Characterization of Natural Organic Matter in Advanced Water Treatment Processes for DBPs Control
نویسندگان
چکیده
A demonstration plant consisted of granular activated carbon (GAC) and ozone/GAC process was operated using filtered water of a conventional water treatment plant as influent to study feasibility of introducing advanced water treatment. Natural organic matter (NOM) from process waters at the demonstration plant was isolated into hydrophobic and hydrophilic fractions by physicochemical fractionation methods to investigate its characteristics. In the case of hydrophobic fraction (i.e. humic substances; HS), the structural and chemical characteristics were investigated using various spectroscopic methods. Through ozonation and carbon adsorption, the hydrophobic fraction and hydrophilic fraction gradually decreased from 22.0 % to 14.7 % and from 38.6 % to 20.8 % based on the content in raw water, respectively. Formation of trihalomethanes (THMs) was highly influenced by hydrophobic fraction, whereas haloacetic acids formation potential (HAAFP) depended more on the hydrophilic fraction. Concentration of phenolic group in the HS gradually decreased from 60.5 % to 15.8 % through the water treatment and a higher yield of THMs resulted from chlorination of NOM with a higher phenolic content. The structural changes of HS identified from FT-IR and H-NMR were consistent with the results from the isolation of functional groups in the HS fractionated using A-21 resin. Decreases of ratio of UV absorbance at 253nm and 203nm, respectively (A253/A203) and DBPFPs/DOC showed consistent trends, therefore, the A253/A203 ratio may be a good indicator of tendency for the DBPs formation.
منابع مشابه
مطالعه خصوصیات اجزاء مواد آلی طبیعی در منابع سطحی آب تهران
Background and Objectives: Natural organic matters (NOMs) are abundant in natural water resources and in many ways may affect the unit processes in water treatment. Although NOMs are considered harmless but they have been recognized as disinfection by-products (DBPs) precursors during the chlorination process. Formation of DBPs highly depends on the composition and concentration of NOMs. The ob...
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Background and Aim: Natural organic matter (NOMs), measured on the basis of organic carbon, produces disinfection by-products precursors (DBPs) during the chlorination process. Some DBPs are carcinogenic. NOMs are not completely removed by conventional water treatment. As a result, in addition to forming DBPs, they support bacterial regrowth in the water distribution systems and cause unpleasan...
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