Distribution Characteristics and Ecotoxicity Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Hydrothermal Carbonization Products of Corn Stalks
Hongyu Si,
Ming Wang,
Chao Xiao,
Xiaomei Xie,
Junhua Gong,
Lijun Yang,
Lizeng Peng,
Arthur Ernest Koschany,
Xiuxiu Chen,
Hewei Yu,
Qiang Yao,
Jikai Lu
Affiliations
Hongyu Si
Shandong Provincial Key Laboratory of Biomass Gasification Technology, Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China
Ming Wang
Shandong Provincial Key Laboratory of Biomass Gasification Technology, Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China
Chao Xiao
Engineering Technology Institute, Jereh Environmental Management Company, Chengdu, 610041, China
Xiaomei Xie
Shikefeng Chemical Industry Co., Ltd, Linyi, 276000, China
Junhua Gong
Shikefeng Chemical Industry Co., Ltd, Linyi, 276000, China
Lijun Yang
Qingdao Guanbaolin activated carbon Co., Ltd, Qingdao, 266300, China
Lizeng Peng
Shandong Academy of Agricultural Sciences, Jinan 250100, China
Arthur Ernest Koschany
Shandong Provincial Key Laboratory of Biomass Gasification Technology, Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China
Xiuxiu Chen
Shandong Provincial Key Laboratory of Biomass Gasification Technology, Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China
Hewei Yu
Shandong Provincial Key Laboratory of Biomass Gasification Technology, Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China
Qiang Yao
Shandong Academy of Agricultural Sciences, Jinan 250100, China
Jikai Lu
College of Engineering, Ocean University of China, Qingdao 266100, China
Hydrothermal carbonization (HTC) of corn straw causes hydrolysis and pyrolytic reorganization of the carbon skeleton, leading to the formation of polycyclic aromatic hydrocarbons (PAHs). When used as a soil amendment, hydrothermal carbon can lead to soil contamination, increased biotoxicity, and potential harm to ecosystem health. To systematically evaluate PAHs formation mechanisms, single-factor experiments were carried out by treating corn straw under varying temperatures (180 to 300 °C) and durations (2 to 6 h) in a closed batch reactor. PAHs were quantified via gas chromatography-mass spectrometry (GC-MS) with deuterated internal standards. Results revealed that total PAHs concentrations increased by 409%, 66.5%, and 68.3% at 180 °C, 210 °C, and 240 °C (4 h and 2 h), respectively, attributed to intensified dehydration and aromatization reactions under subcritical conditions. Conversely, PAHs levels decreased by 80.4% and 78.1% at 270 °C and 300 °C (4 h and 2 h), likely due to thermal cracking of PAHs macromolecules into low-molecular-weight fragments. Prolonged treatment (6 h and 4 h) reduced PAHs by 62.9 to 70.8% at ≤240 °C, suggesting oxidative degradation pathways dominate over pyrolysis under extended residence time. Mechanistic analysis indicated that optimizing HTC at 270 °C for 4 h achieves a critical balance between carbonization efficiency and PAHs suppression, providing a feasible strategy to mitigate ecotoxicological risks of hydrothermal carbon in soil remediation.
