摘要
采用无扰动、直压式GeoProbe钻机获取铬渣场地不同深度土层(表层至含水层)连续原位样品,应用便携式X射线荧光光谱仪(FPXRF)对土层样品中的铬进行现场测定,并与电感耦合等离子体原子发射光谱法测定值进行对比,分析FPXRF测试数据质量。实验结果表明,在优化的分析测试条件下,现场测试结果与实验室测试结果一致,FPXRF检出限为19.89 mg/kg。FPXRF现场测试的总铬与便携式分光光度计现场检测的六价铬结果揭示,渣堆区包气带和第一含水层均受到重金属铬污染,渣堆边缘区包气带中铬含量出现间歇性降低、升高的动态变化过程,含水层介质中总铬和六价铬浓度最高值分别达400 mg/kg、390.4 mg/kg,渣堆区深部土壤污染物由渣堆渗滤液垂向迁移导致;渣堆下游土层污染范围主要为第一含水层,由渣堆区深部土层中重金属铬在地下水侧向径流作用下迁移扩散导致。研究结果为工作区土壤和地下水环境风险评价及修复工程设计实施提供了参考依据。
This paper refers to a kind of instrument ＇field portable X-Ray fluorescence＇（FPXRF） and the Geoprobe soil sampler with which a chromium-residues contaminated site was surveyed, and concentrations of Cr in soil samples were ana-lyzed in-situ. Then the data determined were statistically compared with analytical results from traditional ICP-AES analysis in order to verify exactness of the data form FPXRF. It was showed that under the optimized testing condition, the in-situ test results of FPXRF were in agreement with those ofthe traditional laboratory test, and the detection limit was 19.89 mg/kg. In conclusion, in the Cr contaminated site total Cr and hexavalent Cr were detected in the vadose zone and first group aquifer,and the chromium content changed, characterized by a dynamic process of intermittent rise and fall; the maximum concentra-tions of Cr and hexavalent Cr in first group aquifer were 400 mg/kg and 390.4 mg/kg, respectively. Obviously, the deep soils beneath the chromium-residues site had beenpolluted by the Cr-containing leachate which vertically migrates downwards; and mainly the first group aquifer was contaminated, which was due to the side runoff diffusion effects of the groundwater. Hope-fully, the survey results could provide a reference for the environmental risk assessment of soils and shallow groundwater and the design of remediation of heavy metal contaminated site.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2017年第12期126-132,共7页
Environmental Science & Technology
基金
国家重点研发计划科技基础资源调查专项课题(2017FY100401)
中国地质调查局地质调查项目(12120115047901
DD20160310)
环保公益性行业科研专项(201309003)
保定市科学技术研究与发展计划项目(16ZN008)
关键词
铬
分布特征
迁移规律
污染场地
便携式X射线荧光光谱仪
现场检测
chromium
distribution characteristics
migration rule
contaminated site
portable XRF analyzer
in situ deter-mination
