摘要
针对干旱区气象和水文地质条件下,危废填埋场缓冲距离不明的问题,建立了渗滤液中污染物渗漏及其迁移转化的多过程模型,模拟污染物的稀释衰减过程,结合安全用水限值的确定,构建了缓冲距离计算框架,并选择典型场地开展案例研究.结果表明:不同类型的污染物需要的稀释与衰减倍数(RDAF)不同,有机物2,4-滴(2,4-D)的初始浓度大,毒性强,需稀释衰减667倍,是重金属As与Cd稀释衰减系数的6倍,不同污染物的稀释衰减倍数(DAF)与缓冲距离的敏感程度有关,有机物的DAF对缓冲距离更敏感.尽管2,4-D的DAF最大,但缓冲距离远小于重金属As与Pb的972m和942m.综合考虑所有污染物缓冲需求,干旱区典型危废填埋场的缓冲距离为972m,与常规认知相反,缓冲距离需求大于湿润地区而仅略小于海滨地区.进一步考虑了参数不确定性分析下95%置信区间的安全用水要求,缓冲距离需达到3465m.为满足敏感水源与填埋场缓冲距离的实际需求,对填埋废物采取预处理的方法优化缓冲距离.以As为例,通过预处理将其初始浓度从1.2mg/L降至1.02mg/L,缓冲距离可降至200m,说明干旱区缓冲距离需求对初始浓度更为敏感.
Aiming at the problem that the buffer distance of hazardous waste landfills was unknown under meteorological and hydrogeological conditions in arid areas,this paper establishes a multi-process model of pollutant leakage and migration transformation in leachate,simulates the dilution and attenuation process of pollutants,and constructs a framework for calculating buffer distances in combination with the determination of safe water use limits,and a typical site was selected for a case study.The results show that different types of pollutants require different dilution and attenuation factors(RDAF).The initial concentration of 2,4-drops(2,4-D)of organic matter was large and toxic,so it needs to be diluted and attenuated 667 times,which was 6 times the dilution and attenuation coefficient of heavy metals As and Cd.The dilution and attenuation factor(DAF)of different pollutants was related to the sensitivity of the buffer distance,and the DAF of organic matter was more sensitive to the buffer distance.Although the DAF of 2,4-D was the largest,the buffer distance was far less than 972m and 942m of heavy metals As and Pb.Considering the buffer demand of all pollutants,the buffer distance of typical hazardous waste landfills in arid areas was 972m.Contrary to conventional perception,the buffer distance demand was greater than that in humid areas and only slightly less than that in coastal areas.Further considering the requirement of safe water use with a 95%confidence interval under parameter uncertainty analysis,the buffer distance should reach 3465m.To meet the actual demand for buffer distance between the sensitive water source and the landfill site,the pretreatment method was adopted to optimize the buffer distance of landfill waste.Taking As as an example,the initial concentration of As was reduced from 1.2mg/L to 1.02mg/L through pretreatment,and the buffer distance could be reduced to 200m,indicating that the demand for buffer distance in arid areas was more sensitive to the initial concentration.
作者
吉栋梁
徐亚
黄兆琴
杜布云
赵曼颖
杨枫
JI Dong-liang;XU Ya;HUANG Zhao-qin;DU Bu-yun;ZHAO Man-ying;YANG Feng(College of Environment and Ecologic,Jiangsu Open University,Nanjing 210036,China;Chinese Research Academy of Environmental Sciences,Beijing 100012,China;School of Municipal and Environmental Engineering,Jilin Jianzhu University,Jilin 130118,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第2期712-721,共10页
China Environmental Science
基金
江苏省产学研合作项目(BY2021529)
国家重点研发计划项目(2020YFC1806304,2018YFC1800902)
国家自然科学基金资助项目(51708529)。
关键词
稀释衰减
缓冲距离
重金属
安全用水
dilution attenuation
buffer distance
heavy metal
safe water quality
