高锰酸钾对土壤粒径组分中多环芳烃的氧化修复研究  

Oxidative remediation of polycyclic aromatic hydrocarbons in soil particle-size fraction by potassium permanganate

作　　者：胡思仪 罗大为 陈卫锋[1,2] 魏然[2,3] 倪进治[1,3] HU Siyi;LUO Dawei;CHEN Weifeng;WEI Ran;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5期466-473,共8页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.42077130)。

摘　　要：化学氧化能快速去除污染土壤中的多环芳烃(PAHs),但对土壤质量会产生较大的影响,特别是对土壤有机质(SOM)含量的影响.土壤是由不同粒径大小的团聚体组成,不同粒径组分中的SOM含量和结构不同,其富集的PAHs以及SOM被氧化剂氧化的程度可能也会不一样.将PAHs长期污染土壤分成粗砂粒(>105μm)、细砂粒(54~105μm)、粗粉粒(20~54μm)、细粉粒(2~20μm)和粘粒(<2μm)5个组分,研究了PAHs在不同粒径组分中的分配特征以及KMnO_(4)溶液(0.2、0.3和0.4 mol·L^(-1))对粒径组分中PAHs的氧化修复效果及其对土壤有机碳(OC)含量的影响.结果表明,不同粒径组分中PAHs含量的高低顺序为粗砂粒>细砂粒>粗粉粒>细粉粒>粘粒,占全土PAHs总量的百分比分别为45.64%、30.87%、15.07%、5.66%和2.77%.不同粒径组分中PAHs的氧化率和OC的损失率都随KMnO_(4)溶液浓度的增加而增加.粗砂粒、细砂粒、粗粉粒、细粉粒和粘粒中PAHs氧化率范围分别为30.46%~36.81%、21.37%~25.01%、9.31%~12.23%、3.68%~4.51%和2.18%~2.57%,OC损失率范围分别为0.37%~7.78%、1.98%~6.39%、0.27%~1.79%、3.63%~6.14%和4.32%~8.79%.随着土壤粒径的减小,KMnO_(4)溶液浓度的增加对PAHs氧化率提高的程度越来越小,但OC的损失率越来越大.在0.2 mol·L^(-1)KMnO_(4)溶液氧化下,粗砂粒和细砂粒(>54μm组分)中PAHs的氧化量之和占全土的51.47%,OC损失量之和占全土的2.35%;粗粉粒、细粉粒和粘粒(<54μm组分)中PAHs的氧化量之和占全土的15.16%,OC损失量占全土的8.22%.并且,粒径组分中OC损失率与其PAHs含量之间呈显著性负相关(p=0.048).综合PAHs在土壤粒径组分中的分配以及KMnO_(4)对PAHs氧化率和OC损失率来看,仅对>54μm粒径组分进行氧化修复既能降低土壤中PAHs的环境风险,又能保持OC含量,可以为PAHs污染土壤的化学氧化修复提供参考.Chemical oxidation can quickly remove polycyclic aromatic hydrocarbons(PAHS)from contaminated soils,but it can have a significant impact on soil quality,especially the content of soil organic matter(SOM).Soil is composed of aggregates of different particle sizes,and the content and structure of SOM in different particle-size fractions can vary.The degree of oxidation of the enriched PAHs and SOM by the oxidant may also differ.In this study,long-term PAH-contaminated soils were divided into five particle-size fractions:coarse sand(>105μm),fine sand(54~105μm),coarse silt(20~54μm),fine silt(2~20μm),and clay(<2μm).The distribution characteristics of PAHs in different particle-size fractions and the oxidative remediation effects of KMnO_(4)solution(0.2,0.3 and 0.4 mol·L^(-1))on PAHs in the particle-size fractions,as well as their impact on soil organic carbon(OC)content,were investigated.The results showed that the order of PAH content in different particle-size fractions was as follows:coarse sand>fine sand>coarse silt>fine silt>clay,accounting for 45.64%,30.87%,15.07%,5.66%,and 2.77%of the total PAHs in the soil,respectively.When the KMnO_(4)concentrations were 0.2,0.3 and 0.4 mol·L^(-1),the oxidation rates of total PAHs in bulk soil were 62.05%,68.30%and80.00%,and the loss rates of OC were 12.06%,20.21%and 31.26%,respectively.The oxidation rates of PAHs and the loss rates of OC in different particle-size fractions increased with increasing concentration of KMnO_(4)solution.The ranges of PAH oxidation rates in coarse sand,fine sand,coarse silt,fine silt,and clay were 30.46%~36.81%,21.37%~25.01%,9.31%~12.23%,3.68%~4.51%,and 2.18%~2.57%,respectively.The ranges of OC loss rates were 0.37%~7.78%,1.98%~6.39%,0.27%~1.79%,3.63%-6.14%,and 4.32%~8.79%,respectively.As the soil particle size decreased,the increase in KMnO_(4)solution concentration had a diminishing effect on the improvement of PAH oxidation rates but led to larger OC loss rates.Under the oxidation of 0.2 mol·L^(-1)KMnO_4,the sum of the oxidation amount

关 键 词：多环芳烃 粒径组分 高锰酸钾 氧化修复 有机碳 

分 类 号：X53[环境科学与工程—环境工程]