Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; Zhongke-Ji'an Institute for Eco-Environmental Sciences, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Ji'an 343000, China.
College of Environment and Safety, Taiyuan University of Science and Technology, Taiyuan 030024, Shanxi Province, China.
Ecotoxicol Environ Saf. 2021 Apr 15;213:112075. doi: 10.1016/j.ecoenv.2021.112075. Epub 2021 Feb 24.
Biochars were studied for their impacts on the dissipation and vegetable uptake of polycyclic aromatic hydrocarbons (PAHs) in an agricultural soil. The health risks of PAHs taken up by vegetables were assessed by growing Chinese cabbage in both unamended soil and biochar-amended soils. In the unamended soil, the total 16 PAHs (Σ16PAHs) content decreased by 77.38% after planting the vegetable. The dissipation percentages of low-molecular-weight PAHs (LMW-PAHs), medium-molecular-weight PAHs (MMW-PAHs), and high-molecular-weight PAHs (HMW-PAHs) were 82.37%, 72.65%, and 68.63%, respectively. A significant negative correlation was determined between the dissipation percentages of PAHs in soil and the logK of PAHs (p < 0.01), indicating that the affinity of PAHs for soil particles was one of an important limiting factors on the dissipation of PAHs. The uptake of PAHs by plant was significantly reduced with the increase in the molecular weight of the PAHs (76.55% for LWM-PAHs, 17.13% for MMW-PAHs, and 6.05% for HMW-PAHs). Addition of biochars to the soil decreased the dissipation of Σ16PAHs (73.59-77.01%), mostly due to a decrease in the dissipation of LMW-PAHs and MMW-PAHs. This finding was due to the immobilization of LMW-PAHs and MMW-PAHs within the biochar micropores. A marked reduction of Proteobacteria in biochar-amended soils also resulted in the decreased biodegradation of PAHs. Four of six biochars significantly increased the concentrations of Σ16PAHs in plant by 30.10-74.22%. Generally, biochars significantly increased the uptake of LMW-PAHs by plant but had little influence on the plant uptake of MMW-PAHs and HMW-PAHs. Three of six biochars notably increased the incremental lifetime cancer risk values based on the exposure of PAHs by vegetable consumption.
生物炭对多环芳烃（PAHs）在农业土壤中消解和蔬菜吸收的影响进行了研究。通过在未添加生物炭的土壤和添加生物炭的土壤中种植白菜来评估蔬菜吸收的 PAHs 的健康风险。在未添加生物炭的土壤中，种植蔬菜后，总 16 种 PAHs（Σ16PAHs）含量下降了 77.38%。低分子量 PAHs（LMW-PAHs）、中分子量 PAHs（MMW-PAHs）和高分子量 PAHs（HMW-PAHs）的消解率分别为 82.37%、72.65%和 68.63%。土壤中 PAHs 的消解率与 PAHs 的 logK 值之间存在显著的负相关性（p<0.01），表明 PAHs 与土壤颗粒的亲和力是限制 PAHs 消解的重要因素之一。随着 PAHs 分子量的增加，植物对 PAHs 的吸收显著降低（LWM-PAHs 为 76.55%，MMW-PAHs 为 17.13%，HMW-PAHs 为 6.05%）。向土壤中添加生物炭会降低 Σ16PAHs 的消解率（73.59-77.01%），主要是由于 LMW-PAHs 和 MMW-PAHs 的消解减少。这是由于 LMW-PAHs 和 MMW-PAHs 被固定在生物炭的微孔内。生物炭添加土壤中变形菌门的显著减少也导致了 PAHs 的生物降解减少。六种生物炭中有四种显著增加了植物中 Σ16PAHs 的浓度，增加了 30.10-74.22%。一般来说，生物炭显著增加了植物对 LMW-PAHs 的吸收，但对植物对 MMW-PAHs 和 HMW-PAHs 的吸收影响不大。六种生物炭中有三种显著增加了基于蔬菜消费暴露的 PAHs 的增量终生癌症风险值。
