Characterization of dissolved organic matter for prediction of trihalomethane formation potential in surface and sub-surface waters

Abstract

h i g h l i g h t s• Models of THMFP based on the character of precursor organics were developed.• UV 254 , HPSEC-UV and F-EEM provided data that could be used for THMFP prediction.• High removal of humic compounds by enhanced coagulation led to lower THM formation. Dissolved organic matter (DOM) in surface waters used for drinking purposes can vary markedly in character dependent on their sources within catchments. The character of DOM further influences the formation of disinfection by products when precursor DOM present in drinking water reacts with chlorine during disinfection. Here we report the development of models that describe the formation potential of trihalomethanes (THMFP) dependent on the character of DOM in waters from discrete catchments with specific land-use and soil textures. DOM was characterized based on UV absorbance at 254 nm, apparent molecular weight and relative abundances of protein-like and humic-like compounds. DOM character and Br concentration (up to 0.5 mg/L) were used as variables in models (R 2 > 0.93) of THMFP, which ranged from 19 to 649 g/L. Chloroform concentration (12 − 594 g/L) and relative abundance (27 − 99%) were first modeled (R 2 > 0.85) and from these, the abundances of bromodichloromethane and chlorodibromomethane estimated using power and exponential functions, respectively (R 2 > 0.98). From these, the abundance of bromoform is calculated. The proposed model may be used in risk assessment of catchment factors on formation of trihalomethanes in drinking water, in context of treatment efficiency for removal of organic matter. a r t i c l e i n f oCrown Copyright © 2016 Published by Elsevier B.V. All rights reserved.Abbreviations: AromDOC, aromatic-organic compounds concentration; Br, bromide ion concentration in raw waters; CHBr2Cl, chloro-dibromomethane formation potential; CHBr3, bromoform formation potential; CHCl2Br, bromo-dichloromethane formation potential; CHCl3, chloroform formation potential; DOC, dissolved organic carbon; DOM, dissolved organic matter; FA, percentage abundance of fulvic-like; HA, percentage abundance of humic-like; MW, molecular weight; NOM, natural organics matter; NonAromDOC, non-aromatic-organic compounds concentration; P(1), area under Peak 1; P(2-3), area under peaks 2&3; P(4-5), area under peaks 4&5; P(6-7), area under peaks 6&7; P(8-9), area under peaks 8&9; PI, percentage abundance of protein1-like; PII, percentage abundance of protein2-like; R 2 , coefficient of determination; SE, standard deviation; SMP, percentage abundance of soluble microbial protein-like; SUVA, Specific UV absorbance; THMFP, trihalomethane formation potential; UV254, UV absorbance at wavelength 254 nm.

Analysis of the Mixing Processes in a Shallow Subtropical Reservoir and Their Effects on Dissolved Organic Matter

“…The difference in SUVA levels between summer season and other seasons was statistically significant (p-value = 0.0053). This variation is due to increasing UV irradiation levels from spring to summer, leading to coloured aromatic DOM being degraded by sunlight [37]. Figure 5d indicates that the fDOM had a similar variation trend to that of the DOC concentration in reservoir water, i.e., an increase from July 2014 to April 2015 and a decline after April 2015.…”

A novel approach for application of white rot fungi in wastewater treatment under non-sterile conditions: immobilization of fungi on sorghum

“…They form strong complexes with heavy metals and can increase their transportation in waters [21]. Also, HS can react with chlorine during water treatment, and produce carcinogenic compounds such as trihalomethanes [22,23]. Moreover, a high residual HS concentration in treated water leads to a yellow or brown colour, which is undesirable [24].…”

Process Parameters Optimization of Gallic Acid Removal from Water by MIEX Resin Based on Response Surface Methodology

“…All of the experiments were performed in triplicate and the average values were calculated. The removal efficiency of GA by MIEX resin was then calculated by Equation (1).…”

“…Natural organic matter (NOM) widely exists in surface water and groundwater sources due to the breakdown of biomass [1]. Gallic acid (GA) is a typical fraction of NOM.…”