TY - JOUR AB - Improved characterization of dissolved organic matter (DOM) in source waters used for drinking water treatment is necessary to optimize treatment processes and obtain high drinking water quality. In this study, seasonal differences in freshwater DOM composition and associated treatment-induced changes, were investigated at four drinking water treatment plants (DWTPs) in Sweden, during all seasons and a full-year. The objective was to understand how effectively DWTPs can adapt to seasonal changes and compare how optical and mass spectrometry methods detected these changes. In addition to bulk DOM analysis, this work focused on excitation-emission matrix (EEM) fluorescence including parallel factor (PARAFAC) analysis, and molecular level non-target analysis by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Overall, seasonal variability of raw water DOM composition was small and explained primarily by changes in the contributions of DOM with aromatic and phenolic moieties, which were more prevalent during spring in two surface water sources as indicated by absorbance measurements at 254 nm, computed specific ultraviolet absorbance (SUVA) and phenol concentrations. These changes could be balanced by coagulation, resulting in seasonally stable DOM characteristics of treated water. While EEM fluorescence and PARAFAC modelling effectively revealed DOM fingerprints of the different water sources, FT-ICR MS provided new insights into treatment selectivity on DOM composition at the molecular level. Future DOM monitoring of surface waters should target more specific seasonal DOM changes, such as features with a known impact on certain treatment processes or target certain events, like algal or cyanobacterial blooms. AU - Andersson, A.* AU - Powers, L.* AU - Harir, M. AU - Gonsior, M.* AU - Hertkorn, N. AU - Schmitt-Kopplin, P. AU - Kylin, H.* AU - Hellstrom, D.* AU - Pettersson, Ä.* AU - Bastviken, D.* C1 - 71109 C2 - 55910 CY - Thomas Graham House, Science Park, Milton Rd, Cambridge Cb4 0wf, Cambs, England TI - Molecular level seasonality of dissolved organic matter in freshwater and its impact on drinking water treatment. JO - Environ. Sci.: Water Res. Technol. PB - Royal Soc Chemistry PY - 2024 SN - 2053-1400 ER - TY - JOUR AB - The formation of disinfection by-products (DBPs) during drinking water treatment has been associated with various health concerns but the total DBP exposure is still unknown. In this study, molecular level non-target analysis by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used to study non-volatile DBPs, and how their composition changes during water distribution in four drinking water treatment plants (DWTPs) in Sweden using different types of raw water and disinfection processes. The largest portion of tap water DBP compositions were detected also at the DWTPs, highlighting that these DBP formulae were rather stable and contribute to human DBP exposure. Yet the number of detected DBPs decreased 14-48% between drinking water treatment and consumer taps in the three plants in which no mixing of water from other DWTPs in the distribution system occurred showing active DBP processing in the water distribution network. While considerable amounts of bromine-containing DBPs were detected upon chemical disinfection in some DWTPs, few of them were detected in the tap water samples, likely due to debromination by hydrolytic reactions. The overall fewer non-volatile DBPs detected in tap waters, along with changed distribution among chlorine and bromine DBPs, demonstrate that DBP mixtures are highly dynamic and that DBP measurements at DWTPs do not adequately reflect exposure at the point-of-use. Clearly, more knowledge about changes of DBP mixtures through the distribution system is needed to improve DBP exposure assessments. AU - Andersson, A.* AU - Gonsior, M.* AU - Harir, M. AU - Hertkorn, N. AU - Schmitt-Kopplin, P. AU - Powers, L.C.* AU - Kylin, H.* AU - Hellstrom, D.* AU - Nilsson, K.* AU - Pettersson, Ä.* AU - Stavklint, H.* AU - Bastviken, D.