scholarly journals Control of disinfection by-products and biodegradable organic matter through biological treatment

2005 ◽  
Vol 5 ◽  
pp. 1-15 ◽  
Author(s):  
H. M. Shukairy ◽  
R. J. Miltner ◽  
R. S. Summers
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
River Water ◽  
Biological Treatment ◽  
Ohio River ◽  
Formation Potential ◽  
Ozone Dose ◽  
Chlorine Demand ◽  
By Products ◽  
Biodegradable Organic Matter

The optimal use of ozonation as a pretreatment process prior to biological treatment of Ohio River water was investigated at both the bench (batch) and pilot-plant (continuous flow) scale. The study focused on disinfection by-products (DBPs) and DBP precursor compounds and on the production of biologically stable water. Biotreatment was achieved using a bench-scale fixed-film reactor with sand acclimated to the raw Ohio River water. Ozonation was found to create a number of aldehydes, in particular formaldehyde, methyl glyoxal, glyoxal and acetaldehyde. With the exception of formaldehyde, a plateau in the aldehyde yield occurred at an ozone to total organic carbon (03/TOC) ratio of 0,7 mg/mg, while formaldehyde increased with increasing ozone dose. After biotreatment, the concentration of aldehydes were below 1 µg/1. Increasing ozone doses were also found to increase the assimilable organic carbon (AOC), by both NOX and P17 procedures, and the biodegradable dissolved organic carton (BDOC). The AOC values showed a maximum at about an 03/TOC ratio of 2 mg/mg, white the BDOC continued to increase with the highest ozone dose : an 03/TOC ratio of 2,8 mg/mg. Both ozonation and biotreatment were fond to decrease the chlorine demand by up to 75 % for ozonation and 55 % for biotreatment. Similar trends were found for the impact of ozonation and biotreatment on the precursor compounds for total organic halogen (TOX), total trihalomethanes (TTHMs) and total haloacetic acids (THAAs), as measured by the formation potential (FP) test : 12 mg/l chlorine, 7 days, 25 °C, 6.5-7.2 pH. An ozone dose of 0.4 03/DOC (mg/mg) decreased the TOXFP, TTHMFP and THAAFP by 28 %, 23 % and 33 %, respectively. Further increases in ozone only marginally increased the amount of the TOXFP and TTHMFP removed, white a maximum removal of 53 % of the THAAFP occurred at 03/DOC ratio of 0.87 mg/mg. Biotreatment of the nonozonated samples yielded 39 %, 38 % and 73 % removal of the TOXFP, TTHMFP and THAAFP, respectively. Biotreatment of the ozonated sample yielded a 30 to 50 % reduction in TOXFP and TTHMFP, while a constant level of 30 to 40 µg/l of THAAFP was achieved. Chloropicrin formation potential increased with ozone dose, but subsequent biotreatment reduced it to below 0.2 µg/l. Ozonation was Pound to oxidize chorine demand and the precursors for TOX, THM and HAAs. However, it created chloropicrin precursors, aldehydes and other biodegradable organic matter. Biotreatment was found to further reduce the chlorine demand, the precursors for TOX, THMs and HAAs and reduce the ozone created disinfection by-products.

Evaluation of odour removal by pilot-scale biological treatment process trains during spring runoff in an ice-covered river

1995 ◽  
Vol 31 (11) ◽  
pp. 195-201 ◽  
Author(s):  
S. E. Hrudey ◽  
P. M. Huck ◽  
M. J. Mitton ◽  
S. L. Kenefick
Keyword(s):  
Organic Carbon ◽  
Biological Treatment ◽  
Pilot Scale ◽  
Raw Water ◽  
Formation Potential ◽  
Trihalomethane Formation Potential ◽  
The North ◽  
Spring Runoff ◽  
Odour Removal ◽  
By Products

