Effect of UV Irradiation and UV/Chlorine Processes on Trichloronitromethane Formation During Chlorination of Ronidazole

Abstract

The effect of UV irradiation and UV/chlorine processes on the formation of trichloromethane (CF) and trichloronitromethane (TCNM) from ronidazole (RNZ) disinfection was investigated in this study. Effects of reaction time, pH, and irradiation intensity on disinfection by‐product (DBP) formation were studied during chlorination, UV irradiation, and UV/chlorine processes. The formation potential (FP) of CF and TCNM increased with the increase of chlorination time and reached maximum of 50.6 and 5.0 µg/L, respectively, at pH 8. UV irradiation could increase CF and TCNM formation slightly during post‐chlorination, while the UV/chlorine process could increase the formation potential of TCNM significantly during post‐chlorination with short irradiation time and low UV intensity (e.g., FPTCNM = 459.4 µg/L; UV irradiation: 1.53 mW/cm2 for 20 min). Under UV condition, the formation of CF and TCNM with post‐chlorination increased with the increasing of pH. However, under UV/chlorine condition, the formation of TCNM reached the highest concentration under neutral condition. The DBP formation potential of RNZ during disinfection in the filtered drinking water was also detected. It turned out that disinfection of filtered drinking water with RNZ led to the formation of more DBPs (except the formation of TCNM in the UV/chlorine process) than ultra‐pure water with RNZ only.

Effects of amines on the formation and photodegradation of DCNM under UV/chlorine disinfection

“…When light intensity increased from 5 to 15 W, the increase percentage of DCNM formation from DMA was the largest (41.2%), followed by MA (34.4%), PolyDADMAC (28.8%). These phenomena were similar with the results reported by Wang's group, which described the formation of TCNM increased with the increase of UV irradiation intensity 41 . UV light irradiation played an important role in the formation of DCNM, in addition, the higher the light intensity of UV was, the faster the formation and photodegradation of DCNM was.…”

Microplastics as vector for persistent organic pollutants in urban effluents: The role of Polychlorinated Biphenyls

“…This MP-A appeared to be the microplastic with the highest specific surface area, i.e. 4.776 ± 2.151 m 2 /g, as determined in previous studies [8]. Besides this fact, the commercial facial cleanser containing these microbeads had titanium dioxide (TiO 2 ) in its composition.…”

“…They were selected attending their prevalence in major Spanish supermarkets, with a wide range of prices, from 39.67 up to 106.75 €/l, and aimed at both male and female audience. The extraction of microbeads has been previously published elsewhere [8]. Basically, it consists of a hot-water extraction in a 2 L beaker (60 rpm/30 min) with a final sieving step through a No.…”

“…After a previous characterization of sorption properties for PCB congeners in microbeads dispersed in bi-distilled water [8], studies were eventually carried out in treated urban effluents (TUE), in order to assess the PCB sorption capacity on microbeads after their use in personal care products, and their disposal in wastewater.…”

“…In this study, microbeads collected from four facial cleanser scrubs soap-based, with a well-known polymeric and additive composition, were tested for polychlorinated biphenyls (PCB) sorption in water effluents from the wastewater treatment plant (WWTP) 'Cabezo Beaza', located in Cartagena (Murcia, Spain). Previous analyses were carried out in bi-distilled water [8], in order to undertake an initial theoretical study to gain knowledge about the sorption behavior of these micropollutants.…”