Effect of pre-coagulation on mitigating irreversible fouling during ultrafiltration of a surface water

2005 ◽  
Vol 51 (6-7) ◽  
pp. 93-100 ◽  
Author(s):  
K. Kimura ◽  
Y. Hane ◽  
Y. Watanabe
Keyword(s):  
Molecular Weight ◽  
Surface Water ◽  
Water Purification ◽  
Membrane Fouling ◽  
Pilot Scale ◽  
Organic Substances ◽  
Chemical Cleaning ◽  
Membrane Unit ◽  
Pre Treatment ◽  
Purification Plant

Membrane fouling can be divided into two types: reversible fouling and irreversible fouling. The former can be easily canceled by physical cleaning (e.g., backwashing) while the latter needs chemical cleaning to be mitigated. For more efficient use of membranes, the control of irreversible membrane fouling is of importance. In this study, the effectiveness of pre-coagulation/sedimentation on irreversible membrane fouling was investigated, based on the pilot-scale operation of the membrane unit installed at an existing water purification plant. The membrane employed was a low-pressure ultrafiltration (UF) membrane made of polysulfone and having a molecular weight cut-off of 750,000 daltons. Although pre-coagulation/sedimentation significantly mitigated membrane fouling mainly through the reduction of reversible membrane fouling, the degree of irreversible fouling was not reduced by the pre-treatment. This was because the irreversible fouling observed during this study was mainly attributed to polysaccharides/protein like fractions of organic substances that cannot be efficiently removed by coagulation/sedimentation. Aluminium used as coagulant was thought to cause irreversible fouling to some extent but did not in the pilot operation, which could probable be explained by the fact that coagulation was conducted at relatively high pH (7.0) in this study.

Pilot scale evaluation of biofiltration as an innovative pre-treatment for ultrafiltration membranes for drinking water treatment

2011 ◽  
Vol 11 (1) ◽  
pp. 23-29 ◽  
Author(s):  
P. M. Huck ◽  
S. Peldszus ◽  
C. Hallé ◽  
H. Ruiz ◽  
X. Jin ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Membrane Fouling ◽  
Drinking Water Treatment ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Membrane Unit ◽  
Ozone Addition ◽  
Pre Treatment ◽  
Uf Membranes

Fouling remains one of the major constraints on the use of low pressure membranes in drinking water treatment. Work over the last few years has shown the importance of biopolymers (carbohydrates and protein-like material) as foulants for ultrafiltration (UF) membranes. The purpose of this study was to investigate at pilot scale the use of rapid biofiltration (without prior coagulation or ozone addition) as an innovative pretreatment to reduce fouling of UF membranes. The investigation was carried out on a water with a higher than average DOC and significant temperature variation. The biofilters, each operated at a hydraulic loading of 5 m/h, had empty bed contact times of 5, 10 and 15 minutes. The membrane unit was operated at a flux equivalent to 60 LMH at 20°C. The investigation confirmed the encouraging results obtained in an earlier smaller scale study with essentially the same water. Increased biofiltration contact time (i.e. increased bed depth) led to lower rates of hydraulically irreversible fouling. The initial biofiltration backwash procedure, involving air scour as is common in chemically assisted filtration, led in some cases to an increased rate of membrane fouling immediately after the backwash. An alternative backwashing strategy was developed, however the feasibility of operating with this approach over very long periods of time needs to be confirmed. To assist in full-scale implementation of this “green” and simple pretreatment, the design and operating conditions for the biofilters should be optimized for various types of waters. It is expected that biofiltration pretreatment will be of particular interest for small and/or isolated systems where a higher initial capital cost may be acceptable because of operational simplicity and reduced chemical requirements.

Nanofiltration of colored surface water: Quebec's experience

2003 ◽  
Vol 3 (5-6) ◽  
pp. 15-22
Author(s):  
P. Kouadio ◽  
M. Tétrault
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Membrane Fouling ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Quebec City ◽  
Water Regulation ◽  
Eastern Canada

Three colored surface water nanofiltration pilot-scale projects were conducted in the province of Quebec (eastern Canada), between November 2000 and March 2002, by the company H2O Innovation (2000) inc., for the municipalities of Lac Bouchette, Latulipe-et-Gaboury and Charlesbourg (now part of Quebec City). Results indicated that nanofiltration permeate quality has an advance on present drinking water regulation standard in Quebec, but important membrane fouling occurred. Fouling can be controlled by pretreatment and optimization of the operating conditions.