* C1 - 63364 C2 - 51298 CY - Thomas Graham House, Science Park, Milton Rd, Cambridge Cb4 0wf, Cambs, England SP - 2335-2345 TI - Molecular changes among non-volatile disinfection by-products between drinking water treatment and consumer taps. JO - Environ. Sci.: Water Res. Technol. VL - 7 IS - 12 PB - Royal Soc Chemistry PY - 2021 SN - 2053-1400 ER - TY - JOUR AB - Landfill leachate (LL) is a complex wastewater and an important potential source of environmental contamination. LL can contain high concentrations of ammonia, metals, other inorganic species, and dissolved organic carbon; however, bulk composition of dissolved LL organic matter (LLOM) is poorly understood. A better understanding of LLOM composition will inform treatment development and improve LL pollution tracing. In this study, we addressed this need for compositional and treatment information by characterizing LL from an active bioreactor municipal solid waste (MSW) landfill as well as from a closed MSW landfill. Through non-targeted ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) we were able to assign chemical formulas to thousands of singly charged molecular ions and compare samples to natural dissolved organic matter (DOM). LLOM was differentiated by a higher presence of sulfur-, nitrogen-, and chlorine-, particularly nitrogen-sulfur-, containing formulas. The abundance of chlorine-containing molecular formulas supports the existence of a non-volatile organochlorine component in MSW LL. We performed tandem MS (MS-MS) analyses to tentatively identify the presence of the flame retardant, chlorendic acid, and likely related compounds. Additionally, we measured contaminants of emerging concern (CECs) and other chemical parameters to further characterize LLs and found evidence suggesting a significant percent of Fe may be bound in Fe-organic complexes. AU - Martin, K.R.* AU - Robey, N.M.* AU - Ma, S.* AU - Powers, L.C.* AU - Heyes, A.* AU - Schmitt-Kopplin, P. AU - Cooper, W.J.* AU - Townsend, T.G.* AU - Gonsior, M.* C1 - 62241 C2 - 50615 CY - Thomas Graham House, Science Park, Milton Rd, Cambridge Cb4 0wf, Cambs, England SP - 1250-1266 TI - Characterization of landfill leachate molecular composition using ultrahigh resolution mass spectrometry. JO - Environ. Sci.: Water Res. Technol. VL - 7 IS - 7 PB - Royal Soc Chemistry PY - 2021 SN - 2053-1400 ER - TY - JOUR AB - Disinfection by-products (DBPs) are potentially toxic compounds formed upon chemical disinfection of drinking water. Controlling the levels and characteristics of dissolved organic matter (DOM) as precursor material for DBPs is a major target to reduce DBP formation. A pilot-scale treatment including suspended ion exchange (SIX (R)), a ceramic microfilter (CeraMac (R)) with in-line coagulation and optional pre-ozonation followed by granular activated carbon (GAC) filtration was compared with a conventional full-scale treatment based on DOM removal and DBP formation using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), rapid fractionation, liquid chromatography organic carbon detection (LC-OCD), adsorbable organic halogens (AOX) and trihalomethane (THM) analysis. The new treatment combination showed different selectivity for DOM removal, compared to the conventional, leading to changes in composition of the DBPs formed. SIX (R) and GAC had the largest impacts on reducing AOX and THM formation potentials but the high adsorptive capacity of GAC affected the diversity of detected DBPs most. Chlorination and chloramination of pilot treated water with doses normally used in Sweden produced low levels of AOX compared to the full-scale treatment, but FT-ICR MS revealed an abundance of brominated DBP species in contrast with the conventional treatment, which were dominated by chlorinated DBPs. This finding was largely linked to the high DOM removal by the pilot treatment, causing an increased Br-/C ratio and a higher formation of HOBr. Potential increases in Br-DBPs are important to consider in minimizing health risks associated with DBPs, because of the supposed higher toxicity of Br-DBPs compared to Cl-DBPs. AU - Andersson, A.* AU - Lavonen, E.* AU - Harir, M. AU - Gonsior, M.* AU - Hertkorn, N. AU - Schmitt-Kopplin, P. AU - Kylin, H.* AU - Bastviken, D.* C1 - 61140 C2 - 49636 CY - Thomas Graham House, Science Park, Milton Rd, Cambridge Cb4 0wf, Cambs, England SP - 779-794 TI - Selective removal of natural organic matter during drinking water production changes the composition of disinfection by-products. JO - Environ. Sci.: Water Res. Technol. VL - 6 IS - 3 PB - Royal Soc Chemistry PY - 2020 SN - 2053-1400 ER - TY - JOUR AB - Several areas around the world rely on seawater desalination to meet drinking water needs, but a detailed analysis of dissolved organic matter (DOM) changes and disinfection by-product (DBP) formation due to chlorination during the desalination processes has yet to be evaluated. To that end, DOM composition was analyzed in samples collected from a desalination plant using bulk measurements (e.g. dissolved