scholarly journals Investigations of the mechanism of the fouling in microgranular adsorptive filtration

2017 ◽  
Vol 35 (1) ◽  
pp. 137-140 ◽  
Author(s):  
Beata Malczewska
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Mathematical Models ◽  
Natural Organic Matter ◽  
Natural Water ◽  
Membrane Filtration ◽  
Underlying Mechanism ◽  
Constant Flow ◽  
Filtration System ◽  
Blocking Mechanism

Abstract The application of microgranular adsorptive filtration (μGAF) has been successfully used in conjunction with membrane filtration. It proves to be efficient not only in removal of natural organic matter (NOM) but also it significantly reduces the extent of fouling. There are a few mathematical models evaluated to understand the underlying mechanism of fouling. This paper describes a method of predicting filtration capacities using constant flow datasets collected when μGAF was applied. The results suggest that the behaviour of fouling in microgranular adsorptive filtration system varies between different filtration operations and natural water quality. In analysed case the mechanism of pores blocking can be described by the complete blocking mechanism.

Removal of natural organic matter - a fresh approach

2002 ◽  
Vol 2 (1) ◽  
pp. 71-79 ◽  
Author(s):  
M. Drikas ◽  
J.Y. Morran ◽  
C. Pelekani ◽  
C. Hepplewhite ◽  
D.B. Bursill
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Filtration ◽  
Distribution Systems ◽  
Adsorptive Capacity ◽  
High Concentration ◽  
Australian Water ◽  
Prime Concern ◽  
Exchange Resins

Natural organic matter (NOM) has been shown to be one of the major parameters that affects water quality and treatment processes. NOM reduces the effectiveness of water treatment by interfering with the flocculation process, makes treatment with activated carbon and membrane filtration less efficient and is a precursor to the formation of disinfectant by-products (DBP). Furthermore, NOM acts as a food source for micro-organisms resulting in bacterial regrowth in distribution systems. These concerns have resulted in the removal of NOM from raw water being of prime concern for water authorities. The elevated levels of NOM in Australian water supplies have resulted in priority being given to research into methods of removing NOM by the Australian Water Quality Centre (AWQC). Early work showed that some types of anion exchange resins were very effective for NOM removal and that while resin column systems were rapidly fouled by waters with high concentration of suspended matter, a stirred system had no such limitation. This lead to the development of a resin with a high adsorptive capacity for NOM by the Commonwealth Scientific & Industrial Research Organisation (CSIRO) in collaboration with the AWQC which will be manufactured under licence by Orica Australia Pty Ltd. This resin then formed the basis for a novel process for NOM removal developed by the AWQC in collaboration with Orica Australia Pty Ltd. Both the MIEX® resin and process have been patented internationally. This paper outlines the process, gives examples of some of the benefits and provides recent results from an operating pilot plant with a capacity 160 kL/day.

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.

scholarly journals Natural organic matter removal by ion exchange at different positions in the drinking water treatment lane

2013 ◽  
Vol 6 (1) ◽  
pp. 1-10 ◽  
Author(s):  
A. Grefte ◽  
M. Dignum ◽  
E. R. Cornelissen ◽  
L. C. Rietveld
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Drinking Water Treatment ◽  
Biological Stability ◽  
Sand Filtration ◽  
Slow Sand Filtration

Abstract. To guarantee a good water quality at the customers tap, natural organic matter (NOM) should be (partly) removed during drinking water treatment. The objective of this research was to improve the biological stability of the produced water by incorporating anion exchange (IEX) for NOM removal. Different placement positions of IEX in the treatment lane (IEX positioned before coagulation, before ozonation or after slow sand filtration) and two IEX configurations (MIEX® and fluidized IEX (FIX)) were compared on water quality as well as costs. For this purpose the pre-treatment plant at Loenderveen and production plant Weesperkarspel of Waternet were used as a case study. Both, MIEX® and FIX were able to remove NOM (mainly the HS fraction) to a high extent. NOM removal can be done efficiently before ozonation and after slow sand filtration. The biological stability, in terms of assimilable organic carbon, biofilm formation rate and dissolved organic carbon, was improved by incorporating IEX for NOM removal. The operational costs were assumed to be directly dependent of the NOM removal rate and determined the difference between the IEX positions. The total costs for IEX for the three positions were approximately equal (0.0631 € m−3), however the savings on following treatment processes caused a cost reduction for the IEX positions before coagulation and before ozonation compared to IEX positioned after slow sand filtration. IEX positioned before ozonation was most cost effective and improved the biological stability of the treated water.

scholarly journals Self forming dynamic membrane filtration for drinking water treatment

2021 ◽  
Author(s):  
Suna Ozden Celik ◽  
Nese Tufekci ◽  
Ismail Koyuncu
Keyword(s):  
Organic Matter ◽  
Iron Oxide ◽  
Natural Water ◽  
Membrane Filtration ◽  
Drinking Water Treatment ◽  
Limit Values ◽  
Remarkable Effect ◽  
Alternative Treatment Option ◽  
Dynamic Membranes ◽  
Synthetic Water

Abstract Lab-scale continuous operation of self forming MF and UF dynamic membranes were investigated simultaneously by applying iron oxide as an alternative treatment option in those waters having natural organic matter (NOM), iron and manganese. Both dynamic membranes gave high removal rates and effluent concentrations of pollutants were below the limit values in synthetic water. 60–62% of DOC and 75–78% of UV254 were removed in low DOC synthetic water (LS) by MF and UF dynamic membranes, respectively. Although only 42–49% of DOC and 48–53% of UV254 could be removed by MF and UF dynamic membranes, remarkable effect on fouling alleviation was observed in high DOC synthetic water (HS). Iron oxide did not enhance the removal of organic matter in low DOC natural water (LN) as much as it did in synthetic water. Iron oxide led to the removal of high molecular weight organics, thus reversible fouling reduced almost 2 orders of magnitude through both types of dynamic membranes in high DOC natural water (HN). Reversible and ireversibe resistances were reduced by iron oxide to some extent in LN. Nevertheless the effect of iron oxide on fouling alleviation was much higher in HN than LN.

