Characterization of dissolved organic matter from surface waters with low to high dissolved organic carbon and the related disinfection byproduct formation potential

Abstract

h i g h l i g h t s• The DBPFP of source waters did not correlate with the DOC value.• SUVA didn't represent the potential to form DBP in low-aromatic waters.• The Hi fraction played an important role in DBPFP for waters.• Phenolic hydroxyl group tended to form TCM and TCAA during chlorination.• Carboxyl and alcoholic hydroxyl groups tended to form DCAA and Br-DBP. g r a p h i c a l a b s t r a c tThe characterization of DBP precursors from three source waters in China revealed that the DBPFP did not correlate with the DOC value. The Ho fraction mainly contained phenolic hydroxyl and conjugated double bonds which were reactive with chlorine to produce DBP, especially TCM and TCAA. The Hi fraction may contain more amino, carboxyl and alcoholic hydroxyl groups, which had the great potential to form DCAA and Br-DBP during chlorination. a r t i c l e i n f o a b s t r a c tIn this study, the disinfection byproduct formation potential (DBPFP) of three surface waters with the dissolved organic carbon (DOC) content of 2.5, 5.2, and 7.9 mg/L was investigated. The formation and distribution of trihalomethanes and haloacetic acids were evaluated. Samples collected from three surface waters in China were fractionated based on molecular weight and hydrophobicity. The raw water containing more hydrophobic (Ho) fraction exhibited higher formation potentials of haloacetic acid and trihalomethane. The DBPFP of the surface waters did not correlate with the DOC value. The values of DBPFP per DOC were correlated with the specific ultraviolet absorbance (SUVA) for Ho and Hi fractions. The obtained results suggested that SUVA cannot reveal the ability of reactive sites to form disinfection byproducts for waters with few aromatic structures. Combined with the analysis of FTIR and nuclear magnetic resonance spectra of the raw waters and the corresponding fractions, it was concluded that the Ho fraction with phenolic hydroxyl and conjugated double bonds was responsible for the production of trichloromethanes and trichloroacetic acids. The Hi fraction with amino and carboxyl groups had the potential to form dichloroacetic acids and chlorinated trihalomethanes.

Formation and removal of disinfection by-products in a full scale drinking water treatment plant

“…This fraction, corresponding to compounds of relatively high molecular weight, is the main fraction removed by the coagulation step (reduction of around 90% of its UV absorbance in the SEC chromatogram; Figure 1d). These results are in good agreement with previous studies which have found good correlation with this particular fraction (Vasyukova et al 2013;Li et al 2014;Golea et al 2017). Assuming that the UV absorbance properties of humic substances (HS) are not significantly changed during coagulation, a lower reduction of THMFP (70%) compared to humic substances (90%) is observed, underlining the role of other organic fractions in addition to HS as THM precursors.…”

Partial renewal of granular activated carbon biofilters for improved drinking water treatment

“…These fluorescence peaks with emission <380 nm are generally attrib-uted to protein-like fluorescence while peaks with emission >380 nm are attributed to humic-like FDOM. [45][46][47][48] PARAFAC analysis revealed three independently-varying fluorescent components were present in the samples (Fig. 4).…”

Kesan Gabungan Aktiviti Guna Tanah dan Perubahan Musim terhadap Kualiti Sumber Air: Kajian Kes di Terusan Utara, Kedah

“…Gangguan antropologi terhadap permukaan tanah dan pengubahsuaian sistem sungai boleh memberi kesan negatif terhadap kualiti sumber air berkenaan (Hoo et al 2006;Li et al 2014;Panyapinyopol et al 2005;Shen et al 2014). Apabila sistem sungai terganggu, keseimbangan dinamik sungai akan terancam dan musnah (Chattopadhyay et al 2003).…”