organic carbon, total dissolved nitrogen, total organic bromine), absorbance and fluorescence spectroscopy, and ultrahigh resolution mass spectrometry (HRMS). Water samples collected after chlorination (e.g. post pretreatment (PT), reverse osmosis (RO) reject (brine wastewater) (BW), RO permeate (ROP), and drinking water (DW)), revealed that chlorination resulted in decreases in absorbance and increases in fluorescence apparent quantum yield spectra. All parameters measured were low or below detection in ROP and in DW. However, total solid phase extractable (Bond Elut Priority PolLutant (PPL) cartridges) organic bromine concentrations increased significantly in PT and BW samples and HRMS analysis revealed 392 molecular ions containing carbon, hydrogen, oxygen, bromine (CHOBr) and 107 molecular ions containing CHOBr + sulfur (CHOSBr) in BW PPL extracts. A network analysis between supposed DBP precursors suggested that the formation of CHOBr formulas could be explained largely by electrophilic substitution reactions, but also HOBr addition reactions. The reactions of sulfur containing compounds are more complex, and CHOSBr could possibly be due to the bromination of surfactant degradation products like sulfophenyl carboxylic acids (SPC) or even hydroxylated SPCs. Despite the identification of hundreds of DBPs, BW did not show any acute or chronic toxicity to mysid shrimp. High resolution MS/MS analysis was used to propose structures for highly abundant bromine-containing molecular formulas but given the complexity of DOM and DBPs found in this study, future work analyzing desalination samples during different times of year (e.g. during algal blooms) and during different treatments is warranted. AU - Powers, L.C.* AU - Conway, A.* AU - Mitchelmore, C.L.* AU - Fleischacker, S.J.* AU - Harir, M. AU - Westerman, D.C.* AU - Croué, J.P.* AU - Schmitt-Kopplin, P. AU - Richardson, S.D.* AU - Gonsior, M.* C1 - 60030 C2 - 49177 CY - Thomas Graham House, Science Park, Milton Rd, Cambridge Cb4 0wf, Cambs, England SP - 2521-2541 TI - Tracking the formation of new brominated disinfection by-products during the seawater desalination process. JO - Environ. Sci.: Water Res. Technol. VL - 6 IS - 9 PB - Royal Soc Chemistry PY - 2020 SN - 2053-1400 ER - TY - JOUR AB - Reactions between chemical disinfectants and natural organic matter (NOM) upon drinking water treatment result in formation of potentially harmful disinfection by-products (DBPs). The diversity of DBPs formed is high and a large portion remains unknown. Previous studies have shown that non-volatile DBPs are important, as much of the total toxicity from DBPs has been related to this fraction. To further understand the composition and variation of DBPs associated with this fraction, non-target analysis with ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was employed to detect DBPs at four Swedish waterworks using different types of raw water and treatments. Samples were collected five times covering a full year. A common group of DBPs formed at all four waterworks was detected, suggesting a similar pool of DBP precursors in all raw waters that might be related to phenolic moieties. However, the largest proportion (64-92%) of the assigned chlorinated and brominated molecular formulae were unique, i.e. were solely found in one of the four waterworks. In contrast, the compositional variations of NOM in the raw waters and samples collected prior to chemical disinfection were rather limited. This indicated that waterworks-specific DBPs presumably originated from matrix effects at the point of disinfection, primarily explained by differences in bromide levels, disinfectants (chlorine versus chloramine) and different relative abundances of isomers among the NOM compositions studied. The large variation of observed DBPs in the toxicologically relevant non-volatile fraction indicates that non-targeted monitoring strategies might be valuable to ensure relevant DBP monitoring in the future. AU - Andersson, A.* AU - Harir, M. AU - Gonsior, M.* AU - Hertkorn, N. AU - Schmitt-Kopplin, P. AU - Kylin, H.* AU - Karlsson, S.* AU - Ashiq, M.J.* AU - Lavonen, E.* AU - Nilsson, K.* AU - Pettersson, Ä.* AU - Stavklint, H.* AU - Bastviken, D.* C1 - 55997 C2 - 46689 CY - Thomas Graham House, Science Park, Milton Rd, Cambridge Cb4 0wf, Cambs, England SP - 861-872 TI - Waterworks-specific composition of drinking water disinfection by-products. JO - Environ. Sci.: Water Res. Technol. VL - 5 IS - 5 PB - Royal Soc Chemistry PY - 2019 SN - 2053-1400 ER -