Membrane filtration of surface water in the presence of ozone

2001 ◽  
Vol 1 (5-6) ◽  
pp. 141-150 ◽  
Author(s):  
S. Sawada ◽  
I. Sumida ◽  
K. Matsumoto
Keyword(s):  
Organic Matter ◽  
Activated Carbon ◽  
Humic Acid ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Dominant Factor ◽  
Stable Operation ◽  
Raw Water ◽  
Pre Treatment

The preliminary study investigated the effect of pre-ozonation of synthetic raw water (bentonite and humic acid) on membrane fouling. The results showed that humic acid, not bentonite, was the dominant factor in membrane fouling. When the synthetic raw water was pre-treated using ozone and activated carbon, stable operation was possible at twice the flux of membrane filtration without pre-treatment. Thus, ozone and activated carbon reduced the concentration of organic matter (humic acid), leading to an increase in flux. Secondly, an MF membrane filtration device with ozone tolerance was attached downstream of the ozone reactor so that residual ozone could reach the membrane surface. When water was treated with MF membrane filtration in the presence of ozone, the flux was stable at 4 m/d. The membrane filtration resistance increased when ozone was not injected, and decreased when it was injected. This phenomenon was repeatable. In the presence of ozone, organic matter that could accelerate fouling as decomposed and converted to less fouled materials, resulting in a suppression of fouling as well as facilitating removal of the fouling layer during back washing.

Low-pressure membrane filtration with unconventional coagulation regimes

2005 ◽  
Vol 5 (5) ◽  
pp. 1-8 ◽  
Author(s):  
K.Y. Choi ◽  
B.A. Dempsey
Keyword(s):  
Activated Carbon ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Cross Flow ◽  
Chemical Cleaning ◽  
Sand Filters ◽  
Charge Neutralization ◽  
Floc Size ◽  
Filtration System ◽  
Pre Treatment

The objective of the research was to evaluate in-line coagulation to improve performance during ultrafiltration (UF). In-line coagulation means use of coagulants without removal of coagulated solids prior to UF. Performance was evaluated by removal of contaminants (water quality) and by resistance to filtration and recovery of flux after hydraulic or chemical cleaning (water production). We hypothesized that coagulation conditions inappropriate for conventional treatment, in particular under-dosing conditions that produce particles that neither settle nor are removed in rapid sand filters, would be effective for in-line coagulation prior to UF. A variety of pre-treatment processes for UF have been investigated including coagulation, powdered activated carbon (PAC) or granular activated carbon (GAC), adsorption on iron oxides or other pre-formed settleable solid phases, or ozonation. Coagulation pre-treatment is often used for removal of fouling substances prior to NF or RO. It has been reported that effective conventional coagulation conditions produced larger particles and this reduced fouling during membrane filtration by reducing adsorption in membrane pores, increasing cake porosity, and increasing transport of foulants away from the membrane surface. However, aggregates produced under sweep floc conditions were more compressible than for charge neutralization conditions, resulting in compaction when the membrane filtration system was pressurized. It was known that the coagulated suspension under either charge-neutralization or sweep floc condition showed similar steady-state flux under the cross-flow microfiltration mode. Another report on the concept of critical floc size suggested that flocs need to reach a certain critical size before MF, otherwise membranes can be irreversibly clogged by the coagulant solids. The authors were motivated to study the effect of various coagulation conditions on the performance of a membrane filtration system.

Coagulation/flocculation/ultrafiltration for natural organic matter removal in drinking water production

2004 ◽  
Vol 4 (5-6) ◽  
pp. 215-222 ◽  
Author(s):  
A.R. Costa ◽  
M.N. de Pinho
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Water Production ◽  
Cellulose Acetate Membranes ◽  
Wide Range ◽  
Drinking Water Production

Membrane fouling by natural organic matter (NOM), namely by humic substances (HS), is a major problem in water treatment for drinking water production using membrane processes. Membrane fouling is dependent on membrane morphology like pore size and on water characteristics namely NOM nature. This work addresses the evaluation of the efficiency of ultrafiltration (UF) and Coagulation/Flocculation/UF performance in terms of permeation fluxes and HS removal, of the water from Tagus River (Valada). The operation of coagulation with chitosan was evaluated as a pretreatment for minimization of membrane fouling. UF experiments were carried out in flat cells of 13.2×10−4 m2 of membrane surface area and at transmembrane pressures from 1 to 4 bar. Five cellulose acetate membranes were laboratory made to cover a wide range of molecular weight cut-off (MWCO): 2,300, 11,000, 28,000, 60,000 and 75,000 Da. Severe fouling is observed for the membranes with the highest cut-off. In the permeation experiments of raw water, coagulation prior to membrane filtration led to a significant improvement of the permeation performance of the membranes with the highest MWCO due to the particles and colloidal matter removal.

