Potential of Adsorption of Diverse Environmental Contaminants onto Microplastics

Microplastics are regarded as vectors of hazardous contaminants due to their ability to adsorb xenobiotic chemicals. This has led to increased interest in the risk of previously neglected microplastic contaminants in the aquatic environment. Here, we assessed the possibility of transferring chemical contaminants to microplastics by evaluating the adsorption performance of (in)organic pollutants on various types of microplastics (polystyrene, PS; polyethylene terephthalate, PET; high-density polyethylene, HDPE; and low-density polyethylene, LDPE;). Considering the toxicity and polarity of each pollutant, dyes (BB9 and RR120) and heavy metals (Cd(II), Pb(II), As(III), and As(V)) were selected for the adsorption experiments. Dye was found to be adsorbed through physical adsorption. The adsorption capacity of microplastics for RR120 and BB9 was the highest for HDPE-1 and LDPE-1, respectively. Additionally, the smaller the size of the microplastics, the higher the adsorbed amounts. The main adsorption mechanism of heavy metals was found to be through physical and chemical adsorption. And adsorption mechanism of dye depends on physical adsorption. Thus, the adsorption of microplastic contaminants was affected more by the condition than by the type of microplastics.