山西典型焦化场地特征污染物在非饱和带迁移规律及影响因素  

Study on the migration law and influencing factors of characteristic pollutants in the unsaturated zone of typical coking sites in Shanxi

作　　者：戎艳青 王林芳[3] 党晋华 RONG Yanqing;WANG Linfang;DANG Jinhua(Shanxi Agricultural University(Shanxi Agricultural University Academy of Sciences)College of Resources and Environment,Jinzhong,030600,China;Shanxi Ecological Environment Monitoring and Emergency Support Center(Shanxi Academy of Eco-Environmental Sciences),Taiyuan,030000,China;Sorghum Research Institute of Shanxi Agricultural University(Shanxi Academy of Agricultural Sciences),Jinzhong,030600,China)

机构地区：[1]山西农业大学(山西省农业科学院)资源环境学院,晋中030600 [2]山西省生态环境监测和应急保障中心(山西省生态环境科学研究院),太原030000 [3]山西农业大学(山西省农业科学院)高粱研究所,晋中030600

出　　处：《环境化学》2023年第12期4278-4291,共14页Environmental Chemistry

基　　金：国家重点研发计划项目(2020YFC1806500,2018YFC1803000)资助。

摘　　要：以山西某焦化场地为研究对象,以该场地污染最严重的苯和萘作为焦化行业特征污染物的代表,结合山西不同地区土壤含水量差异明显、年降雨量波动幅度大以及该场地存在碱性废水和酸性废液的无意倾倒导致土壤pH超标严重的特点.通过柱试验研究特征污染物苯、萘在非饱和带迁移规律及其关键影响因素;通过土水分离实验揭示多要素作用下特征污染物苯萘在土水介质中迁移特征.柱实验结果表明,苯在重力和淋洗作用下,不断向深层土壤扩散和迁移,越过渗透性差的粉土层,到达更深层的土层;而萘只有少部分不断向深层土壤扩散和迁移,大部分富集表层.降低土壤初始含水量会降低苯和萘在非饱和带迁移速率但是会促进迁移总量,并且增大降雨量、升高或降低淋滤液pH值会增强苯和萘向下迁移能力;降雨量、淋滤液pH值、土壤初始含水量都会影响非饱和带对苯和萘截留能力,其中土壤初始含水量影响最大,降雨量次之,淋滤液pH值最小;在相同环境因素下,与苯和萘残留量分布相关性最强的变量为采样深度,并且苯和萘残留量分布与采样深度相关系数值会随着环境因素的改变产生显著变化.土水分离实验结果表明淋滤液pH值是苯在土水介质中迁移的最大影响变量,影响萘在土水介质中迁移最大变量为降雨量.This study takes a coking site in Shanxi as the research object,and takes the most seriously polluted benzene and naphthalene as the representative of the characteristic pollutants in the coking industry.Combined with the obvious differences in soil water content in different areas of Shanxi,the large fluctuation of annual rainfall,and the unintentional dumping of alkaline wastewater and acidic wastewater in the site,the soil pH exceeded the standard.Study on the migration law of characteristic pollutants in the unsaturated zone and its key influencing factors by column test.The characteristics of the migration of characteristic pollutants in soil-water medium under the action of multiple factors were revealed through soil-water separation experiments.The results of the column experiments showed that reducing the initial soil water content would reduce the migration rate of benzene and naphthalene in the unsaturated zone but would increase the total amount of migration and increasing rainfall and increasing or decreasing the pH of the leachate would enhance the downward migration of benzene and naphthalene.Rainfall,leachate pH value and soil initial water content all affected the benzene and naphthalene retention capacity of the unsaturated zone.The soil initial water content has the greatest impact,followed by rainfall,and leachate pH value is the smallest.Under the same environmental factors,the variable with the strongest correlation with the distribution of benzene and naphthalene residues was the sampling depth,and the correlation coefficient between the distribution of benzene and naphthalene residues and the sampling depth would change significantly with the change of environmental factors.The results of the soil-water separation experiment showed that the pH value of the leachate was the largest variable affecting the migration of benzene in the soil-water medium,and the largest variable affecting the migration of naphthalene in the soil-water medium was rainfall.

关 键 词：焦化场地 非饱和带 迁移 土水介质. 

分 类 号：X131[环境科学与工程—环境科学]