Adsorption behaviors of chlorpyrifos on UV aged microplastics

Both non-degradable and biodegradable plastics can act as vectors of diverse organic pollutants. In this study, two types of biodegradable microplastics [poly (butylene adipate-co-terephthalate) (PBAT) and polylactic acid (PLA)] and one type of non-degradable microplastics [polypropylene (PP)] were selected to investigate the impacts of ultraviolet (UV) irradiation for one month on microplastics surface modification and their adsorption behaviors for chlorpyrifos (CPF). The study revealed that PBAT held the largest adsorption capacity, and PLA held the fastest adsorption rate. The UV irradiation diminished the adsorption capacities on PLA and PP but enhanced the adsorption capacities on PBAT. The adsorption capacity normalized by specific surface area revealed that specific surface area was the dominant factor for affecting the adsorption capacities on PP and PLA after UV irradiation. These findings further clarify the interaction between CPF and microplastics, and provide a theoretical basis for assessing the ecological risk of microplastics in water.

Automated summary

Both biodegradable microplastics (PBAT and PLA) and non-degradable microplastics (PP) were studied for their surface modification and adsorption behaviors of CPF after one month of UV irradiation. PBAT showed the highest adsorption capacity while PLA exhibited the fastest adsorption rate. UV irradiation reduced the adsorption capacities of PLA and PP but enhanced the adsorption capacities of PBAT. Specific surface area was found to be the main factor affecting the adsorption capacities of PP and PLA after UV irradiation. These findings deepen the understanding of the interaction between CPF and microplastics, and provide a theoretical basis for evaluating the ecological risk of microplastics in water.