Lurgi-Thyssen dust catalytic thermal desorption remediation of di-(2-ethylhexyl) phthalate contaminated soils

Shaohua Mao; Chiquan He; Zhenzhen Zhao; Feifei Wang; Xueping Chen; Xiaoyan Liu; Daoyuan Wang

doi:10.1016/j.jenvman.2022.117138

Lurgi-Thyssen dust catalytic thermal desorption remediation of di-(2-ethylhexyl) phthalate contaminated soils

J Environ Manage. 2023 Mar 15:330:117138. doi: 10.1016/j.jenvman.2022.117138. Epub 2023 Jan 7.

Authors

Shaohua Mao¹, Chiquan He², Zhenzhen Zhao¹, Feifei Wang¹, Xueping Chen¹, Xiaoyan Liu¹, Daoyuan Wang³

Affiliations

¹ College of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China.
² College of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China. Electronic address: cqhe@shu.edu.cn.
³ College of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China. Electronic address: dywang20@shu.edu.cn.

PMID: 36623387
DOI: 10.1016/j.jenvman.2022.117138

Abstract

Fe2O3-assisted pyrolysis has been demonstrated to be a cost-effective thermal desorption (TD) technology. Lurgi-Thyssen dust (LTD) is a type of steel slag waste that contains a large amount of Fe2O3. In this study, to reduce energy consumption, LTD was added to contaminated soil to evaluate the feasibility of enhancing the TD removal efficiency of di-(2-ethylhexyl) phthalate (DEHP). The DEHP removal rate increased by 22.39% after adding 2% LTD at 200 °C for 20 min. Because of the catalytic pyrolysis of LTD, DEHP was pyrolyzed to form three types of short-chain esters: mono-(2-ethylhexyl) phthalate (MEHP), di (2-methylbutyl) ester, and methyl 2-ethylhexyl phthalate. The pyrolysis products of DEHP were less toxic and did not affect soil reuse. When the DEHP removal rate was 87.10%, LTD addition decreased the temperature and residence time of TD and alleviated the effect of TD on the soil physicochemical properties. Additionally, the desorption of DEHP from soil fitted the pseudo-second-order kinetic model well. Thus, the addition of LTD to contaminated soil enhanced the efficiency of TD remediation. Moreover, this study could provide a practical and economical strategy for LTD reuse.

Keywords: Pyrolysis; Removal mechanism; Steel slag waste Lurgi-Thyssen dust; Waste recycling; di-(2-ethylhexyl) phthalate.

MeSH terms

Biodegradation, Environmental
Diethylhexyl Phthalate* / chemistry
Ferric Compounds
Phthalic Acids*
Soil
Soil Pollutants* / chemistry

Substances

phthalic acid
mono-(2-ethylhexyl)phthalate
Diethylhexyl Phthalate
Ferric Compounds
Soil Pollutants
Phthalic Acids
Soil