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.

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.

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.

Membrane filtration of wastewater effluents for reuse: effluent organic matter rejection and fouling

2001 ◽  
Vol 43 (10) ◽  
pp. 225-232 ◽  
Author(s):  
C. Jarusutthirak ◽  
G. Amy
Keyword(s):  
Organic Matter ◽  
Membrane Filtration ◽  
Treated Wastewater ◽  
High Concentration ◽  
Effluent Organic Matter ◽  
Dead End ◽  
Flux Decline ◽  
Uf Membranes ◽  
Stirred Cell ◽  
Filtration Unit

The reuse of treated wastewater to augment natural drinking water supplies is receiving serious consideration. Treatment of secondary and tertiary effluent by membrane filtration was investigated by assessing nanofiltration (NF) membrane and ultrafiltration (UF) membranes in bench-scale experiments. It was found that secondary and tertiary effluent contained high concentration of effluent organic matter (EfOM), contributing EfOM-related fouling. Flux decline and EfOM rejection tests were evaluated, using a dead-end stirred cell filtration unit. Surface charge and molecular weight cut-off (MWCO) of membranes were significant factors in membrane performance including permeability and EfOM-rejection.

Suspended particles in the drinking water of two distribution systems

2001 ◽  
Vol 1 (4) ◽  
pp. 237-245 ◽  
Author(s):  
V. Gauthier ◽  
B. Barbeau ◽  
R. Millette ◽  
J.-C. Block ◽  
M. Prévost
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Organic Matter ◽  
Distribution System ◽  
Distribution Systems ◽  
Suspended Solids ◽  
Suspended Particles ◽  
Raw Water ◽  
Remote Locations ◽  
Dissolved Matter

The concentrations of suspended particles were measured in the drinking water of two distribution systems, and the nature of these particles documented. The concentrations of particulate matter were invariably found to be small (maximum 350 μg/L). They are globally in the very low range in comparison with dissolved matter concentrations, which are measured in several hundreds of mg/L. Except during special water quality events, such as turnover of the raw water resource, results show that organic matter represents the most important fraction of suspended solids (from 40 to 76%) in treated and distributed water. Examination of the nature of the particles made it possible to develop several hypotheses about the type of particles penetrating Montreal's distribution system during the turnover period (algae skeleton, clays). These particles were found to have been transported throughout the distribution systems quite easily, and this could result in the accumulation of deposits if their surface charge were ever even slightly destabilised, or if the particles were to penetrate the laminar flow areas that are fairly typical of remote locations in distribution systems.

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.

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.

scholarly journals Biodegradation Behavior of Ozonated Natural Organic Matter in Sand Filters

2005 ◽  
Vol 9 (1) ◽  
pp. 3-16 ◽  
Author(s):  
J. Z. Wang ◽  
R. S. Summers
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Glyoxylic Acid ◽  
Complex Mixture ◽  
Drinking Water Treatment ◽  
Sand Filters ◽  
Substrate Removal ◽  
Exchange Resins

Natural organic matter (NOM) in drinking water is a complex mixture of organic compounds. Some of the compounds are not biodegradable, while others are quickly biodegradable and a third group is more resistant to biodegradation. To have a better understanding of the biofiltration process in drinking water treatment, it is important to identify the elements of the quickly and slowly biodegradable NOM and to characterize the biodegradation rate of each element. In this study, an ozonated NOM solution was used as the substrate. The NOM was isolated from a groundwater in Germany using ion-exchange resins. The ozone dose was 0.35 mg O3/mg DOC (dissolved organic carbon). Previously bioacclimated sand was used as filter media and biomass source and was homogeneously distributed in the filter prior to each run. The substrate removal was evaluated by DOC, biodegradable DOC (BDOC), assimilable organic carbon (AOC), aldehyde and ketoacid analyses. When expressed in terms of the empty bed contact time (EBCT), the results showed that filter velocity in the range of 1.5 to 15 m/hr had no impact on substrate removal. This implies that substrate utilization, not external mass transfer, is the rate limiting step for substrate removal in drinking water biofilters. In this study, compounds or NOM fractions are termed quickly biodegradable if they are removed in the first three minutes of EBCT. 15% of the DOC was removed by the biofilter within three minutes of EBCT and was termed the quickly biodegradable fraction. The BDOC fraction of the ozonated solution was determined to be 40 to 45% of the DOC. In terms of BDOC, about one third of the total BDOC was quickly biodegradable. The AOC results show that about 90% of the total AOC was utilized by Spirillum sp. NOX (AOC-NOX). Most of the AOC was quickly biodegradable and was removed within one minute of EBCT. For aldehydes, glyoxal and methyl glyoxal were removed to below the detection limit after two minutes of EBCT. However, only 60% of formaldehyde removal was achieved in the first two minutes of EBCT, and no additional removal was achieved with increasing EBCT. Additionally, no significant removal of acetaldehyde was observed. The results of ketoacids show that their utilization rates were very high. More than 90% of glyoxylic acid and pyruvic acid were removed within one minute of EBCT.

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 Mixing State of Submicrometer Sea Spray Particles Enriched by Insoluble Species in Bubble-Bursting Experiments

2014 ◽  
Vol 31 (1) ◽  
pp. 93-104 ◽  
Author(s):  
Ji Yeon Park ◽  
Sungil Lim ◽  
Kihong Park
Keyword(s):  
Organic Matter ◽  
Membrane Filtration ◽  
Volume Fraction ◽  
Silica Particles ◽  
Artificial Seawater ◽  
Sea Spray ◽  
Natural Seawater ◽  
Mixing State ◽  
High Concentration ◽  
Dissolved Salts

Abstract Measurements of size distribution, hygroscopicity, and volatility of submicrometer sea spray particles produced by the bubble busting of artificial and natural seawater were conducted to determine their mixing state and volume fractions of hygroscopic and nonhygroscopic species or volatile and nonvolatile species. The particles sprayed from artificial seawater having insoluble silica particles were found to be an external mixture of two groups of particles having hygroscopic growth factors (HGFs) of 1.33 (an internal mixture of nonhygroscopic silica particles and hygroscopic salt species) and 1.68 (a similar mixture having more salt species) when the mass ratio of insoluble particles to dissolved salts was higher than 2. For sea spray particles from natural seawater, the external mixing was not significantly observed because of a high concentration of dissolved salts. The HGFs of sea spray particles (80–140 nm) from natural seawater were in the range of 1.70–1.76, which were lower than from pure artificial seawater (1.87), and the HGFs had no change before and after membrane filtration of seawater, suggesting that the sea spray particles from natural seawater contained a significant amount of nonhygroscopic dissolved organic matter in addition to hygroscopic salt species. The volume fraction of the nonhygroscopic species ranged from 20% to 29%, and the highest value was observed for seawater samples from the site where strong biological activity occurred, suggesting that biological materials played an important role in the formation of nonhygroscopic organic matter. Volatility measurements also identified the existence of volatile organic species in single particles from natural seawater, with the volume fraction of volatile species evaporated at 100°C being 4%–5%.

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