Biological water treatment has been shown to effectively remove biodegradable organic matter, chlorinated by-products and ozonation by-products from drinking water during a large pilot-scale study for the American Water Works Association Research Foundation using the North Saskatchewan River, at Edmonton. In addition to studying total organic carbon, assimilable organic carbon, chlorine demand, haloacetic acid formation potential, trihalomethane formation potential, adsorbable organic halide formation potential, chloral hydrate and aldehydes, this study used a flavour profile panel to follow the removal of odour through different process trains involving biological treatment during the annual spring runoff which has historically caused odour incidents in the water supply. Over the 5-week period of the study, the raw water was found to develop from a very mild grassy odour to a strong odour, variously characterized as septic, manure, musty, earthy and hay-like. The odour persisted and changed character to varying degrees through the various process trains under study. The results verified the futility of relying on a strictly oxidative treatment like ozone for odour removal as well as showing that biological treatment using granular activated carbon could produce an essentially odour-free effluent during a transient raw-water odour event.

Effets de l'ozonation et de la filtration biologique sur la demande en chlore et sur les précurseurs de trihalométhanes et des composés organo-halogénés totaux

1995 ◽  
Vol 22 (5) ◽  
pp. 945-954
Author(s):  
Hélène Baribeau ◽  
Michèle Prévost ◽  
Raymond Desjardins ◽  
Pierre Lafrance ◽  
Bernard Legube
Keyword(s):  
Activated Carbon ◽  
Organic Carbon ◽  
Biological Treatment ◽  
Residual Chlorine ◽  
Short Term ◽  
Biological Activated Carbon ◽  
Organic Halides ◽  
Chlorine Demand ◽  
Carbon Filtration ◽  
By Products

The effects of biological treatment (ozonation followed by biological activated carbon filtration (BAC)) on chlorine demand and on formation of trihalomethanes (THM) and total organic halides compounds (TOH) were studied at the Sainte-Rose water treatment facility, Laval. The plant influent is a surface water with a dissolved organic carbon of 6–7 mg/L. Results showed that ozonation marginally reduced (0–6%) short term chlorine demand but that BAC filtration reduced it by 40–55%. Ozonation versus BAC filtration was found to effect THM and TOH formation differently from the removal of the chlorine demand. THM (4-h contact with chlorine) and TOH formations were reduced by 48–60% and 39%, respectively, via ozonation. With BAC filtration, THM and TOH formations were reduced by 20–34% and 16%, respectively, with respect to the ozonated influent. For all essays, an initial significant decrease in residual chlorine was followed by an increase in TOH and subsequently in THM. The initial chlorine doses used for measuring the chlorine demand were found to have an effect on the final results. An increase in the initial chlorine dose resulted in a higher chlorine demand as well as in higher THM and TOH formations. The effect was found to be more profound at chlorine doses less than 3 mg Cl2/mg total organic carbon. Key words: chlorine demand, chlorination by-products, trihalomethane, total organic halides, ozonation, filtration, biological activated carbon.

Impacts of the Reduction of Nutrient Levels on Bacterial Water Quality in Distribution Systems

1999 ◽  
Vol 65 (11) ◽  
pp. 4957-4966 ◽  
Author(s):  
Christian J. Volk ◽  
Mark W. LeChevallier
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Organic Carbon ◽  
Biological Treatment ◽  
Distribution Systems ◽  
Model Systems ◽  
Biological Filtration ◽  
Nutrient Levels ◽  
Bacterial Concentrations ◽  
Biodegradable Organic Matter

