Development of novel experimental and modelled low density polyethylene (LDPE)-water partition coefficients for a range of hydrophobic organic compounds

Tengyi Zhu; Wenxuan Chen; Chad T Jafvert; Dafang Fu; Haomiao Cheng; Ming Chen; Yajun Wang

doi:10.1016/j.envpol.2021.118223

Development of novel experimental and modelled low density polyethylene (LDPE)-water partition coefficients for a range of hydrophobic organic compounds

Environ Pollut. 2021 Dec 15:291:118223. doi: 10.1016/j.envpol.2021.118223. Epub 2021 Sep 22.

Authors

Tengyi Zhu¹, Wenxuan Chen², Chad T Jafvert³, Dafang Fu², Haomiao Cheng⁴, Ming Chen², Yajun Wang⁵

Affiliations

¹ School of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China. Electronic address: tyzhu@yzu.edu.cn.
² School of Civil Engineering, Southeast University, Nanjing, 210096, China.
³ Lyles School of Civil Engineering, and Environmental & Ecological Engineering, Purdue University, West Lafayette, IN, 47907, USA.
⁴ School of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, Jiangsu, China.
⁵ School of Civil Engineering, Lanzhou University of Technology, 287 Langongping, Lanzhou, 730050, China.

PMID: 34583266
DOI: 10.1016/j.envpol.2021.118223

Abstract

Knowledge about partitioning constants of hydrophobic organic compounds (HOCs) between the polymer and aqueous phases is critical for assessing chemical environmental fate and transport. The conventional experimental method is characterized by large discrepancies in the measured values due to the limited water solubility of HOCs and other associated issues. In the current work, a novel three-phase partitioning system was evaluated to determine accurate low-density polyethylene (LDPE)-water partition coefficients (K_PE-w). By adding sufficient surfactant (Brij 30) to form the micellar pseudo-phase within the polymer/water system, the K_PE-w values were obtained from a combination of two experimentally measured values, that is, the micelle-water partition coefficient (K_mic-w) and the LDPE-micelle partition coefficient (K_PE-mic). The method presented here is capable of shortening the equilibration time to half a month, and avoiding defects of the traditional method with respect to directly measured aqueous phase concentrations. Herein, the K_PE-w values were determined for HOCs with little errors. Meanwhile, based on the 120 experimental K_PE-w data, several in silico models were also developed as valid extrapolation tools to estimate missing or uncertain values. Analysis of the underlying solubility interactions in the nonionic surfactant micelles were investigated, providing additional support for the reliability of the proposed method.

Keywords: HOCs; In silico models; LDPE-Water partition coefficients; Micelle-water partition coefficient; Surfactant.

MeSH terms

Hydrophobic and Hydrophilic Interactions
Organic Chemicals
Polyethylene*
Reproducibility of Results
Water*

Substances

Organic Chemicals
Water
Polyethylene