Formation of fatty acid methyl ester based microemulsion and removal mechanism of PAHs from contaminated soils

Xiaorong Zhang; Xiaoyong Liao; Zongqiang Gong; Xiaojun Li; Chunyun Jia

doi:10.1016/j.jhazmat.2021.125460

Formation of fatty acid methyl ester based microemulsion and removal mechanism of PAHs from contaminated soils

J Hazard Mater. 2021 Jul 5:413:125460. doi: 10.1016/j.jhazmat.2021.125460. Epub 2021 Feb 18.

Authors

Xiaorong Zhang¹, Xiaoyong Liao², Zongqiang Gong³, Xiaojun Li⁴, Chunyun Jia⁵

Affiliations

¹ Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China. Electronic address: zhangxiaorong191@mails.ucas.ac.cn.
² Land Contamination Assessment and Remediation Laboratory, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, PR China. Electronic address: liaoxy@igsnrr.ac.cn.
³ Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, PR China. Electronic address: zgong@iae.ac.cn.
⁴ Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, PR China. Electronic address: lixiaojun@iae.ac.cn.
⁵ Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, PR China. Electronic address: jiachunyun@iae.ac.cn.

PMID: 33930972
DOI: 10.1016/j.jhazmat.2021.125460

Abstract

Microemulsion (ME) is considered as a stable solution for adsorbing organic matters. Aiming to remediate PAH contaminated soils from industrial sites in Shijiazhuang (Soil CPS) and Beijing (Soil CSG) in China, novel MEs were designed with different ratios of mixed surfactants (Surf, TX-100+Tween 80), n-butanol and fatty acid methyl esters (FAMEs). Particle size, transmittance, surface intension, Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy of the MEs were analyzed. PAH removals by solubilization experiments were studied and regeneration of waste ME was evaluated. Results showed the novel MEs were obtained with particle sizes in a range of 18.53-122.77 nm. The lowest surface intension of MEs was 26.53 mN/m, which was prone to PAHs transferring to MEs. ‒OH (3350 cm^-1), ‒C˭C (1740 cm^-1) and ‒C‒O (1072 cm^-1) functioned in forming MEs. Additionally, ‒OH, C‒H, ‒C˭C, ‒C‒O were considered as active binding sites when remediating PAH soils. PAH removals in soils CPS and CSG were up to 90.1% and 89.7% with surfactants and co-surfactant (Surf:Co-s), (Surf:Co-s) and FAME, soil and MEs (w:v) at ratios of 1:1, 8:2 and 1:4, respectively. About 85.6% of FAME and 41.9% of TX-100 in waste ME were recovered for recycle purpose.

Keywords: FT-IR; MEs; PAHs removal; Raman; Recovery.

Publication types

Research Support, Non-U.S. Gov't