ABSTRACT This study evaluated the impacts of reducing nutrient levels on bacterial water quality in drinking water. Two American Water System facilities (sites NJ102a and IN610) with histories of coliform problems were involved, and each water utility received two pilot distribution systems (annular reactors). One reactor simulated the conventional treatment conditions (control), while the other reactor was used to assess the effect of biological filtration and subsequent reduced biodegradable organic matter levels on suspended (water column) and biofilm bacterial concentrations in the distribution systems. Biodegradable organic matter levels were reduced approximately by half after biological treatment. For site NJ102a, the geometric mean of the assimilable organic carbon concentrations was 217 μg/liter in the plant effluent and 91 μg/liter after biological filtration. For both sites, plant effluent biodegradable dissolved organic carbon levels averaged 0.45 mg/liter, versus 0.19 to 0.22 mg/liter following biological treatment. Biological treatment improved the stability of free chlorine residuals, while it had little effect on chloramine consumption patterns. High bacterial levels from the biological filters resulted in higher bacterial concentrations entering the test reactors than entering the control reactors. On average, biofilms in the model systems were reduced by 1 log unit (from 1.4 × 105 to 1.4 × 104 CFU/cm2) and 0.5-log unit (from 2.7 × 105 to 7.8 × 104CFU/cm2) by biological treatment at sites NJ102a and IN610, respectively. Interestingly, it required several months of biological treatment before there was an observable impact on bacterial water quality in the system, suggesting that the effect of the treatment change was influenced by other factors (i.e., pipe conditions or disinfection, etc.).

Removal of trihalomethanes from high organic matter water sources using aeration: a feasibility study

2020 ◽  
Vol 55 (2) ◽  
pp. 184-197
Author(s):  
Saeideh Mirzaei ◽  
Beata Gorczyca
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Feasibility Study ◽  
Distribution Systems ◽  
Water Age ◽  
Treated Water ◽  
Canadian Guideline ◽  
Viable Solution ◽  
By Products

Abstract In this study, diffused aeration was applied to remove trihalomethane (THM) compounds from chlorinated, treated water containing high dissolved organic carbon (DOC) of 6.8 ± 1.2 mg/L. Increasing air-to-water volumetric ratio (rA/W) from 16 to 39 enhanced total THM (TTHM) removal from 60 to 70% at 20 °C and from 30 to 50% at 4 °C. Although bromodichloromethane has lower Henry's law constant than chloroform (CF), it was removed by a higher degree than CF in some aeration trials. Albeit obtaining high removals in aeration, TTHM reformed, and their concentration surpassed the Canadian guideline of 100 ppb in about 24 hours at 20 °C and 40 hours at 10 °C in all attempted air-to-water ratios. The water age in the system investigated in this study varied from 48 hours in midpoint chlorine boosting stations to 336 hours in the nearest endpoint. This study showed that THM removal by aeration is not a viable solution to control the concentration of these disinfection by-products in high-DOC treated water and in distribution systems where water age exceeds 24 hours; unless, it is going to be installed at the distribution endpoints.

scholarly journals Removal of Trihalomethane Precursors by Nanofiltration in Low-SUVA Drinking Water

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1370 ◽  
Author(s):  
Yael Dubowski ◽  
Roni Greenberg-Eitan ◽  
Menachem Rebhun
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Natural Organic Matter ◽  
Low Molecular Weight ◽  
Water Recovery ◽  
Formation Potential ◽  
Pressure Water ◽  
Membrane Type ◽  
Hydrophilic Organic Matter ◽  
By Products

Trihalomethanes (THMs) are prevalent disinfection by-products. High THM formation is usually associated with natural organic matter with high molecular weight and aromatic characteristics, which is efficiently removed by nanofiltration (NF). In the Sea of Galilee and the Israeli National Water Carrier (NWC), water shows high THM formation potential, although it mainly contains low molecular weight and hydrophilic organic matter with low aromaticity. In the present study, NF removal abilities were tested on treated NWC water using three different spiral wound membranes (NF90, NF270, and DL). Rejections and fluxes were tested as a function of pressure, water recovery, and membrane type. Feed and permeate dissolved organic carbon (DOC), UVA254, total THM formation (THMF), and total THM formation potential (THMFP), as well as alkalinity, conductivity, hardness, Ca2+, Mg2+, and Cl− were measured to evaluate rejection and THM formation reduction. The results demonstrated that NF can efficiently remove natural organic matter (NOM) and reduce THM formation, even in this challenging type of water. At low water recovery, membranes showed average rejection of about 70–85% for THMFP and THM. Upon elevating recovery, average THM and THMFP rejection decreased to 55–70%, with THM content still well below regulation limits. Of the membranes tested, the higher permeability of NF270 appears to make it economically favorable for the applications tested in this work.

