The evolution of organic character in a drought- and flood-impacted water source and the relationship with drinking water treatment

2014 ◽  
Vol 6 (3) ◽  
pp. 401-413 ◽  
Author(s):  
Rolando Fabris ◽  
Kalan Braun ◽  
James Y. Morran ◽  
Lionel Ho ◽  
Mary Drikas
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Activated Carbon ◽  
Membrane Filtration ◽  
Drinking Water Treatment ◽  
Apparent Molecular Weight ◽  
Climatic Conditions ◽  
Source Water ◽  
Uv Absorbance ◽  
Treatment Technology

A pilot-scale research investigation examining treatment technologies including coagulation, ion-exchange, activated carbon and membrane filtration and their impact on water quality coincided with a period of extensive variability in source water character. Distinct water quality periods as a result of extreme climatic conditions from drought to flood were observed and the natural organic matter (NOM) removal examined using a suite of organic characterisation techniques from simple ultraviolet (UV) absorbance to more advanced spectroscopic and chromatographic methods. The low specific UV absorbance (SUVA) and apparent molecular weight (AMW) distribution of the drought-impacted NOM was recalcitrant to coagulation with significant improvement in NOM removal resulting from the multi-step treatments. Among a number of discernible changes, floodwaters introduced high AMW, UV-absorbing NOM of terrestrial origin, which was shown to be more amenable to coagulation. Nevertheless the application of multi-step treatments resulted in further reduction in both the concentration and diversity of organic components. Filtration through granular activated carbon was observed to be the most variable treatment technology across the investigated period due to diminishing adsorption capacity. Conversely, the dual stage membrane filtration was shown to remove a broad range of organic matter, regardless of source water NOM concentration and character.

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.

scholarly journals Trihalomethane precursor reactivity changes in drinking water treatment unit processes during a storm event

2019 ◽  
Vol 19 (7) ◽  
pp. 2098-2106
Author(s):  
Chelsea W. Neil ◽  
Yingying Zhao ◽  
Amy Zhao ◽  
Jill Neal ◽  
Maria Meyer ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Plant Performance ◽  
Storm Event ◽  
Source Water ◽  
Treatment Unit ◽  
Source Water Quality

Abstract Source water quality can significantly impact the efficacy of water treatment unit processes and the formation of chlorinated and brominated trihalomethanes (THMs). Current water treatment plant performance models may not accurately capture how source water quality variations, such as organic matter variability, can impact treatment unit processes. To investigate these impacts, a field study was conducted wherein water samples were collected along the treatment train for 72 hours during a storm event. Systematic sampling and detailed analyses of water quality parameters, including non-purgeable organic carbon (NPOC), UV absorbance, and THM concentrations, as well as chlorine spiking experiments, reveal how the THM formation potential changes in response to treatment unit processes. Results show that the NPOC remaining after treatment has an increased reactivity towards forming THMs, and that brominated THMs form more readily than chlorinated counterparts in a competitive reaction. Thus both the reactivity and quantity of THM precursors must be considered to maintain compliance with drinking water standards, a finding that should be incorporated into the development of model-assisted treatment operation and optimization. Advanced granular activated carbon (GAC) treatment beyond conventional coagulation–flocculation–sedimentation processes may also be necessary to remove the surge loading of THM-formation precursors during a storm event.

Characterization of dissolved organic matter and disinfection characteristics of source water from the Pearl River

2007 ◽  
Vol 7 (2) ◽  
pp. 205-212
Author(s):  
Z.Y. Zhao ◽  
J.D. Gu ◽  
H.B. Li
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Chlorine Dioxide ◽  
Anthropogenic Activities ◽  
Apparent Molecular Weight ◽  
Water Disinfection ◽  
Size Exclusion ◽  
Pearl River ◽  
Source Water ◽  
Raw Water

Source water samples were collected from Guangzhou segment of Pearl River and filtered through Amicon® YC-05, YM-1, YM-3, YM-10, YM-30, YM-100 and ZM-500 membranes sequentially after pre-treatment. The apparent molecular weights of the 8 fractions were calibrated using high-performance size exclusion chromatograph (HPSEC) and they ranged from 0.36 to 182.6 kDa. These fractionated isolates and the raw water were disinfected by chlorine or chlorine dioxide to determine their disinfection characteristics. Results showed that apparent molecular weight of the main dissolved organic matter (DOM) in the RO isolate of water sample was less than 360 Da and this part of the DOM was mainly from anthropogenic activities and contamination of wastewater. RO fraction was the controlling factor for the raw water disinfection process according to the THMs concentrations detected. Disinfection by chlorine dioxide produced less THMs that by chlorine.

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.

Ozone: its effect on coagulation and filtration

2001 ◽  
Vol 1 (4) ◽  
pp. 81-88 ◽  
Author(s):  
W.C. Becker ◽  
C.R. O'Melia
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Metal Salt ◽  
Drinking Water Treatment ◽  
The United States ◽  
Quality Characteristic ◽  
Cationic Polymers ◽  
Water Quality Characteristic ◽  
Treatment Train ◽  
Coagulation And Filtration

The interest in ozone for drinking water treatment in the United States has increased dramatically in recent years due to new regulations and concern over Cryptosporidium. Ozone has many benefits, however, its expense is significant and its placement in the treatment train should be chosen with a sound understanding of its effect on other unit processes. The goal of this paper is to provide an overview of the effect of ozone on the coagulation and filtration processes. This is important given the enhanced coagulation requirements of the disinfection by-product rule and the filtered water quality goals of the Partnership for Safe Water. The effect of ozone on coagulation is shown to be dependent on the coagulant type and on the water quality characteristic that is setting the optimum coagulant dose. For waters with moderate to high dissolved organic carbon (DOC) levels, the coagulant dose is set by the DOC. Ozonation converts NOM into smaller, more oxygenated compounds, e.g. oxalic acid, that exert a greater metal salt coagulant demand than the parent compounds. In this case, higher dosages of alum or ferric chloride are needed. For low DOC waters, the coagulant dose is set by the particle and the adsorbed organic matter. Ozone may react with adsorbed DOC and alter the amount and conformation of adsorbed organic matter, which can lead to a decrease in the optimum coagulant dose. Finally, because cationic polymers react with particles and large organic matter (and not the smaller compounds formed after ozonation), the optimum polyelectrolyte coagulant dose after ozonation is reduced. Ozonation prior to filtration (intermediate ozonation) is shown to be beneficial for significantly reducing filtered water particle counts by as much as an order of magnitude.

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