Characteristics of coagulation-flocculation of humic acid with effective performance of polymeric flocculant and inorganic coagulant

2003 ◽  
Vol 47 (1) ◽  
pp. 89-95 ◽  
Author(s):  
J. Yu ◽  
D.D. Sun ◽  
J.H. Tay
Keyword(s):  
Humic Acid ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Molecular Size ◽  
Aluminium Sulphate ◽  
Fouling Control ◽  
Effective Performance ◽  
Water And Wastewater ◽  
Pre Treatment ◽  
Flocculation Process

Ferric chloride and aluminium sulphate as coagulants and positive charged flocculants PDDMAC ((PDDMAC = poly (diallyldimethylammonium chloride) were used for pre-treatment of water and wastewater for removing humic substance prior to RO membrane filtration. It was found that a combination of flocculant and coagulant enhanced the coagulation-flocculation process and humic acid removal. The optimum conditions of coagulation-flocculation were established in reference to the ratio of humic acid and coagulant. Zeta potential and the ratio of E4/E6 were investigated to explore the possible micro-mechanisms of coagulation-flocculation. The ratios of E4/E6 show the molecular size variations using different coagulants and flocculants, which are expected to benefit membrane-fouling control.

scholarly journals Effects of Ferrihydrite-Impregnated Powdered Activated Carbon on Phosphate Removal and Biofouling of Ultrafiltration Membrane

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1178
Author(s):  
Jenyuk Lohwacharin ◽  
Thitiwut Maliwan ◽  
Hideki Osawa ◽  
Satoshi Takizawa
Keyword(s):  
Activated Carbon ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Powdered Activated Carbon ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Surface Water Treatment ◽  
Filtration System ◽  
Pore Blockage

The presence of multiple contaminant species in surface waters makes surface water treatment difficult to accomplish through a single process. Herein, we evaluated the ability of an integrated adsorption/ultrafiltration (UF) membrane filtration system to simultaneously remove phosphates and dissolved organic matter (DOM). When bare powdered activated carbon (PAC) and PAC impregnated with amorphous ferrihydrite (FHPAC) adsorbents were compared, FHPAC showed a greater adsorption rate and capacity for phosphate. FHPAC had a phosphate adsorption capacity of 2.32 mg PO43−/g FHPAC, even when DOM was present as a competing adsorbate. In a lab-scale hybrid FHPAC-UF system (i.e. integrated adsorption by FHPAC with UF membrane filtration), irreversible membrane fouling was ca. three times lower than that in a PAC-UF system. When membrane fouling in the PAC-UF system was described with pore blockage models, we found that the main cause of fouling was bacterial deposition on the membrane surface. CLSM analysis determined that the chemical composition of foulants in the PAC-UF system included higher proportions of proteins, nucleic acids, and alpha-polysaccharides than that in the FHPAC-UF system. Overall, FHPAC’s ability to undergo ligand exchanges with DOM helped to reduce the nutrients and bacteria that cause biofouling to accumulate on the membrane surface.

scholarly journals The membrane fouling mechanisms of the PAC/BPAC-UF combined process used to treat the secondary effluent from municipal wastewater treatment plant

2017 ◽  
Vol 77 (1) ◽  
pp. 211-219 ◽  
Author(s):  
Lihua Sun ◽  
Ning He ◽  
Xi Duan ◽  
Bingbing Yang ◽  
Cuimin Feng ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Activated Carbon ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Membrane Surface ◽  
Treatment Plant ◽  
Powdered Activated Carbon ◽  
Combined Processes ◽  
Secondary Effluent

Abstract The combined processes of powdered activated carbon/biological powdered activated carbon- ultrafiltration (PAC/BPAC-UF) were used to treat secondary effluent. In this study, the effect of PAC and BPAC on membrane flux, membrane resistance and the removal of different molecular weight organic compounds were investigated. In addition, the structure characteristics of the microorganisms of the BPAC were analyzed. The results showed that the optimum dosage of PAC and BPAC was 10 mg/L and 40 mg/L respectively. The reversible membrane fouling resistance of BPAC-UF was higher than that of PAC-UF, and the two processes had the least irreversible resistance at the best dosage. The biodegradation of BPAC increased the concentration of small molecular weight organic matter up to 10,000 Da in the membrane effluent. So the dissolved organic carbon (DOC) removal effect of BPAC-UF process worsened. Microorganisms such as Proteobacteria, Bacteroidetes, Planctomycetes and other microorganisms on the surface of the BPAC enhanced the removal of organic matter in water. The results of scanning electron microscopy (SEM) scans showed that there was net mucus membrane on the UF membrane surface before the backwashing of the BPAC-UF process which increased the proportion of reversible pollution resistance. The physical flushing effect of BPAC-UF was better than that of direct UF and PAC-UF processes.