Molecular weight distribution of organic matter by ozonation and biofiltration

2012 ◽  
Vol 66 (12) ◽  
pp. 2604-2612 ◽  
Author(s):  
Yen-Hui Lin
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Organic Carbon ◽  
Organic Molecule ◽  
Drinking Water Treatment ◽  
Gel Chromatography ◽  
Group 4 ◽  
Ozone Dose ◽  
Experimental Approaches ◽  
Group 2

Molecular weight (MW) distribution of organic matter by ozonation and biofiltration was evaluated using gel chromatography. The MW distribution of organic matter by Sephadex G-25 was observed from groups 2 (MW = 1,029–7,031 g/mol) and 3 (MW = 303–1,029 g/mol) shifted to groups 2, 3 and 4 (MW < 303 g/mol) under ozone doses of 0.1 and 0.4 mg O3/mg total organic carbon (TOC). The shift in MW increases as ozone dosage increases. Biofiltration effectively degraded the organic molecule of group 2; however, the biofiltration only slightly degraded the organic molecule of group 4. Increased ozone dose destroyed functional groups C═C in phenolic and C–O in alcoholic compounds and increased UV-insensitive biodegradable organic carbon for subsequent biofiltration. Biofiltration effectively degraded organic compounds of alcohols and alkenes at an ozone dose of 0.1 mg O3/mg TOC. Experimental approaches in this study can be applied to evaluate and diagnose the function of a full-scale process combining ozonation and biofiltration in drinking water treatment plants.

Variations of DBPs precursors according to location within the distribution system

2009 ◽  
Vol 9 (4) ◽  
pp. 413-421
Author(s):  
C. Beaulieu ◽  
M. J. Rodriguez ◽  
J.-B. Sérodes
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Spatial Behavior ◽  
Haloacetic Acids ◽  
Formation Potential ◽  
The Impact ◽  
By Products

Little information is available on the evolution of remaining organic matter (ROM) in a water distribution system (WDS) and its impact on the generation of disinfection by-products (DBPs). This research involves the characterization, through sample fractionation processes and experimental chlorination tests, of the reactivity of DBP precursors occurring within a WDS. The study is based on samples collected in various locations of a WDS during a complete year. For each sample, six fractions were generated to determine their potential for formation of trihalomethanes (THMs) and haloacetic acids (HAAs). Fractionation processes on ROM demonstrated that the spatial behavior of precursors for THMs differs from that for precursors of HAAs. In addition, experimental chlorination tests showed that the reactivity of the investigated fractions, in terms of DBP formation potential (DBPfp), was different from each other according to location in the WDS. DBPfp for the studied fractions changed drastically during water treatment. However, changes of DBPfp for fractions were relatively low between the beginning and the extremity of the distribution system. Since the results of this research confirm that the ability to produce DBPs is related to the nature of the fractions, they could be useful to evaluate the impact of re-chlorination on DBP formation in a WDS.

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>

Dissolved Organic Carbon Removal from a Prairie Water Supply Using Ozonation and Biological Activated Carbon

1999 ◽  
Vol 34 (4) ◽  
pp. 615-632 ◽  
Author(s):  
Joanne Sketchell ◽  
Hans G. Peterson ◽  
Nick Christofi
Keyword(s):  
Activated Carbon ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Source ◽  
Drinking Water Source ◽  
Biological Activated Carbon ◽  
Chlorine Demand ◽  
Biodegradable Dissolved Organic Carbon ◽  
Carbon Filtration ◽  
By Products

Abstract Large quantities of dissolved organic carbon in prairie surface water reservoirs make sustainable treatment quite challenging. Organic material is a precursor for the formation of disinfection by-products. Here, ozonation and biological activated carbon filtration were used as methods for removing dissolved organic carbon from the water of a small prairie reservoir used as a drinking water source. Biofiltration alone yielded significant reductions in dissolved organic carbon, colour, total trihalomethanes and chlorine demand. When ozonation preceded biofiltration, the increased proportion of biodegradable dissolved organic carbon allowed for significantly greater (p&lt;0.05

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