长期污染土壤不同组分中多环芳烃的分布特征及其毒性当量  

Distribution Characteristics and Toxicity Equivalent of Polycyclic Aromatic Hydrocarbons in Different Soil Fractions of Long-term Contaminated Soils

作　　者：张文敏 王子淳 陈卫锋[1,2] 魏然[2,3] 倪进治[1,3] ZHANG Wenmin;WANG Zichun;CHEN Weifeng;WEI Ran;NI Jinzhi(Institute of Geography,School of Carbon Neutrality Future Technology,Fujian Normal University,Fuzhou 350117,China;Fujian Provincial Key Laboratory for Plant Eco-physiology,School of Carbon Neutrality Future Technology,Fujian Normal University,Fuzhou 350117,China;School of Geographical Sciences,School of Carbon Neutrality Future Technology,Fujian Normal University,Fuzhou 350117,China)

机构地区：[1]福建师范大学地理研究所,福州350117 [2]福建师范大学、福建省植物生理生态重点实验室,福州350117 [3]福建师范大学地理科学学院、碳中和未来技术学院,福州350117

出　　处：《亚热带资源与环境学报》2024年第1期61-69,共9页Journal of Subtropical Resources and Environment

基　　金：国家自然科学基金(42077130);福建省自然科学基金(2020J01189、2020J01140)。

摘　　要：土壤有机质(SOM)是影响多环芳烃(PAHs)土壤环境行为的重要因素,不同SOM组分的含量和结构不同,对PAHs的富集能力和环境风险的影响也应有所不同。结合比重和粒径分组方法,将4种长期污染土壤的SOM分成轻组有机质(LF)、粗矿物结合态有机质(CMAOM)(>53μm)和细矿物结合态有机质(FMAOM)(<53μm)3个组分,研究了15种PAHs在不同组分中的分配特征,并采用苯并[a]芘(BaP)毒性当量浓度(TEQ_(BaP))评估了LF、CMAOM和FMAOM中PAHs的环境风险。结果表明,4种土壤中15种PAHs总量的范围为3.78~16.96 mg·kg^(-1)。LF中PAHs总量的范围为128.23~355.78 mg·kg^(-1),分别为CMAOM(3.55~19.28 mg·kg^(-1))和FMAOM(1.80~13.83 mg·kg^(-1))的9.5~36.2倍和14.2~71.3倍。LF只占土壤质量的0.5%~3.5%,但其富集的PAHs却占原土PAHs总量的12.3%~61.8%。不同SOM组分对PAHs的富集能力存在差异,但富集的PAHs组成相似。在各SOM组分中,LF中PAHs的TEQ_(BaP)最高,分别是CMAOM和FMAOM的9.7~35.3倍和14.7~79.7倍。土壤中LF有机质的周转速率较快,其结合的PAHs环境风险也会相对较高,在PAHs污染土壤的环境风险评估和修复研究中应予以重视。Soil organic matter(SOM)plays a crucial role in influencing the environmental behavior of polycyclic aromatic hydrocarbons(PAHs)in soil.The content and structure of SOM in different soil components may vary,leading to different capabilities of PAH enrichment and environmental risks.Using a combination of density and particle size fractionation methods,the SOM in four long-term contaminated soils was divided into three fractions:light fraction organic matter(LF),coarse mineral-associated organic matter(CMAOM)(>53μm),and fine mineral-associated organic matter(FMAOM)(<53μm).The distribution characteristics of 15 PAHs in these organic matter fractions were investigated,and the environmental risks of PAHs in LF,CMAOM and FMAOM were assessed using the toxicity equivalent concentration of benzo\pyrene(TEQ_(BaP)).The results showed that the total contents of 15 PAHs ranged from 3.78 to 16.96 mg·kg^(-1)in the four soils.The total concentration of PAHs in LF ranged from 128.23 to 355.78 mg·kg^(-1),which was 9.5 to 36.2 times and 14.2 to 71.3 times higher than those in CMAOM(3.55 to 19.28 mg·kg^(-1))and FMAOM(1.80 to 13.83 mg·kg^(-1)),respectively.Although LF accounted for only 0.5%to 3.5%of the soil mass,the enriched PAHs in LF accounted for 12.3%to 61.8%of the total PAHs in the bulk soil.Different SOM fractions exhibited variations in their capabilities of PAHs enrichment,but the composition of the enriched PAHs was similar.Among the organic matter fractions,LF had the highest TEQ_(BaP)value for PAHs,which was 9.7 to 35.3 and 14.7 to 79.7 times higher than those in CMAOM and FMAOM,respectively.LF organic matter in soil has a relatively fast turnover rate,leading to relatively higher environmental risks of the associated PAHs.Therefore,special attention should be paid to the PAHs associated with LF during the environmental risk assessment and remediation of PAH-contaminated soil.

关 键 词：土壤 有机质组分 多环芳烃 分配特征 毒性当量 

分 类 号：X53[环境科学与工程—环境工程]