Granular iron oxide adsorbents to control natural organic matter and membrane fouling in ultrafiltration water treatment

Ultra-filtration technology has been increasingly used in drinking water treatment due to improvements in membrane performance and lowering of costs. However, membrane fouling is the main limitation in the application of ultra-filtration technology. In this study, we investigated the impact of four different pre-treatments: Coagulation, adsorption, coagulation followed by adsorption (C-A), and simultaneous coagulation and adsorption (C+A), on membrane fouling and natural organic matter removal efficiency. The results showed that adsorption process required a large amount of adsorbent and formed a dense cake layer on the membrane surface leading to severe membrane fouling. Compared to adsorption alone, the coagulation and C-A processes decreased the transmembrane pressure by 4.9 kPa. It was due to less accumulation of particles on the membrane surface. As for water quality, the C-A ultra-filtration process achieved the highest removal efficiencies of natural organic matter and disinfection by-product precursors. Therefore, the addition of adsorbent after coagulation is a potentially important approach for alleviating ultra-filtration membrane fouling and enhancing treatment performance.

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Removal of natural organic matter using iron oxide-coated membrane systems

Water Science & Technology Water Supply ◽

10.2166/ws.2004.0110 ◽

2004 ◽

Vol 4 (5-6) ◽

pp. 207-213 ◽

Cited By ~ 5

Author(s):

K.-H. Choo ◽

I.-H. Park ◽

S.-J. Choi

Keyword(s):

Organic Matter ◽

Iron Oxide ◽

Natural Organic Matter ◽

Membrane Fouling ◽

Close Association ◽

Membrane Surface ◽

Oxide Particle ◽

Drinking Water Treatment ◽

Iron Oxide Particle ◽

Membrane Performance

Natural organic matter (NOM) removal and membrane fouling were investigated using iron oxide-coated microfiltration (MF) systems for drinking water treatment. Addition of iron oxide particle (IOP) adsorbents into MF always improved NOM removal and reduced fouling, but IOP dosing methods did affect the membrane performance. The IOP coating layer formed on the membrane surface played a major role in preventing membrane fouling by residual NOM in water. Pre-mixing of IOP with raw water followed by continuous injection into the MF system controlled membrane fouling better than pre- and intermittent loadings of IOP. This could be in close association with the distribution of IOPs across the hollow fiber MF surfaces and the effectiveness of contact of IOP with feedwater. The turbidity of water influenced the MF system with intermittent IOP loads more greatly than that with IOP in suspension. There existed an optimal IOP dose where membrane fouling can be minimized achieving maximal NOM removal.

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Effects of a Novel Adsorbent on Membrane Fouling by Natural Organic Matter in Drinking Water Treatment

Membranes ◽

10.3390/membranes9110151 ◽

2019 ◽

Vol 9 (11) ◽

pp. 151 ◽

Cited By ~ 3

Author(s):

Lelum Manamperuma ◽

Eilen Vik ◽

Mark Benjamin ◽

Zhenxiao Cai ◽

Jostein Skjefstad

Keyword(s):

Organic Matter ◽

Water Treatment ◽

Natural Organic Matter ◽

Membrane Fouling ◽

Treatment Plant ◽

Drinking Water Treatment ◽

Water Treatment Plant ◽

Water Source ◽

Packed Bed ◽

Transmembrane Pressure

Irreversible fouling of water filtration membranes reduces filter longevity and results in higher costs associated with membrane maintenance and premature replacement. The search for effective pretreatment methods to remove foulants that tend to irreversibly foul membranes is ongoing. In this study, a novel adsorbent (Heated Aluminum Oxide Particles (HAOPs)) was deployed in a fully automated pilot system to remove natural organic matter (NOM) from the surface water source used at the UniVann water treatment plant (WTP) in Ullensaker County, Norway. The pilot plant treatment process consists of passing the water through a thin layer of HAOPs that has been deposited on a mesh support. The HAOPs layer acts as an active packed bed which removes NOM from the water. Fluxes around 120 L/m2/h (LMH) at transmembrane pressure (TMP) below 10.7 psi (0.7 bar) were achieved over production cycles excessing 12 h. Treatment achieved always >85% colour removal and effluent colour <5 mg Pt/L (the target of treatment), and always <0.01 NTU turbidity and non-detectable suspended solids in the permeate. The HAOPs mixture after saturated with NOM is easy to remove by disruption of the HAOPs by rinsing the mesh surface, and the sludge is easily dewatered to higher of dry solids content.

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Preloading of GAC by natural organic matter in potable water treatment systems: Mechanisms, effects and design considerations

Journal of Water Supply Research and Technology—AQUA ◽

10.2166/aqua.2004.0037 ◽

2004 ◽

Vol 53 (7) ◽

pp. 469-482 ◽

Cited By ~ 5

Author(s):

Walter J. Weber

Keyword(s):

Organic Matter ◽

Water Treatment ◽

Natural Organic Matter ◽

Potable Water ◽

Design Considerations ◽

Potable Water Treatment

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

Water Science & Technology Water Supply ◽

10.2166/ws.2004.0111 ◽

2004 ◽

Vol 4 (5-6) ◽

pp. 215-222 ◽

Cited By ~ 2

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.

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