Assessment of C-DBP and N-DBP formation potential and its reduction by MIEX® DOC and MIEX® GOLD resins using fluorescence spectroscopy and parallel factor analysis

This study investigated the applicability of parallel factor analysis (PARAFAC) of fluorescence excitation-emission matrices (EEM) spectra to assess the formation potentials (FP) of carbonaceous and nitrogenous disinfection byproducts (C-DBP and N-DBP) and the FP reduction by the magnetic ion exchange resins, MIEX (R) DOC and MIEX (R) GOLD. Two source waters of different nature - a surface water and a secondary treated wastewater effluent - were studied. The samples were analyzed for formation potentials of trihalomethanes (THM4), haloacetonitriles (HAN(4)), haloketones (HK2), and chloropicrin (CPN). A 4-component PARAFAC model was developed from 150 EEM samples generated from the raw source waters and their treatment with MIEX(R) resins. Components C1, C2, and C3 corresponded to humic-like dissolved organic matter (DOM) while C4 corresponded to protein-like DOM. Both MIEX(R) resins preferentially removed components C1, C2, and C3 over C4, indicating affinity with humic materials. MIEX(R) resins were shown to be more effective to treat surface water than secondary effluent, including effective removal of DBP precursors with extended bed volume treatment. Among all parameters investigated, THM4-FP strongly correlated with humic-like component C3, while HAN(4)-FP strongly correlated with protein-like component C4 (rho > 0.89 and p < 0.01); CPN-FP and HK2-FP both correlated with anthropogenic DOM C2 (rho > 0.89 and p < 0.01). Our results indicate that EEM-PARAFAC was valuable for assessing DBP formation potentials and removal of their precursors by MIEX(R) resins in different water sources. (C) 2020 Elsevier Ltd. All rights reserved.