scholarly journals Development of Magnetite Nano–composite Membrane for Membrane Defouling

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
N. A. Azmi ◽  
Q. H. Ng ◽  
A. L. Ahmad ◽  
S. C. Low
Keyword(s):  
Humic Acid ◽  
Composite Membrane ◽  
Membrane Fouling ◽  
Electrostatic Interactions ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Ammonium Hydroxide ◽  
Polymeric Membrane ◽  
Precipitation Method ◽  
Nano Composite

This research proposes to untangle the membrane fouling by introducing nanostructured magnetite (Fe3O4) colloids into the polymeric membrane. In present study, nanostructure magnetite nanoparticles (MNPs) were synthesized via co–precipitation method with ammonium hydroxide and sodium hydroxide as the precipitation agents at different pH condition. The synthesized MNPs were functionalized with poly(diallyldimethylammonium chloride) (PDDA) and then spin coated on the surface of the ultrafiltration cellulose acetate (CA) membrane. Intrinsic properties for this nano–composite membrane, in regards to the physical structures, surface negative charge density and the membrane filtration performance, on surface fouling by humic acid solutions were investigated. Experimental results demonstrated that, the nano–composite membrane has significantly reduced the humic acid fouling on the membrane surface. This could be explained by the electrostatic interactions between negatively charged humic acid molecules and the nano–composite membrane. Throughout the study, the results provide some fundamental insights into the physical interactions that governing the membrane fouling during filtration.

Household rainwater harvesting system – pilot scale gravity driven membrane-based filtration system

2013 ◽  
Vol 13 (3) ◽  
pp. 790-797 ◽  
Author(s):  
B. Kus ◽  
Jaya Kandasamy ◽  
S. Vigneswaran ◽  
H. K. Shon ◽  
G. Moody
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Organic Matter ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Rainwater Harvesting ◽  
Membrane Filter ◽  
Pilot Scale ◽  
Treatment System ◽  
Pre Treatment

This paper presents the results of a pilot scale study consisting of pre-treatment with a granular activated carbon (GAC) filter followed by membrane filtration. Detailed characterisation of rainwater tanks has highlighted that turbidity, dissolved organic carbon (DOC) and heavy metals, in particular lead, were not compliant with the 2004 Australian Drinking Water Guidelines (ADWG). Further, organic matter present in the water causes membrane fouling and leads to carcinogenic compounds upon chlorination. A GAC filter was used as a first step to remove dissolved organic matter (measured in terms of DOC) in particular and also to reduce the concentration, of turbidity and lead. Membrane filtration can remove any remaining solids reducing the concentrations of turbidity and microorganisms. In this study a pilot scale rainwater treatment system consisting of a gravity fed GAC filter and membrane filter (Ultra Flo) was operated for a period of 120 days. The performance of this system was assessed in terms of membrane flux and improvement in water quality measured against the 2004 Australian Drinking Water Guidelines. Determination of the flux especially in the later stages of membrane operation was important to be able to size the filters in a manner that meets the expected demand. The treatment system of GAC filter and membrane filter was effective in reducing the turbidity, DOC and heavy metals. The system reduced the turbidity to levels of 0.3–0.4 NTU, below the ADWG limit of 1 NTU. The concentration of DOC was reduced to below the 2004 Australian Drinking Water Guidelines limit of 0.2 mg/L. The concentration of lead was reduced to less than 0.005 mg/L, and below the ADWD limit of 0.01 mg/L. The concentrations of all other heavy metals were well within the ADWG limits. Further, the GAC filter removed a majority of the organic substances from raw rainwater collected from the roof. After the initial flux decline, the stable flux achieved was 0.47 L/m2/h consistently over the final 60 days of the experiment.

scholarly journals Comparative environmental impact evaluation using life cycle assessment approach: a case study of integrated membrane-filtration system for the treatment of aerobically-digested palm oil mill effluent

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Yeit Haan Teow ◽  
Meng Teck Chong ◽  
Kah Chun Ho ◽  
Abdul Wahab Mohammad
Keyword(s):  
Activated Carbon ◽  
Life Cycle ◽  
Palm Oil ◽  
Membrane Filtration ◽  
Electricity Consumption ◽  
Sand Filters ◽  
Unit Operations ◽  
Filtration System ◽  
Pre Treatment ◽  
Aerobically Digested

