TY - JOUR
T1 - Adsorption of phenanthrene and its monohydroxy derivatives on polyvinyl chloride microplastics in aqueous solution
T2 - Model fitting and mechanism analysis
AU - Bao, Zhen Zong
AU - Chen, Zhi Feng
AU - Zhong, Yuanhong
AU - Wang, Guangzhao
AU - Qi, Zenghua
AU - CAI, Zongwei
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China [grant number 91543202 ]; and the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program [grant number 2017BT01Z032 ].
PY - 2021/4/10
Y1 - 2021/4/10
N2 - The pervasiveness of microplastics, which can absorb pollutants, has a certain impact on pollutant migration in natural waters. Differences in functional groups, such as the hydroxyl group, of pollutants will affect their adsorption on microplastics. In this study, the adsorption of phenanthrene (PHE) or its monohydroxy derivatives, including 1-hydroxyphenanthrene (1-OHP), 2-hydroxyphenanthrene (2-OHP), 4-hydroxyphenanthrene (4-OHP), and 9-hydroxyphenanthrene (9-OHP), on polyvinyl chloride (PVC, measured mean particle size = 134 μm) microplastics was studied. The adsorption efficiency of PHE was shown to be higher than that of either of OHPs. A better fit for pseudo-second-order and Freundlich isotherm models was obtained, indicating different binding sites on the surface of PVC microplastics. The adsorption processes of PHE and OHPs on PVC microplastics were demonstrated to be exothermic and spontaneous. Combined with FT-IR analysis, theoretical calculation, and comparative adsorption experiments, hydrophobic interaction was the dominant mechanism during the adsorption process. In contrast, electrostatic repulsion, CH/π interaction, and halogen bonding played a minor role, to an extent, in the adsorption of PHE/OHPs on PVC microplastics. These findings indicate the influence of the hydroxyl group on adsorption and improve the understanding of interactions between PVC microplastics and PHE/OHPs.
AB - The pervasiveness of microplastics, which can absorb pollutants, has a certain impact on pollutant migration in natural waters. Differences in functional groups, such as the hydroxyl group, of pollutants will affect their adsorption on microplastics. In this study, the adsorption of phenanthrene (PHE) or its monohydroxy derivatives, including 1-hydroxyphenanthrene (1-OHP), 2-hydroxyphenanthrene (2-OHP), 4-hydroxyphenanthrene (4-OHP), and 9-hydroxyphenanthrene (9-OHP), on polyvinyl chloride (PVC, measured mean particle size = 134 μm) microplastics was studied. The adsorption efficiency of PHE was shown to be higher than that of either of OHPs. A better fit for pseudo-second-order and Freundlich isotherm models was obtained, indicating different binding sites on the surface of PVC microplastics. The adsorption processes of PHE and OHPs on PVC microplastics were demonstrated to be exothermic and spontaneous. Combined with FT-IR analysis, theoretical calculation, and comparative adsorption experiments, hydrophobic interaction was the dominant mechanism during the adsorption process. In contrast, electrostatic repulsion, CH/π interaction, and halogen bonding played a minor role, to an extent, in the adsorption of PHE/OHPs on PVC microplastics. These findings indicate the influence of the hydroxyl group on adsorption and improve the understanding of interactions between PVC microplastics and PHE/OHPs.
KW - Adsorption
KW - Hydroxyphenanthrene
KW - Mechanism
KW - Microplastic
KW - Phenanthrene
KW - Theoretical calculation
UR - http://www.scopus.com/inward/record.url?scp=85095785451&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2020.142889
DO - 10.1016/j.scitotenv.2020.142889
M3 - Article
C2 - 33138997
AN - SCOPUS:85095785451
SN - 0048-9697
VL - 764
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 142889
ER -