rathmalgodage Thejani Nilusha ◽  
Tuo Wang ◽  
Hongyan Wang ◽  
Dawei Yu ◽  
Junya Zhang ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Ceramic Membrane ◽  
Pure Water ◽  
Ex Situ ◽  
Stable Operation ◽  
Chemical Cleaning ◽  
Cake Layer

The cost-effective and stable operation of an anaerobic ceramic membrane bioreactor (AnCMBR) depends on operational strategies to minimize membrane fouling. A novel strategy for backwashing, filtration and relaxation was optimized for stable operation of a side stream tubular AnCMBR treating domestic wastewater at the ambient temperature. Two in situ backwashing schemes (once a day at 60 s/day, and twice a day at 60 s × 2/day) maintaining 55 min filtration and 5 min relaxation as a constant were compared. A flux level over 70% of the initial membrane flux was stabilized by in situ permeate backwashing irrespective of its frequency. The in situ backwashing by permeate once a day was better for energy saving, stable membrane filtration and less permeate consumption. Ex situ chemical cleaning after 60 days’ operation was carried out using pure water, sodium hypochlorite (NaOCl), and citric acid as the order. The dominant cake layer was effectively reduced by in situ backwashing, and the major organic foulants were fulvic acid-like substances and humic acid-like substances. Proteobacteria, Firmucutes, Epsilonbacteria and Bacteroides were the major microbes attached to the ceramic membrane fouling layer which were effectively removed by NaOCl.

Antibiofilm activity of biomolecules: gene expression study of bacterial isolates from brackish and fresh water biofouled membranes

Biologia ◽  
2016 ◽  
Vol 71 (3) ◽  
Author(s):  
Smita Pal ◽  
Asifa Qureshi ◽  
Hemant J. Purohit
Keyword(s):  
Salicylic Acid ◽  
Fresh Water ◽  
Industrial Process ◽  
Life Time ◽  
Antibiofilm Activity ◽  
Expression Study ◽  
Chemical Cleaning ◽  
Natural Agents ◽  
Membrane Biofouling ◽  
Exopolysaccharides Production

AbstractMembrane biofouling is a common and emerging problem, where cells get cemented and create problems in industrial process. Frequent chemical cleaning used for the treatment of biofouled membrane shortens the membrane life time and creates ‘stress’ to existing microflora to trigger more exopolysaccharides production, which becomes the principle cause of biofouling. To understand safe and environmentally feasible antifouling strategies, key biofilm forming representative bacteria isolated from brackish and fresh water biofouled membranes were subjected to natural agents, such as vanillin (0.05–0.4 mg/mL) and salicylic acid (0.1–0.7 mg/mL). Salicylic acid (0.7 mg/mL) was found to be effective against only

scholarly journals Stimulatory effects on bacteria induced by chemical cleaning cause severe biofouling of membranes

2020 ◽  
Vol 10 (1) ◽  
pp. 82-94
Author(s):  
Xueye Wang ◽  
Jinxing Ma ◽  
Zhichao Wu ◽  
Zhiwei Wang
Keyword(s):  
Membrane Surface ◽  
Oxygen Species ◽  
Cleaning Efficiency ◽  
Chemical Cleaning ◽  
Physiological Mechanisms ◽  
Homoserine Lactones ◽  
Membrane Surfaces ◽  
Enhanced Production ◽  
Membrane Biofouling ◽  
Microbial Regrowth

Abstract Chemical cleaning with hypochlorite is routinely used in membrane-based processes. However, a high-transient cleaning efficiency does not guarantee a low biofouling rate when filtration is restarted, with the physiological mechanisms largely remaining unknown. Herein, we investigated the microbial regrowth and surface colonization on membrane surfaces after NaOCl cleaning had been completed. Results of this study showed that the regrowth of model bacteria, Pseudomonas aeruginosa, was initially subject to inhibition due to the damage of key enzymes' activity and the accumulation of intracellular reactive oxygen species although the oxidative stress induced by NaOCl had been removed. However, with the resuscitation ongoing, the stimulatory effects became obvious, which was associated with the enhanced production of N-acyl homoserine lactones and the secretion of eDNA that ultimately led to more severe biofouling on the membrane surface. This study elucidates the inhibition–stimulation mechanisms involved in biofilm reformation (membrane biofouling) after membrane chemical cleaning, which is of particular significance to the improvement of cleaning efficiency and application of membrane technologies.

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