scholarly journals Comparison of ferric chloride and aluminum sulfate on phosphorus removal and membrane fouling in MBR treating BAF effluent of municipal wastewater

2016 ◽  
Vol 7 (4) ◽  
pp. 442-448 ◽  
Author(s):  
Xin Li ◽  
Yali Liu ◽  
Fangfang Liu ◽  
Aimin Liu ◽  
Qilan Feng
Keyword(s):  
Ferric Chloride ◽  
Membrane Fouling ◽  
Phosphorus Removal ◽  
Aluminum Sulfate ◽  
Municipal Wastewater ◽  
Transmembrane Pressure ◽  
Particle Sizes ◽  
Fouling Control ◽  
Aerated Filter ◽  
Sludge Particle

A membrane bioreactor (MBR) was used for treating biological aerated filter effluent in a municipal wastewater plant, and chemical phosphorus removal was accomplished in the MBR. The results showed that ferric chloride of 20 mg/L and aluminum sulfate of 30 mg/L were the optimal dosages for total phosphorus (TP) removal, and the TP removal efficiency was over 80%. In long-term continuous operations, both ferric chloride and aluminum sulfate effectively mitigated membrane fouling, with the corresponding growth rate of transmembrane pressure decreased to 0.08 and 0.067 kPa/d, respectively. Sludge particle sizes analysis demonstrated that the decrease of particle sizes lower than 50 μm was the main reason for membrane fouling control. Simultaneously, the proteins and polysaccharide (PS) concentrations in the MBR supernatant were analyzed, and the PS concentration significantly decreased to 2.02 mg/L at aluminum sulfate of 30 mg/L, indicating the flocculation of aluminum sulfate on PS was the main reason for mitigation of membrane fouling.

Effect of a suspended carrier on membrane fouling in a submerged membrane bioreactor

2006 ◽  
Vol 53 (6) ◽  
pp. 211-220 ◽  
Author(s):  
Chun-Hai Wei ◽  
Xia Huang ◽  
Cheng-Wen Wang ◽  
Xiang-Hua Wen
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Membrane Surface ◽  
Transmembrane Pressure ◽  
Fouling Control ◽  
Submerged Membrane Bioreactor ◽  
Negative Effect ◽  
Sludge Particle ◽  
Carrier Volume ◽  
Suspended Carrier

In an attempt at membrane fouling control, a kind of cylindrical plastic suspended carrier was added in a submerged membrane bioreactor (SMBR) and its effect was investigated in this study. According to the transmembrane pressure (TMP) profiles and the sludge characteristics in comparative runs with and without suspended carriers, it was found that the suspended carriers added in SMBR had two effects on membrane fouling: one was the positive effect of mechanically scouring the membrane surface and the other was the negative effect of breaking up sludge flocs. Sludge particle size distribution change was mainly responsible. It was suggested to apply the suspended carrier at higher MLSS concentration and lower carrier dose based on the consideration for retarding sludge breakage caused by the carrier. The experiment was conducted under higher MLSS (8 g L−1) and lower carrier dose (carrier volume/total volume = 1%). The TMP increase was effectively retarded by added suspended carriers compared to the system without addition of the carriers. The effect of suspended carriers on membrane fouling at high MLSS concentration was verified.

scholarly journals Membrane Fouling Controlled by Adjustment of Biological Treatment Parameters in Step-Aerating MBR

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 553
Author(s):  
Dimitra C. Banti ◽  
Manassis Mitrakas ◽  
Petros Samaras
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Municipal Wastewater ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Aeration Tank ◽  
Filamentous Bacteria ◽  
Membrane Performance ◽  
Low Concentrations ◽  
Fouling Reduction

A promising solution for membrane fouling reduction in membrane bioreactors (MBRs) could be the adjustment of operating parameters of the MBR, such as hydraulic retention time (HRT), food/microorganisms (F/M) loading and dissolved oxygen (DO) concentration, aiming to modify the sludge morphology to the direction of improvement of the membrane filtration. In this work, these parameters were investigated in a step-aerating pilot MBR that treated municipal wastewater, in order to control the filamentous population. When F/M loading in the first aeration tank (AT1) was ≤0.65 ± 0.2 g COD/g MLSS/d at 20 ± 3 °C, DO = 2.5 ± 0.1 mg/L and HRT = 1.6 h, the filamentous bacteria were controlled effectively at a moderate filament index of 1.5–3. The moderate population of filamentous bacteria improved the membrane performance, leading to low transmembrane pressure (TMP) at values ≤2 kPa for a great period, while at the control MBR the TMP gradually increased reaching 14 kPa. Soluble microbial products (SMP), were also maintained at low concentrations, contributing additionally to the reduction of ΤΜP. Finally, the step-aerating MBR process and the selected imposed operating conditions of HRT, F/M and DO improved the MBR performance in terms of fouling control, facilitating its future wider application.

