, Lončarski Maja, Tubić Aleksandra, Vasiljević Sanja, Agbaba Jasmina.

Microplastics (MPs) and chlorinated phenols (CPs) are ubiquitous contaminants in aquatic ecosystems. Therefore the study of organic pollution adsorption affinity toward different types of microplastics is vital for comprehensive assessment and risk management in the environment. Since microplastics may act as vectors for the transport of contaminants in water matrices main scope of this study was to understand adsorption behaviour of four CPs (4-chlorophenol-4-CP, 2,4-dichlorophenol-2,4-DCP, 2,4,6-trichlorophenol-2,4,6-TCP, and pentachlorophenol-PCP) on polyethylene of different origin (powdered standard polyethylene (PEp) and polyethylene isolated from two personal care products (PE<sub>P</sub>CPs₁ and PE<sub>P</sub>CPs₂)). All experiments were carried out in a Danube river water, and the initial concentration of selected CPs was 100 µg/l. The adsorption of selected chlorinated phenols on microplastic was determined by using kinetic and isotherm studies. The obtained results of the kinetic adsorption study indicated that the adsorption equilibrium between the CPs and polyethylene MPs was established after 24 h of contact time. In all cases, pseudo-second order kinetic model fitted data the best (R2=0.973-0.999) indicating that chemisorption is a dominant adsorption mechanism. A better understanding of the adsorption mechanism for chlorinated phenols on microplastic was determined by using Freundlich and Langmuir adsorption isotherms. Based on the obtained results Langmuir adsorption model fitted data better indicating that adsorption of the chlorinated phenols occurs at a specific site on the microplastics, with no further adsorption occurring at the same site. Maximum adsorption capacities determined by the Langmuir adsorption model also indicated that phisyco-chemical properties of the organic compound have the highest impact on adsorption behaviour in the case of chlorinated phenols toward microplastic. Therefore, the highest adsorption capacity was determined for 2,4-DCP (qmax=218.1 µg/g) and the lowest for PCP (qmax=189.0 µg/g). The results of this study also indicated that polyethylene MPs can serve for the transport of the chlorinated phenols through freshwater bodies.

View online