Characterization of natural organic matter and disinfection byproducts formation potential in pilot-scale coagulation-ultrafiltration membrane combined process in winter

Abstract

Abstract：A pilot-scale ultrafiltration membrane plant was set up for treating Luanhe River water with flocculating and precipitation process of waterworks. The aim is to investigate the variation and characteristics of natural organic matter and disinfection byproducts formation potential in the whole process in winter. The results show that dissolved organic matter (DOM), UV 254 , trihalomethanes formation potential (THMsFP) and haloacetic acids formation potential (HAAsFP) of Luanhe River water were mainly distributed in the range of molecular weight (MW) <1 kDa, so were the membrane feed water and treated water by membrane. Specific UV absorbance, specific THMsFP and specific HAAsFP have the maximal value in the MW fraction of 1-3 kDa, except that specific UV absorbance of membrane feed water is in the range of 3-10 kDa; DOM of membrane backwash water is mainly distributed in the range of MW>30 kDa and MW<1 kDa. It is the DOM in water backwashing in up way that made significant contribution to the higher dissolved organic carbon content in membrane backwash water. However, UV 254 , THMsFP and HAAsFP were mainly distributed in the range of MW<1 kDa. The highest concentrations of specific THMsFP and specific HAAsFP appeared in the MW fraction of 3-10 kDa. CHCl 3 was the major THMs species during MBW chlorination and occupied more than 60% of the total THMsFP. Dichloroacetic acid and trichloroacetic acid were the main components in HAAsFP. The concentration of THMsFP and HAAsFP in MBW was influenced by operation period.The polluted water sources and enhancement of water quality requirements lead to the fact that the traditional treatment process cannot meet the stringent drinking water standards. The ultrafiltration (UF) membrane is regarded as a substitute of traditional drinking water treatment process for its efficient retention of particles and viruses in water [1] . The research on the distribution and characterization of natural organic matter (NOM) and disinfection byproducts formation potential (DBPFP) arouses special attention [2,3] . Variation in the amount and nature of NOM, especially with respect to changes in the aromatic carbon content, has become significant factors for designing water treatment strategies [4] . NOM in water not only produces chromaticity, turbidity and eutrophication, but also produces disinfection byproducts(DBPs), and many of them have been proved to be carcinogenic [5] . At present, most researches regarding the occurrence of chlorinated DBPs in drinking water are on trihalomethanes (THMs) formation and evolution [6] , and a few are on haloacetic acids (HAAs). In order to better remove NOM in the UF process, membrane filtration can be combined with other unit processes, such as coagulation, precipitation and adsorption [7] . Research on the characteristics of NOM in the combined process and the role in forming DBPFP may shed light on more effective solutions to controlling NOM and decreasing DBPs in the treatment process during the period of low temperature and low turbid...

Identification of disinfection by-product precursors by natural organic matter fractionation: a review

“…In contradiction to the above ndings, increasing formation potential with increasing molecular weight have also been reported and some studies show no correlation at all between the formation potential and molecular weight. Con icting conclusions exist as well for both speci c di-halogenated and tri-halogenated acetic acid formation potentials and emerging disinfection by-products (An et al, 2017;Avsar et al, 2015;Chang et al, 2001;Chiang et al, 2002;Gang et al, 2003;Ge et al, 2020;Goslan et al, 2004;Hu et al, 2015;Hua and Reckhow, 2007b;Hua et al, 2015;Hua et al, 2020;Karapinar et al, 2014;Kitis et al, 2002;Lin et al, 2014;Liu et al, 2011;Özdemr, 2014;Pi et al, 2021;Pramanik et al, 2015;Wei et al, 2008a;Wei et al, 2008b;Xu et al, 2007;Xu et al, 2011;Zhang et al, 2021;Zhang et al, 2020b;Zhang et al, 2010;Zhang et al, 2018;Zhao et al, 2006;Zhao et al, 2009).…”

Identification of disinfection by-product precursors by natural organic matter fractionation: a review

“…In contradiction to the above findings, increasing formation potential with increasing molecular weight have also been reported and some studies show no correlation at all between the formation potential and molecular weight. Conflicting conclusions exist as well for both specific di-halogenated and tri-halogenated acetic acid formation potentials and emerging disinfection by-products (An et al, 2017;Avsar et al, 2015;Chang et al, 2001;Chiang et al, 2002;Gang et al, 2003;Ge et al, 2020;Goslan et al, 2004;Hu et al, 2015;Hua and Reckhow, 2007b;Hua et al, 2015;Hua et al, 2020;Karapinar et al, 2014;Kitis et al, 2002;Lin et al, 2014;Liu et al, 2011;Özdemr, 2014;Pi et al, 2021;Pramanik et al, 2015;Wei et al, 2008a;Wei et al, 2008b;Xu et al, 2007;Xu et al, 2011;Zhang et al, 2021;Zhang et al, 2020b;Zhang et al, 2010;Zhang et al, 2018;Zhao et al, 2006;Zhao et al, 2009).…”

Treatment of Membrane Cleaning Wastewater from Thermal Power Plant Using Membrane Bioreactor

“…RO is a commonly used process to obtain demineralized water for high-pressure boiler operation in thermal power plants [4,5]. RO membrane pores are blocked by the inorganic scales and organic compounds step by step in the operation, which will cause the fouling of membranes [6,7]. In order to remove the foulants and recover the membrane flux, physical and chemical cleaning are suggested [8,9].…”