Effect of chemical dose on phosphorus removal and membrane fouling control in a UCT-MBR

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Guangrong Sun ◽  
Chuanyi Zhang ◽  
Wei Li ◽  
Limei Yuan ◽  
Shilong He ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Phosphorus Removal ◽  
Fouling Control

scholarly journals Long-Term Investigation into the Membrane Fouling Behavior in Anaerobic Membrane Bioreactors for Municipal Wastewater Treatment Operated at Two Different Temperatures

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 231
Author(s):  
Yi Ding ◽  
Zhansheng Guo ◽  
Zhenlin Liang ◽  
Xuguang Hou ◽  
Zhipeng Li ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Membrane Bioreactors ◽  
Municipal Wastewater Treatment ◽  
Sludge Flocs ◽  
Microbial Product ◽  
Anaerobic Membrane Bioreactors ◽  
Sludge Particle

In this study, the characteristics of activated sludge flocs were investigated and their effects on the evolution of membrane fouling were considered in the anaerobic membrane bioreactors (AnMBR), which were operated at 25 and 35 °C for municipal wastewater treatment. It was found that the membrane fouling rate of the AnMBR at 25 °C was more severe than that at 35 °C. The membrane fouling trends were not consistent with the change in the concentration of soluble microbial product (SMP). The larger amount of SMP in the AnMBR at 35 °C did not induce more severe membrane fouling than that in the AnMBR at 25 °C. However, the polysaccharide and protein concentration of extracellular polymeric substance (EPS) was higher in the AnMBR at 25 °C in comparison with that in the AnMBR at 35 °C, and the protein/polysaccharide ratio of the EPS in the AnMBR at 25 °C was higher in contrast to that in the AnMBR at 35 °C. Meanwhile, the fouling tendencies measured for the AnMBRs could be related to the characteristics of loosely bound EPS and tightly bound EPS. The analysis of the activated sludge flocs characteristics indicated that a smaller sludge particle size and more fine flocs were observed at the AnMBR with 25 °C. Therefore, the membrane fouling potential in the AnMBR could be explained by the characteristics of activated sludge flocs.

scholarly journals Impacts of the specific cake resistance on mbr fouling for wastewater treatment

2021 ◽  
Vol 72 (7) ◽  
pp. 841-849
Author(s):  
Guigui Christelle ◽  
Nga Vu Thi Thu
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Peak Height ◽  
Transmembrane Pressure ◽  
Strongly Correlated ◽  
Municipal Wastewater Treatment ◽  
Fouling Resistance ◽  
Sustainable Operation ◽  
Specific Cake Resistance

Membrane bioreactor (MBR) has been increasingly used for municipal wastewater treatment and reuse due to its good effluent quality. However, membrane fouling remains the major limitation of MBR. Understanding fouling is still a key issue for a more sustainable operation of MBRs. Thus, this research presents the influence of specific cake resistance (α) on the fouling propensity in the MBR. Correlation between α value with fouling resistance (Rf), fouling rate (dTMP/dt), especially of peak height 100-1000 kDa protein-like SMPs was investigated. The result reported that the α value was strongly correlated with the dTMP/dt in the MBR (R2 value of close to 1). In this study, however, there is an obvious discrepancy between the fouling resistance calculated from the resistance in the series model and the α value in the supernatant filtration. These observations demonstrated that the fouling propensities of the membrane could be monitored by the transmembrane pressure and the fouling characteristics, include fouling resistance and specific cake resistance in the filtration cell.

Air bubbling for membrane fouling control in a submerged direct forward osmosis system for municipal wastewater treatment

2019 ◽  
Vol 5 (4) ◽  
pp. 684-692 ◽  
Author(s):  
Yan Sun ◽  
Shanshan Gao ◽  
Jiayu Tian ◽  
Xiujuan Hao ◽  
Zhiquan Liu ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Water Flux ◽  
Forward Osmosis ◽  
Municipal Wastewater Treatment ◽  
Fouling Control

Air bubbling along the membrane improves water flux, alleviates the deposition of foulants and inhibits the formation of a fouling layer.

Phosphorus Removal in Biological Aerated Filters by Chemically Enhanced

2011 ◽  
Vol 243-249 ◽  
pp. 4821-4826 ◽  
Author(s):  
Ying Ying Ma ◽  
Xin Li ◽  
Wen Yi Dong
Keyword(s):  
Ferric Chloride ◽  
Aluminum Chloride ◽  
Phosphorus Removal ◽  
Removal Rate ◽  
Domestic Wastewater ◽  
Metal Salts ◽  
Biological Aerated Filter ◽  
Mass Ratio ◽  
Aeration Intensity ◽  
Aerated Filter

Phosphorus removal by biological aerated filter(BAF) is ineffective, its effluent TP is much more than 0.5mg/L, so chemically enhanced phosphorus removal is neccessary. To solve this problem, domestic wastewater through BAF by adding metal salts in the aerobic tank was studied. The ferric chloride and aluminum chloride were chosen as the metal salts. The results showed that: the removal rate of TP rose with the Me/P (Me=Fe, Al)mass ratio increased, the influence on other performance of BAF by chemically enhanced synchronously was not severe, with TP in the effluent below the standard of 0.5mg/L; to ensure the concentration of effluent TP was less than 0.5mg/L, the optimum mass ratios of dosing were Fe/P=3, Al/P=2.5; proper aeration intensity could maintain the proper micro-flocculation state in BAF, which was helpful to TP removal.

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