Treatment of highly-colored surface water by a hybrid microfiltration membrane system incorporating ion-exchange

2018 ◽  
Vol 19 (3) ◽  
pp. 855-863 ◽  
Author(s):  
T. Miyoshi ◽  
Y. Takahashi ◽  
T. Suzuki ◽  
R. Nitisoravut ◽  
C. Polprasert
Keyword(s):  
Surface Water ◽  
Hybrid System ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane System ◽  
Pilot Scale ◽  
Manganese Concentration ◽  
Moderate Increase ◽  
Coagulant Dosage ◽  
Filtration System

Abstract This study investigated the performance of a hybrid membrane filtration system to produce industrial water from highly-colored surface water. The system consists of a membrane filtration process with appropriate pretreatments, including coagulation, pre-chlorination, and anion exchange (IE) process. The results of the pilot-scale experiments revealed that the hybrid system can produce treated water with color of around 5 Pt-Co, dissolved manganese concentration of no more than 0.05 mg/L, and a silt density index (SDI) of no more than 5 when sufficient coagulant and sodium hypochlorite were dosed. Although the IE process effectively reduced the color of the water, a moderate increase in the color of the IE effluent was observed when there was a significant increase in the color of the raw water. This resulted in a severe membrane fouling, which was likely to be attributed to the excess production of inorganic sludge associated with the increased coagulant dosage required to achieve sufficient reduction of color. Such severe membrane fouling can be controlled by optimising the backwashing and relaxation frequencies during the membrane filtration. These results indicate that the hybrid system proposed is a suitable technology for treating highly-colored surface water.

scholarly journals Removal Characteristics of N-Nitrosamines and Their Precursors by Pilot-Scale Integrated Membrane Systems for Water Reuse

2018 ◽  
Vol 15 (9) ◽  
pp. 1960 ◽  
Author(s):  
Haruka Takeuchi ◽  
Naoyuki Yamashita ◽  
Norihide Nakada ◽  
Hiroaki Tanaka
Keyword(s):  
Membrane Fouling ◽  
Water Reuse ◽  
Pilot Scale ◽  
Feed Water ◽  
Water Reclamation ◽  
Size Distributions ◽  
Membrane Systems ◽  
Chemical Cleaning ◽  
Ro Membrane ◽  
Feed Water Temperature

This study investigated the removal characteristics of N-Nitrosamines and their precursors at three pilot-scale water reclamation plants. These plants applies different integrated membrane systems: (1) microfiltration (MF)/nanofiltration (NF)/reverse osmosis (RO) membrane; (2) sand filtration/three-stage RO; and (3) ultrafiltration (UF)/NF and UF/RO. Variable removal of N-Nitrosodimethylamine (NDMA) by the RO processes could be attributed to membrane fouling and the feed water temperature. The effect of membrane fouling on N-Nitrosamine removal was extensively evaluated at one of the plants by conducting one month of operation and chemical cleaning of the RO element. Membrane fouling enhanced N-Nitrosamine removal by the pilot-scale RO process. This finding contributes to better understanding of the variable removal of NDMA by RO processes. This study also investigated the removal characteristics of N-Nitrosamine precursors. The NF and RO processes greatly reduced NDMA formation potential (FP), but the UF process had little effect. The contributions of MF, NF, and RO processes for reducing FPs of NDMA, N-Nitrosopyrrolidine and N-Nitrosodiethylamine were different, suggesting different size distributions of their precursors.

scholarly journals Biologically active ion exchange (BIEX) for NOM removal and membrane fouling prevention

