Effects of water matrix and ozonation on natural organic matter fractionation and corresponding disinfection by-products formation

2014 ◽  
Vol 15 (1) ◽  
pp. 75-83 ◽  
Author(s):  
J. Agbaba ◽  
J. Molnar ◽  
A. Tubić ◽  
M. Watson ◽  
S. Maletić ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Oxidation Treatment ◽  
Trihalomethane Formation Potential ◽  
Water Matrix ◽  
Organic Matter Fractionation ◽  
Influence Of Water ◽  
The Individual ◽  
By Products

In this study the influence of water matrix and oxidation treatment by ozone on natural organic matter (NOM) fractionation and corresponding disinfection by-products formation was investigated. Three water types were selected, based on their different NOM contents (5.16–9.85 mg/L dissolved organic carbon (DOC)) and structures (42–79% proportion of hydrophobic NOM fraction). It was determined that increasing the ozone dose (0.2–0.8 mg O3/mg DOC) generally led to reductions in DOC (2–26%) and trihalomethane formation potential values (4–58%). Results of NOM fractionation showed that the reactivity of all the individual NOM fractions towards trihalomethane formation decreased after ozone oxidation (0.8 mg O3/mg DOC) by 47–69%, relative to the raw waters.

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>

Removal of natural organic matter and trihalomethane formation potential in a full-scale drinking water treatment plant

2013 ◽  
Vol 13 (4) ◽  
pp. 1099-1108 ◽  
Author(s):  
Ekaterina Vasyukova ◽  
René Proft ◽  
Johanna Jousten ◽  
Irene Slavik ◽  
Wolfgang Uhl
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Full Scale ◽  
Formation Potential ◽  
Trihalomethane Formation Potential

A multidisciplinary approach was applied in this work to characterise natural organic matter and evaluate the performance of a full-scale waterworks treating organic-rich surface water. It was shown that the combination of the treatment processes considered efficiently removed the dissolved organic matter, including its specific fractions. Most of the dissolved organic carbon and nitrogen (DOC and DON), biodegradable DOC and DON, as well as assimilable organic carbon were removed by coagulation/sedimentation. However, the coagulation process was not likely to be optimised for the removal of all molecular weight compounds. The breakdown of high molecular weight compounds into others of low molecular weight, as well as the production of biodegradable organic matter during ozonation, proved to enhance their removal efficiency by subsequent biological activated carbon filtration. The specific trihalomethane formation potential decreased during treatment, indicating a decrease in reactivity of DOC with chlorine across the treatment train. Fractionation experiments demonstrated that high and medium molecular weight organics were likely to be the main precursors for the formation of trihalomethanes. However, other disinfection by-products (such as haloacetic acids) should also be controlled, as the chlorine demand pattern did not necessarily follow that of trihalomethane formation.

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.

The effects of ultraviolet/H2O2 advanced oxidation on the content and characteristics of groundwater natural organic matter

2014 ◽  
Vol 15 (1) ◽  
pp. 34-41 ◽  
Author(s):  
J. Molnar ◽  
J. Agbaba ◽  
A. Tubić ◽  
M. Watson ◽  
M. Kragulj ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Advanced Oxidation ◽  
Total Content ◽  
Process Conditions ◽  
Water Type ◽  
H2o2 Treatment ◽  
Trihalomethane Formation Potential ◽  
Aromatic Character ◽  
A Minor

This work investigates the effects of ultraviolet (UV)/H2O2 advanced oxidation on the content and characteristics of natural organic matter (NOM) originating from two different groundwaters (3.03–9.69 mg/L total organic carbon (TOC), 2.71–4.31 Lmg−1m−1 specific ultraviolet absorbance (SUVA)). Application of UV irradiation resulted in a minor reduction in the total content of NOM. Using UV/H2O2 advanced oxidation led to a significant reduction of the aromatic character of NOM (SUVA was reduced by up to 80%) and an increase in the hydrophilic character of the residual NOM, with the optimal UV/H2O2 treatment conditions depending on the water type. In addition, fluctuations in trihalomethane formation potential (THMFP) were observed depending on the UV/H2O2 process conditions, with a maximal reduction of about 40% achieved for both waters.

Advanced oxidation processes: flowsheet options for bulk natural organic matter removal

2004 ◽  
Vol 4 (4) ◽  
pp. 113-119 ◽  
Author(s):  
C.A. Murray ◽  
S.A. Parsons
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Natural Organic Matter ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Fenton’S Reagent ◽  
Fenton's Reagent ◽  
Oxidation Processes

Advanced oxidation processes have been reported to have the potential to remove natural organic matter from source waters. Of these Fenton's reagent, photo-Fenton's reagent and titanium dioxide photocatalysis are the three most promising processes. Compared to conventional coagulation/flocculation processes they have higher removal efficiencies in terms of both dissolved organic carbon and UV254 absorbance. Under optimum reaction conditions all three remove over 80% dissolved organic carbon and 0% UV254 absorbance. In addition the enhanced removal of natural organic matter leads to a corresponding reduction in the formation of disinfection by-products following chlorination of the treated water. Advanced oxidation processes give enhanced removal of organic species ranging from low to high molecular weight while coagulation/flocculation is inefficient at removing low molecular weight species. One additional benefit is all three processes produce less residuals compared to conventional coagulation, which is advantageous as the disposal of such residuals normally contributes a large proportion of the costs at water treatment works.

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 Effects of ozonation and temperature on biodegradation of natural organic matter in biological granular activated carbon filters

2010 ◽  
Vol 3 (1) ◽  
pp. 107-132 ◽  
Author(s):  
L. T. J. van der Aa ◽  
L. C. Rietveld ◽  
J. C. van Dijk
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Activated Carbon ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Granular Activated Carbon ◽  
Carbon Dioxide Production ◽  
Oxygen Removal ◽  
Theoretical Maximum ◽  
Increasing Temperature

Abstract. Four pilot (biological) granular activated carbon ((B)GAC) filters were operated to quantify the effects of ozonation and water temperature on the biodegradation of natural organic matter (NOM) in (B)GAC filters. Removal of dissolved organic carbon (DOC), assimilable organic carbon (AOC) and oxygen and the production of carbon dioxide were taken as indicators for NOM biodegradation. Ozonation stimulated DOC and AOC removal in the BGAC filters, but had no significant effect on oxygen removal and carbon dioxide production. The temperature had no significant effect on DOC and AOC removal, while oxygen removal and carbon dioxide production increased with increasing temperature. Multivariate linear regression was used to quantify these relations. In summer the ratio between oxygen consumption and DOC removal exceeded the theoretical maximum of 2.5 g O2·g C−1 and the ratio between carbon dioxide production and DOC removal exceeded the theoretical maximum of 3.7 g CO2·g C−1. Bioregeneration of large NOM molecules could explain this excesses and the non-correlation between DOC and AOC removal and oxygen removal and carbon dioxide production. However bioregeneration of large NOM molecules was considered not likely to happen, due to sequestration.

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