Trihalomethane formation potentials from the effluent of different wastewater treatment sources

Abstract

Reused wastewater is commonly treated with disinfection to remove pathogenic microorganisms; however, this process generates disinfection byproducts (DBPs), such as trihalomethanes (THMs). This study aimed to investigate the levels of THMs and THM formation potential (THMFP) in treated wastewater originating from different sources i.e., domestic, food-processing industry and hospital. The samples from each source were collected three times between June and August 2023. Dissolved organic carbon (DOC) was evaluated from the samples prior to and after disinfection with chlorine over a period of 7 days. The results found that the concentration of DOC was highest in hospital effluent, with an average value of 5.60±0.16 mg/L followed by effluent from the food-processing industry and domestic, which had average DOC concentrations of 4.60±1.39 mg/L and 4.46±0.37 mg/L, respectively. The concentration of THMs in hospital effluent was found the highest at 6.91±0.88 µg/L followed by effluent from the domestic and food-processing industries, which exhibited amounts of 6.74±0.77 µg/L and 5.25±0.77 µg/L, respectively. In contrast, the food-processing factory had the highest concentration of THMFP at 299.39±26.54 µg/L, while the domestic and hospital effluent displayed a lower concentration of 133.64±36.86 µg/L and 51.48±9.01 µg/L, respectively.