Removal of Humic Substances by Coagulation

1999 ◽  
Vol 40 (9) ◽  
pp. 47-54 ◽  
Author(s):  
C.R. O’Melia ◽  
W.C. Becker ◽  
K.-K. Au
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Complex Formation ◽  
Natural Organic Matter ◽  
Divalent Cations ◽  
Water Source ◽  
Quality Characteristic ◽  
Oxide Surfaces ◽  
Water Quality Characteristic ◽  
Coagulant Dosage

Measurements and modeling of the adsorption of natural organic matter (NOM) on oxide surfaces are presented and compared. Agreement is good and supports the view that the adsorption of NOM on oxides depends significantly on complex formation reactions between specific sites on oxide surfaces and functional groups on the NOM. Coagulant requirements can and often are set by the total organic carbon (TOC) concentration in a water source. Frequently there is a stoichiometric relationship between the required coagulant dosage and the TOC of the water to be treated. Other important factors include pH and the concentration of divalent cations. Ozone may benefit or retard coagulation, depending on coagulant type and the water quality characteristic that is dominant in setting the optimum coagulant dose.

Coupling effect of 17β-estradiol and natural organic matter on the performance of a PAC adsorption/membrane filtration hybrid system

Desalination ◽  
2009 ◽  
Vol 237 (1-3) ◽  
pp. 392-399 ◽  
Author(s):  
Kah-Young Song ◽  
Pyung-Kyu Park ◽  
Jae-Hyuk Kim ◽  
Chung-Hak Lee ◽  
Sangho Lee
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Hybrid System ◽  
Membrane Filtration ◽  
Coupling Effect ◽  
17Β Estradiol

scholarly journals NOM removal technologies – Norwegian experiences

2010 ◽  
Vol 3 (1) ◽  
pp. 1-9 ◽  
Author(s):  
H. Ødegaard ◽  
S. Østerhus ◽  
E. Melin ◽  
B. Eikebrokk
Keyword(s):  
Organic Matter ◽  
Activated Carbon ◽  
Humic Substances ◽  
Natural Organic Matter ◽  
Membrane Filtration ◽  
Granular Media ◽  
Physical Adsorption ◽  
Nanofiltration Membranes ◽  
Removal Technologies ◽  
Molecular Sieving

Abstract. The paper gives an overview of the methods for removal of natural organic matter (NOM) in water, particularly humic substances (HS), with focus on the Norwegian experiences. It is demonstrated that humic substances may be removed by a variety of methods, such as; molecular sieving through nanofiltration membranes, coagulation with subsequent floc separation (including granular media or membrane filtration), oxidation followed by biofiltration and sorption processes including chemisorption (ion exchange) and physical adsorption (activated carbon). All these processes are in use in Norway and the paper gives an overview of the operational experiences.

scholarly journals Modeling and characterization of natural organic matter and its relationship with the THMs formation

2016 ◽  
Vol 18 (4) ◽  
pp. 803-816 ◽  
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Formation Mechanism ◽  
Quality Characteristics ◽  
High Rate ◽  
Disinfection Process ◽  
By Products

<p>Natural organic matter (NOM) has been identified as the prominent precursor for disinfection by-products (DBPs) formation during chlorination. Various studies have shown that the characteristics of NOM influence the Trihalomethanes (THMs) formation mechanism. The present study represents NOM categorization in terms of total organic carbon (TOC), dissolved organic carbon (DOC), UV absorbance at 254 nm wavelengths (UV<sub>254</sub>) and specific ultraviolet absorbance (SUVA) to investigate the effects of NOM on THMs formation mechanism. The high rate of dependency was found for each representative of NOM with respect to water quality characteristics and operational condition of disinfection process. Values of SUVA and UV<sub>254</sub> is drastically reduced with respect from higher to a moderate chlorine dose which represent the chlorine contact is more predominant with hydrophobic fractions of NOM. The value of SUVA is decreasing with respect to temperature and reaction time, which reveled higher rate of utilization for hydrophobic fractions of NOM. Predictive modeling approach was carried out using multiple regression analysis with the combination of two surrogates at each stage of modeling with help of operational condition of disinfection process and water quality characteristics. The R<sup>2</sup> value of the model was found in the range of 0.927 to 0.937 from the developed model and a model could be recommended for prediction of THMs in drinking water.</p>

scholarly journals Progress, challenges, and opportunities in enhancing NOM flocculation using chemically modified chitosan: a review towards future development

2020 ◽  
Vol 6 (1) ◽  
pp. 45-61 ◽  
Author(s):  
Paripurnanda Loganathan ◽  
Michael Gradzielski ◽  
Heriberto Bustamante ◽  
Saravanamuthu Vigneswaran
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Natural Organic Matter ◽  
Bacterial Growth ◽  
Future Development ◽  
Raw Water ◽  
Modified Chitosan ◽  
Chemically Modified ◽  
Challenges And Opportunities ◽  
Flocculation Process

Natural organic matter (NOM) occurs ubiquitously in water bodies and this can greatly affect feed or raw water quality (taste, colour, odour, bacterial growth). Chemically modified chitosan can effectively remove NOM by the flocculation process.

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