Insights into the effect of hydrochar-derived dissolved organic matter on the sorption of diethyl phthalate onto soil: A pilot mechanism study

Hu Cheng; Yue Zhou; Jingzi Beiyuan; Xiaona Li; Ju Min; Lianghu Su; Longjiang Zhang; Rongting Ji; Jianming Xue

doi:10.1016/j.scitotenv.2023.169101

Insights into the effect of hydrochar-derived dissolved organic matter on the sorption of diethyl phthalate onto soil: A pilot mechanism study

Sci Total Environ. 2024 Feb 20:912:169101. doi: 10.1016/j.scitotenv.2023.169101. Epub 2023 Dec 8.

Authors

Hu Cheng¹, Yue Zhou², Jingzi Beiyuan³, Xiaona Li⁴, Ju Min⁵, Lianghu Su², Longjiang Zhang², Rongting Ji⁶, Jianming Xue⁷

Affiliations

¹ Nanjing Institute of Environmental Science, Ministry of Ecology and Environment of the People's Republic of China, Nanjing 210042, PR China; Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, PR China.
² Nanjing Institute of Environmental Science, Ministry of Ecology and Environment of the People's Republic of China, Nanjing 210042, PR China.
³ School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, PR China.
⁴ Research Center of Low-carbon Technology and Sustainable Development, School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, PR China.
⁵ State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China.
⁶ Nanjing Institute of Environmental Science, Ministry of Ecology and Environment of the People's Republic of China, Nanjing 210042, PR China. Electronic address: jirongting@nies.org.
⁷ Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, PR China; New Zealand Forest Research Institute (Scion), Christchurch 8440, New Zealand.

PMID: 38072267
DOI: 10.1016/j.scitotenv.2023.169101

Abstract

Biowaste-derived hydrochar is an emerging close-to-natural product and has shown promise for soil improvement and remediation, but the environmental behavior of the dissolved organic matter released from hydrochar (HDOM) is poorly understood. Focusing on the typical mulch film plasticizer diethyl phthalate (DEP), we investigated the effect of HDOM on the sorption behavior of DEP on soil. The relatively low concentration of HDOM (10 mg L^-1, 25 mg L^-1) decreases the sorption quantity of DEP on soil, while it increases by a relatively high concentration, 50 mg L^-1. The transformation from multilayer to monolayer sorption of DEP on soil occurs as the concentration of HDOM increases. The tryptophan-like substance is the main component of HDOM sorbed to soil, reaching 49.82 %, and results in competition sorption with DEP. The soil pores are blocked by HDOM, which limits the pore filling and mass transfer of DEP, but partitioning is significantly enhanced. The surface functional groups in HDOM are similar to those in soil, and chemical sorption, mainly composed of hydrogen bonding, exists but is not significantly strengthened. We identified the specific impact of HDOM on the sorption of organic pollutants on soil and provide new insights into the understanding of the environmental behavior of hydrochar.

Keywords: Dissolved organic matter; Hydrochar; Immobilization; Phthalate esters; Soil.