2017 ◽  
Vol 17 (4) ◽  
pp. 1178-1184 ◽  
Author(s):  
M. Schulz ◽  
J. Winter ◽  
H. Wray ◽  
B. Barbeau ◽  
P. Bérubé
Keyword(s):  
Molecular Weight ◽  
Biological Activity ◽  
Ion Exchange ◽  
Membrane Fouling ◽  
Building Blocks ◽  
Biologically Active ◽  
Low Molecular Weight ◽  
Effective Removal ◽  
Pre Treatment ◽  
The Impact

The natural organic matter (NOM) removal efficiency and regeneration behavior of ion-exchange filters with promoted biological activity (BIEX) was compared to operation where biological activity was suppressed (i.e. abiotic conditions). The impact of BIEX pre-treatment on fouling in subsequent ultrafiltration was also investigated. Biological operation enhanced NOM removal by approximately 50% due to an additional degradation of smaller humic substances, building blocks and low molecular weight acids. Promotion of biological activity significantly increased the time to breakthrough of the filters and, therefore, is expected to lower the regeneration frequency as well as the amount of regenerate of which to dispose. Pre-treatment using BIEX filters resulted in a significant decrease in total and irreversible fouling during subsequent ultrafiltration. The decrease was attributed to the effective removal of medium and low molecular weight NOM fractions. The results indicate that BIEX filtration is a robust, affordable and easy-to-operate pre-treatment approach to minimize fouling in ultrafiltration systems and enhance the quality of the produced permeate.

Identifying Membrane Foulants in Chemical Cleaning Solutions

2013 ◽  
Vol 726-731 ◽  
pp. 1872-1878 ◽  
Author(s):  
Jun Xia Liu ◽  
Bing Zhi Dong ◽  
Yun Ge Sheng ◽  
Ji Ping Wang
Keyword(s):  
Molecular Weight ◽  
Metal Ions ◽  
Membrane Fouling ◽  
Chemical Cleaning ◽  
Organic Matters ◽  
Main Metal ◽  
Acid Cleaning ◽  
Chemical Agents ◽  
Natural Organic Matters ◽  
Hydrophobic Acids

The main objective of this study was to investigate foulants in chemical cleaning solutions of membrane (CCSM). Sodium hydroxide (NaOH), sodium hypochlorite (NaOCl), hydrochloric acid (HCl) were used as chemical agents respectively. Hydrophobicity, molecular weight distribution and metal ions of foulants in CCSM were analyzed as the major characters for membrane fouling. Results reveal that alkali cleaning can remove both hydrophobic and hydrophilic fractions of natural organic matters (NOM), and acid cleaning mainly removes hydrophilic organic matters. Medium molecular weight of very hydrophobic acids (1-10 kDa) and different molecular weight of neutral hydrophilic acids (100-1000 Da & >300kDa) in NOM can lead to membrane irreversible fouling. Acid cleaning is relatively effective for the reduction of inorganic foulants. The main metal ions in acid cleaning solutions are K ,Ca, Al and Mn, which are responsible for membrane inorganic fouling.

scholarly journals Enhanced Removal of Organic Pollutants and Reactive Dye in Polyethersulfone Submerged Membrane Bioreactor (PES-SMBR) for Textile Wastewater

2021 ◽  
Vol 16 (1) ◽  
pp. 329-341
Author(s):  
Tukaram P. Chavan ◽  
Ganpat B. More ◽  
Sanjaykumar R. Thorat
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Textile Wastewater ◽  
Pilot Scale ◽  
Reactive Dye ◽  
Hollow Fibre ◽  
Flow Mode ◽  
Permeate Flux ◽  
Chemical Cleaning ◽  
Submerged Membrane Bioreactor

The present investigation was carried out to assess the operation of a pilot-scale submerged membrane bioreactor (SMBR) for the treatment of reactive dye and textile wastewater. The operation of SMBR model was conducted by using a polyethersulfone (PES) hollow fibre membrane with continuous flow mode at different HRTs at 8, 6 and 4 h, for 90 days. During the entire operation, the average permeate flux, TMP, F/M ratio and OLR was found to be 19 (L/m²/h), 2.6 (psi), 0.10 (g BOD/(g MLSS•d) and 0.89 (kg BOD/m³.d), respectively. The variations in the permeate flux, TMP, F/M ratio and OLR have not adversely effects on the operation of the SMBR model. Throughout the entire operation, despite the TP, TDS and conductivity, the high amount of COD (82%), BOD (86%), NO3-N (79%), TSS (98%), turbidity (97%) and colour (79%), removal was achieved. The permeate flux was declined by membrane fouling and it was recovered by chemical cleaning as well as regular backwashing during the entire operation. The results obtained from the study concluded that the hollow fibre ultrafiltration polyethersulfone (PES) membrane shows good performance while treating textile wastewater along with reactive dye solution.

