Adsorption behavior of triclosan on microplastics and their combined acute toxicity to D. magna

• Published in: The Science of the total environment Vol. 880; p. 163290
• Main Authors: Yoon, Soyeong, Lee, Jooyoung, Ko, Mingi, Jang, Taesoon, Lim, Kwang Suk, Kim, Hyun-Ouk, Ha, Suk-Jin, Park, Jeong-Ann
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.07.2023
• Subjects: Acute toxicity; Adsorption; Anti-Bacterial Agents; Microplastics; Microplastics - chemistry; Plastics - chemistry; Polystyrene; Triclosan; Triclosan - chemistry; Triclosan - toxicity; Water chemistry; Water Pollutants, Chemical - analysis; Water chemistry; Microplastics; Triclosan; Adsorption; Polystyrene; Acute toxicity
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.163290

Microplastics (MP) have been recently identified as emerging water contaminants in worldwide. Owing to its physicochemical properties, MP have been considered as a vector of other micropollutants and may affect their fate and ecological toxicity in the water environment. In this study, triclosan (TCS), which is a widely-used bactericide, and three frequently found types of MP (PS-MP, PE-MP, and PP-MP) were investigated. The adsorption behavior of TCS on MP was investigated by the effect of reaction time, initial concentration of TCS, and other water chemistry factors. Elovich model and Temkin model are the most fitted well with kinetics and adsorption isotherms, respectively. The maximum TCS adsorption capacities were calculated for PS-MP (9.36 mg/g), PP-MP (8.23 mg/g), and PE-MP (6.47 mg/g). PS-MP had higher affinity to TCS owing to hydrophobic and π-π interaction. The TCS adsorption on PS-MP was inhibited by decreasing concentrations of cations, and increasing concentration of anion, pH, and NOM concentration. At pH 10, only 0.22 mg/g of adsorption capacity was obtained because of the isoelectric point (3.75) of PS-MP and pKa (7.9) of TCS. And almost no TCS adsorption occurred at NOM concentration of 11.8 mg/L. Only PS-MP had no acute toxic effect on D. magna, whereas TCS showed acute toxicity (EC50,24h of TCS = 0.36 ± 0.4 mg/L). Although survival rate increased when TCS with PS-MP due to lower the TCS concentration in solution via adsorption, PS-MP was observed in intestine and body surface of D. magna. Our findings can contribute to understanding the combined potential effects of MP fragment and TCS to aquatic biota. [Display omitted] •Fragment PS-MP had higher affinity for TCS than PE-MP and PP-MP.•Presence of cations enhanced TCS adsorption on PS-MP, whereas anions inhibited it.•pH was not greatly affected TCS adsorption on PS-MP at the range of 3.3–7.4.•Almost no TCS adsorption occurred at NOM concentration of over 10 mg/L.•TCS-adsorbed PS-MP was found in the guts and body surface of Daphnia magna.