多环芳烃在石灰土和黑土轻组与重组有机质中的分配特征及生物有效性研究  

Distribution and bioavailability of polycyclic aromatic hydrocarbons in light-and heavy-fractions of Calcareous soil and Phaeozems

作　　者：陈艳[1,3] 魏然 陈卫锋[1,2] 倪进治[1,3] CHEN Yan;WEI Ran;CHEN Weifeng;NI Jinzhi(Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education,Fujian Normal University,Fuzhou 350007;Fujian Provincial Key Laboratory for Plant Eco-Physiology,Fujian Normal University,Fuzhou 350007;School of Geographical Science,Fujian Normal University,Fuzhou 350007)

机构地区：[1]福建师范大学湿润亚热带生态地理过程教育部重点实验室,福州350007 [2]福建师范大学福建省植物生理生态重点实验室,福州350007 [3]福建师范大学地理科学学院,福州350007

出　　处：《环境科学学报》2024年第8期437-445,共9页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.42077130)。

摘　　要：土壤有机质(SOM)是影响多环芳烃(PAHs)环境行为的重要因素,SOM可以区分为具有不同结构特征和周转速率的SOM组分,不同SOM组分中的PAHs的分配特征和生物有效性应该会有所不同,然而关于PAHs的生物有效性这方面研究还鲜见报道.本研究采用比重液(1.60 g·cm^(-3))和超声处理相结合的方法,将两种野外长期污染土壤石灰土和黑土分为轻组(LF)和重组(HF),对两种组分中PAHs的分配特征进行了研究,并利用微生物降解实验研究了LF和HF中PAHs的生物有效性.结果表明,石灰土和黑土LF中PAHs含量分别为136.86 mg·kg^(-1)和75.93 mg·kg^(-1),均远高于HF中9.01 mg·kg^(-1)和9.70 mg·kg^(-1)的PAHs含量.石灰土和黑土中LF的质量百分比分别为3.06%和9.19%,但它们结合的PAHs量占土壤PAHs总量的百分比分别为32.44%和44.21%.添加降解菌培养15 d后,石灰土LF中PAHs的平均降解率为15.83%,而HF中PAHs没有明显降解;黑土LF和HF中PAHs的平均降解率分别为24.24%和24.89%.研究结果表明了LF具有较强的PAHs富集能力,且PAHs的生物有效性也较高,在野外长期污染土壤的环境风险评估和修复中应予以重视.Soil organic matter(SOM)plays an important role in influencing the environmental behavior of polycyclic aromatic hydrocarbons(PAHs).SOM can be divided into different components based on structural characteristics and turnover rates,which may result in varying distribution and bioavailability of PAHs within these components.However,there has been limited research on the bioavailability of PAHs in this aspect.In this study,two types of long-term field-contaminated soils,Calcareous soil and Phaeozems,were separated into light fraction(LF)and heavy fraction(HF)using a specific gravity solution(1.60 g·cm^(-3))and ultrasonic treatment.The distribution patterns of PAHs in these two components were studied,and their bioavailability was assessed through microbial degradation experiments.The results showed that the PAH contents in the LF of Calcareous soil and Phaeozems were 136.86 mg·kg^(-1) and 75.93 mg·kg^(-1),respectively,which were significantly higher than those of 9.01 mg·kg^(-1) and 9.70 mg·kg^(-1) in the HF.Although the LF accounted for only 3.06%and 9.19%of the total soil mass in Calcareous soil and Phaeozems,respectively,they associated 32.44%and 44.21%of the total soil PAHs.After 15 days of incubation with degradation bacteria,the average degradation rate of PAHs in the LF was 15.83%,while no degradation of PAHs was observed in the HF of Calcareous soil.In Phaeozems,the average degradation rates of PAHs in the LF and HF were 24.24%and 24.89%,respectively.The results demonstrate that LF has a significant capacity to enrich PAHs and exhibits higher bioavailability of PAHs,which should be considered in the environmental risk assessment and remediation of long-term field-contaminated soils impacted by PAHs.

关 键 词：多环芳烃 有机质组分 分配特征 生物有效性 

分 类 号：X53[环境科学与工程—环境工程]