Performance and membrane foulant in the pilot operation of a novel biofilm-membrane reactor

2002 ◽  
Vol 2 (2) ◽  
pp. 177-183
Author(s):  
K. Kimura ◽  
Y. Watanabe
Keyword(s):  
Membrane Fouling ◽  
Membrane Reactor ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
Manganese Concentration ◽  
Membrane Cleaning ◽  
Chemical Washing ◽  
Pre Treatment ◽  
Solid Liquid ◽  
Solid Liquid Separation

We have developed a novel biofilm-membrane reactor (BMR) in which a nitrifying biofilm is fixed on the surface of a rotating membrane disk. With this reactor, both strict solid-liquid separation and oxidation of ammonia nitrogen can be simultaneously performed. Based on the results obtained in previous bench-scale experiments, a pilot-scale study was conducted using river water at a water purification plant. The results obtained in the pilot study can be summarized as follows. (1) By implementation of pre-treatment (coagulation and sedimentation) and simple membrane cleaning (sponge cleaning), the filter run could be continued for 17 months without any chemical washing. (2) Sufficient nitrification was observed when water temperature was high. Deterioration in nitrification efficiency during winter was reduced by the addition of phosphorus. (3) In addition to nitrification, biological oxidation of AOC and manganese can be expected with the BMR. In this study, both AOC and manganese concentration in the permeate decreased to a level less than 10 μg/L. (4) Irreversible membrane fouling, which was thought to be mainly caused by manganese, became significant as the operation period became longer.

scholarly journals Characteristics of membrane fouling by consecutive chemical cleaning in pressurized ultrafiltration as pre-treatment of seawater desalination

Desalination ◽  
2015 ◽  
Vol 369 ◽  
pp. 51-61 ◽  
Author(s):  
Yun Chul Woo ◽  
Jeong Jun Lee ◽  
Leonard D. Tijing ◽  
Ho Kyong Shon ◽  
Minwei Yao ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Seawater Desalination ◽  
Chemical Cleaning ◽  
Pre Treatment

scholarly journals Assessing pre-adsorption time impact on ultrafiltration performance for surface water treatment

2017 ◽  
Vol 18 (3) ◽  
pp. 950-955
Author(s):  
Bo Gui ◽  
Qingqing Zhao ◽  
Junxia Liu ◽  
Zhihong Wang ◽  
Huaqiang Chu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Liquid Chromatography ◽  
Activated Carbon ◽  
Water Treatment ◽  
Surface Water ◽  
Membrane Fouling ◽  
Low Molecular Weight ◽  
Raw Water ◽  
Adsorption Time ◽  
Surface Water Treatment

Abstract This study was to assess the effect of powdered activated carbon (PAC) pre-adsorption time on ultrafiltration performance for surface water treatment. Experimental results demonstrated that membrane fouling could be mitigated by extending the pre-adsorption time. The molecular weight (MW) distribution of water samples was determined by liquid chromatography – organic carbon detector (LC-OCD) and results showed that the mechanism of PAC controlling fouling was attributed to a decrease in the low molecular weight (LMW) fraction of raw water via extending the pre-adsorption time. Fouling indexes (FIs) were used to evaluate membrane fouling potential and the results showed that polysaccharides (PS) and proteins (PN) were greatly responsible for membrane fouling. Therefore, prolonging the PAC pre-adsorption time and decreasing the PS and PN content in raw water are the main measurement for the alleviation of membrane fouling when PAC is used as the pretreatment in waterworks.

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