The relevance of interaction of chemicals/pollutants and microplastic samples as route for transporting contaminants

Catégorie : Impacts de la Pollution Plastique
Date :29 juin 2020
Godoy, V.; Martín-Lara, M. A.; Calero, M.; Blázquez, G.
Process Safety and Environmental Protection : 138, 312–323 (2020).
Microplastics have been converted a very important issue during current time. In addition, their capacity to adsorb other pollutants implies an additional problem. In this work, the potential of five types of microplastics derived from plastic waste, that include polyethylene, polyethylene terephthalate, polypropylene, polystyrene and polyvinyl chloride, to act as transporters of amoxicillin, atrazine, diuron, paracetamol, phenol and vancomycin was studied. Results suggested that microplastics, especially polyethylene, polyethylene terephthalate, polystyrene and polyvinyl chloride, revealed an essential protagonist as carriers of amoxicillin and phenol. The kinetic study showed that the sorption processes (from water to plastic) was slow and needs more than 28 days (amoxicillin) or about 21 days (phenol) to reach equilibrium. The modelling of equilibrium showed a better fit of the Langmuir model. The maximum Langmuir sorption capacities reached values between 4.03 and 8.80 mg/g for amoxicillin and between 1.25 and 2.80 mg/g for phenol. With respect to release tests, the liberation of the loaded pollutants was minor at the lower tested temperature (T =25 degrees C) and lower tested pH (pH = 2). Percentage of chemicals released increased between 1.3 and 7.9 times as the temperature increased until 40 degrees C. Similarly, the results revealed that release was greatly pH dependent. In these experiments, a singular behaviour was observed for amoxicillin at 25 degrees C, a combined effect of adsorption-release seems happen.