AbstractAiming to mitigate wastewater pollution arising from the palm oil industry, this university-industry research-and-development project focused on the integration of serial treatment processes, including the use of moving bed biofilm reactor (MBBR), pre-treatment with sand filters and activated carbon filters, and membrane technology for aerobically-digested palm oil mill effluent (POME) treatment. To assess the potential of this sustainable alternative practice in the industry, the developed technology was demonstrated in a pilot-scale facility: four combinations (Combinations I to IV) of unit operations were developed in an integrated membrane-filtration system. Combination I includes a MBBR, pre-treatment unit comprising sand filters and activated carbon filters, ultrafiltration (UF) membrane, and reverse osmosis (RO) membrane, while Combination II excludes MBBR, Combination III excludes UF membrane, and Combination IV excludes both MBBR and UF membrane. Life cycle assessment (LCA) was performed to evaluate potential environmental impacts arising from each combination while achieving the goal of obtaining recycled and reusable water from the aerobically-digested POME treatment. It is reported that electricity consumption is the predominant factor contributing to most of those categories (50–77%) as the emissions of carbon dioxide (CO2), sulfur dioxide (SO2), nitrogen oxides, and volatile mercury during the combustion of fossil fuels. Combination I in the integrated membrane-filtration system with all unit operations incurring high electricity consumption (52 MJ) contributed to the greatest environmental impact. Electricity consumption registers the highest impact towards all life cycle impact categories: 73% on climate change, 80% on terrestrial acidification, 51% on eutrophication, and 43% on human toxicity. Conversely, Combination IV is the most environmentally-friendly process, since it involves only two-unit operations – pre-treatment unit (comprising sand filters and activated carbon filters) and RO membrane unit – and thus incurs the least electricity consumption (41.6 MJ). The LCA offers insights into each combination of the operating process and facilitates both researchers and the industry towards sustainable production.

scholarly journals Pilot Study on the Combination of Different Pre-Treatments with Nanofiltration for Efficiently Restraining Membrane Fouling While Providing High-Quality Drinking Water

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 380
Author(s):  
Yan Chen ◽  
Huiping Li ◽  
Weihai Pang ◽  
Baiqin Zhou ◽  
Tian Li ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Post Treatment ◽  
Size Exclusion ◽  
Transmembrane Pressure ◽  
Feed Water ◽  
High Quality ◽  
Treated Water

Nanofiltration (NF) is a promising post-treatment technology for providing high-quality drinking water. However, membrane fouling remains a challenge to long-term NF in providing high-quality drinking water. Herein, we found that coupling pre-treatments (sand filtration (SF) and ozone–biological activated carbon (O3-BAC)) and NF is a potent tactic against membrane fouling while achieving high-quality drinking water. The pilot results showed that using SF+O3-BAC pre-treated water as the feed water resulted in a lower but a slowly rising transmembrane pressure (TMP) in NF post-treatment, whereas an opposite observation was found when using SF pre-treated water as the feed water. High-performance size-exclusion chromatography (HPSEC) and three-dimensional excitation–emission matrix (3D-EEM) fluorescence spectroscopy determined that the O3-BAC process changed the characteristic of dissolved organic matter (DOM), probably by removing the DOM of lower apparent molecular weight (LMW) and decreasing the biodegradability of water. Moreover, amino acids and tyrosine-like substances which were significantly related to medium and small molecule organics were found as the key foulants to membrane fouling. In addition, the accumulation of powdered activated carbon in O3-BAC pre-treated water on the membrane surface could be the key reason protecting the NF membrane from fouling.

scholarly journals Influential Mechanism of Natural Organic Matters with Calcium Ion on the Anion Exchange Membrane Fouling Behavior via xDLVO Theory

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 968
Author(s):  
Zhun Ma ◽  
Lu Zhang ◽  
Ying Liu ◽  
Xiaosheng Ji ◽  
Yuting Xu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Interaction Energy ◽  
Anion Exchange ◽  
Natural Organic Matter ◽  
Calcium Ions ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Anion Exchange Membrane ◽  
Anion Exchange Membranes ◽  
Exchange Membrane

The fouling mechanism of the anion exchange membrane (AEM) induced by natural organic matter (NOM) in the absence and presence of calcium ions was systematically investigated via the extended Derjaguin–Landau–Verwey–Overbeek (xDLVO) approach. Sodium alginate (SA), humic acid (HA), and bovine serum albumin (BSA) were utilized as model NOM fractions. The results indicated that the presence of calcium ions tremendously aggravated the NOM fouling on the anion exchange membrane because of Ca-NOM complex formation. Furthermore, analysis of the interaction energy between the membrane surface and foulants via xDLVO revealed that short-range acid–base (AB) interaction energy played a significant role in the compositions of interaction energy during the electrodialysis (ED) process. The influence of NOM fractions in the presence of calcium ions on membrane fouling followed the order: SA > BSA > HA. This study demonstrated that the interaction energy was a dominating indicator for evaluating the tendency of anion exchange membranes fouling by natural organic matter.

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