APPROPRIATE TECHNOLOGIES TO COMBAT WATER POLLUTION Formation characteristics of carbonaceous and nitrogenous disinfection by-products depending on residual organic compounds by CGS and DAF Minsoo Maeng 1 & Nirmal Kumar Shahi 1 & Gwyam Shin 2 & Heejong Son 3 & Dongheui Kwak 4 & Seok Dockko 1 Received: 30 April 2018 /Accepted: 6 August 2018 # Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Allogenic organic matter (AOM) composed of extracellular and intracellular organic matter (EOM and IOM) is a major precursor of halogenated carbonaceous and nitrogenous disinfection by-products (C-DBPs and N-DBPs) upon chlorination. The EOM and IOM extracted from Microcystis aeruginosa were analyzed based on bulk parameters and organic fractions with different molecular weight by liquid chromatography with organic carbon detection (LC-OCD). It investigated the efficiency of a con- ventional gravity system (CGS) and dissolved air flotation (DAF) in the removal of organic precursors, together with measure- ment of the formation of four major trihalomethanes (THMs) and haloacetonitriles (HANs) in treated water upon chlorination. The results showed that EOM accounted for 59% of building blocks and humic substances, whereas for IOM, 54% were low molecular weight (LMW) neutrals. Both CGS and DAF showed 57–59% removal of dissolved organic carbon (DOC) from EOM and IOM. Regarding DON removal, DAF was found to be more effective, i.e., 8% higher than CGS for EOM. Moreover, the removal of LMW acids and neutrals (not easy to remove and are major precursors of DBPs) from EOM and IOM by DAF was higher than from CGS. The amounts of DBPs measured in all the samples treated for interchlorination were much lower than in the samples for prechlorination. Although the precursors of EOM had a higher concentration than in IOM, THMs and HANs were detected for IOM at a higher concentration, which might be attributed to higher amounts of aromatic, aliphatic moisture and protein compounds in the IOM. Comparatively, DAF showed lower THM and HAN values than CGS water, particularly for IOM. Also, DAF showed a sharp decrease in THMs and an insignificant increase in HANs according to time. Keywords Allogenic organic matter (AOM) . Extracellular organic matter (EOM) . Intracellular organic matter (IOM) . Carbonaceous and nitrogenous disinfection by-product (C-DBPs and N-DBPs) . Liquid chromatography with organic carbon detection (LC-OCD) Introduction Many lakes and reservoirs have undergone eutrophication, resulting in seasonal algal blooms. Harmful algal bloom in reservoirs frequently constrains the unit operation in drinking water treatment plants (DWTPs) because of the exponential rise in cell population and the concentration of allogenic or- ganic matter (AOM) (Henderson et al. 2008; Xie et al. 2013; Pivokonsky et al. 2016; Hua et al. 2017b). Algal cells often release intracellular toxins and odor compounds that severely threaten the quality of the water supply (Coral et al. 2013). When AOM occurs in an aquatic ecosystem, this autochtho- nous organic source contributes a substantial amount of or- ganic matter to the natural organic matter (NOM) (Tomlinson et al. 2016; Deng et al. 2017). This organic matter provides precursors for disinfection by-products (DBPs) formed when the water is subsequently chlorinated at the disinfection stage of the DWTPs. Carbonaceous DBPs (C-DBPs), such as tri- halomethanes (THMs) and haloacetic acids (HAAs), are formed when organic matter reacts with Cl. Nitrogenous DBPs (N-DBPs) such as haloacetonitriles (HANs) and halonitromethanes (HNMs) are also health concerns and have Responsible editor: Bingcai Pan * Seok Dockko dockko@dankook.ac.kr 1 Department of Civil and Environmental Engineering, Dankook University, Yongin-si, Gyeonggi-do 448-701, Republic of Korea 2 Department of Environmental Engineering, Ajou University, 206 world-cup-ro, Yeongtong-gu, Suwon-si 443-749, Republic of Korea 3 Water Quality Institute, Water Authority, Busan 614-854, Republic of Korea 4 Jeongeup Industry-Academic Cooperation Support Center, Chonbuk National University, 9 Cheomdan Rd, Jeongeup, Jeonbuk 56212, Republic of Korea Environmental Science and Pollution Research https://doi.org/10.1007/s11356-018-2919-9