| Abstract |
The characteristics of natural organic matter (NOM) in water sources may be significant for regulating NOM and limiting the production of disinfection by-products. NOM surrogate measures such as dissolved organic carbon (DOC), ultraviolet absorbance at a wavelength of 254 nm (UV-254), specific ultraviolet absorption (SUVA), and fluorescence excitation-emission (FEEM) were utilized to evaluate NOM qualities related to trihalomethanes (THMs) generation by chlorination from diverse water sources in the southern part of the Songkhla lake basin (SLB), such as the water sample of the reservoir (n = 3), the water well (n = 2), and the canal (n = 10). The canal had the highest DOC concentration (5.125.89 mg/L), followed by the reservoir (2.052.32 mg/L) and the well (2.122.23 mg/L). The results for the lowest SUVA values indicated that NOM was present in the water well and that aromatic proteins and SMP-like compounds predominated in the canal. The results of FEEM spectroscopy indicated that tryptophan-like chemicals (240 nmEx/360 nmEm and 260 nmEx/360 nmEm) were the predominant DOM in community wastewater discharged into the SLB compared to humic and fulvic acid-like substances (280 nmEx/410 nmEm, 340 nmEx/410 nmEm, 330 nmEx/440 nmEm). The highest concentration of THMs was found in the canal (560736 μg/L), followed by the water sample from the reservoir (146390 μg/L), and the lowest concentration was found in the water well (120312 μg/L). The reservoir had a significantly higher THMs/DOC ratio than the canal and the water well. The mixture of NOM originating from terrestrial and microbiological sources contributed to NOM fractions. Low molecular weight NOM, aromatic proteins, and water soluble microbial metabolites can all be used as reactants to make THM. |