Evidence Hub

Adsorption of three pesticides on polyethylene microplastics in aqueous solutions: Kinetics, isotherms, thermodynamics, and molecular dynamics simulation

Li H, Wang F, Li J, Deng S, Zhang S

Chemosphere, 2021

Abstract

Microplastics could act as a carrier for pesticides in the water environment and pose a potential risk. This study mainly investigated the effects of reaction time, microplastics dosages, pH, and NaCl salinity on the adsorption characteristics of three pesticides (Imidacloprid, Buprofezin, Difenoconazole) on polyethylene (PE) microplastics in aqueous solution. The results showed that high pH and low NaCl salinity were conducive to the adsorption. The adsorption data were well fitted by the Freundlich isotherm model and the pseudo-first-order kinetics, indicating that it was mainly controlled by physical function. The adsorption capacity of three pesticides on PE microplastics followed the order of Difenoconazole > Buprofezin > Imidacloprid. The thermodynamic study indicated the adsorption of all pesticides as spontaneous and exothermic processes, and the elevated temperature was favorable to the adsorption. SEM-EDS and FTIR results verified that pesticides were adsorbed on the microplastics but the adsorption process was mainly controlled by intermolecular Van Der Waals Force and the microporous filling mechanism. Grand Canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulation results indicated that surface adsorption was the exclusive mechanism for the adsorption of pesticides on microplastics, and the final adsorption configurations revealed that there were complex interactions between the pesticide molecules and the C, H atoms in PE molecules. The results of…

How strong is the evidence?

Evidence Hub reads this as a simulation / modelling, done in computer models (in silico), not in people. Its evidence level is 5 of 5 (Very low · case / narrative / animal / in vitro / in silico). Case reports, narrative reviews, and animal, cell or computer-model studies give the weakest evidence for human health.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free