Mechanistic inferences from empirical and LSER modeling approaches concerning sorption of organic compounds by pristine and aged PE microplastics
Chemosphere, cilt.368, 2024 (Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 368
- Basım Tarihi: 2024
- Doi Numarası: 10.1016/j.chemosphere.2024.143695
- Dergi Adı: Chemosphere
- Derginin Tarandığı İndeksler: Scopus
- Anahtar Kelimeler: Aging, LSER, Polyethylene, pp-LFER, QSAR, Sorption
- Orta Doğu Teknik Üniversitesi Adresli: Evet
Özet
This study investigates the effect of aging of polyethylene (PE) microplastics (MP) on its interaction with organic compounds (OCs). Initially, pristine PE MPs were subjected to UV-aging, followed by characterization of their chemical structure and thermal properties. UV-aging resulted in formation of new functional groups such as carbonyl (C[dbnd]O), –OH, and unsaturation, along with changes in crystallinity and melting temperature. Complimentary sorption experiments were conducted with a suite of environmentally significant and structurally related OCs i.e., phenol, 2,3,6-trichlorophenol, triclosan, 1,1,2,2-tetrachloroethane, tetrachloroethylene and hexachloroethane, using pristine and UV-aged PE MPs. In addition to the distribution coefficients (i.e., KPEW) obtained experimentally, relevant data from the literature was also gathered for the purpose of developing a poly-parametric linear free energy relationship (pp-LFER) model. Two models were developed for predicting sorption onto: (i) only UV-aged PE, yielding an R2 = 0.96, RMSE = 0.19 (n = 16), (ii) PE that has undergone various types of aging, yielding an R2 = 0.83, RMSE = 0.68 (n = 36). Lastly, a direct comparison was performed between two pp-LFERs developed for the interaction of the same OCs with pristine vs. aged PE (n = 7). In addition to the predictive strength, the system coefficients enabled mechanistic inferences to be made; such that while molecular volume or non-specific hydrophobic interactions govern OC-pristine PE interactions, polar interactions and H-bonding also play important roles for OC-aged PE interactions. Overall, findings suggested that changes of MP surfaces under environmentally relevant aging conditions indicated an impact on their interactions with OCs in the environment.