攀西某芒果产区土壤重金属污染评价

本研究以攀枝花市盐边县某芒果种植区为研究区,采集47个表层土壤(0~20 cm)样本,测试Cd、As、Cr、Cu、Ni和Pb 6种重金属元素含量。研究首先采用单因子污染指数法,然后采用内梅罗综合污染指数法和潜在生态危害指数法评价了采样区的土壤重金属污染程度,最后应用ArcGIS软件分析并绘制了研究区土壤污染程度空间分布图。结果表明：研究区Cd全部超标,As、Cu和Pb少量超标,仅Cr和Ni符合国家土壤环境质量标准要求。6种重金属含量的平均值均超过四川省土壤元素背景值；中部居民区附近Cd浓度较高,研究区北西侧、南西侧As浓度较高,中部Cr、Cu、Ni和Pb浓度高于东西两侧；单因子污染指数评价结果表明研究区Cd处于中度-重度污染,研究区As处于轻微污染；内梅罗综合污染指数评价结果表明研究区处于中度污染和重度污染的点位比例各占34.04%和65.96%；Cd、As、Cr、Cu、Ni和Pb单项潜在生态危害指数依次为980.069、18.486、1.983、5.005、6.285、4.640,综合潜在生态危害指数在777.344~924.348之间,总体呈现的潜在生态危害较强。研究表明,重金属Cd对芒果种植区的土壤环境存在一定威胁,建议采取措施进行防控。

Evaluation of Soil Heavy Metal Pollution in a Mango Producing Area in Panxi

Taking a mango planting area in Yanbian County of Panzhihua City as the research area, 47 surface soil (0~20cm) samples were collected to test the content of 6 heavy metals in Cd, As, Cr, Cu, Ni and Pb. Three methods were used to evaluated the degree of heavy metal pollution included the single factor pollution index method, the Nemero comprehensive pollution index method and the potential ecological hazard index method. ArcGIS software was used to analyze and draw the spatial distribution map of soil pollution degree in the study area. The result showed that the Cd in the study area exceeded the standard, and the As, Cu and Pb were slightly exceeded. Only Cr and Ni met the national soil environmental quality standards. The average value of the six heavy metals (mg.kg^-1) exceeded the background value of soil elements in Sichuan Province. Cd near the residential area in the middle of the study area was relatively high. The concentrations of As in the northwest and southwest of the study area were higher. Cr, Cu, Ni and Pb in the middle were higher than the east and west sides. The impact of single factor pollution index indicates that the Cd in the study area was in moderate-severe pollution and the As was slightly polluted. The Nemero comprehensive pollution index evaluation result showed that the study area was in moderate and severe pollution levels each accounted for 34.04% and 65.96%. The single potential ecological hazard indexes of Cd, As, Cr, Cu, Ni and Pb are 980.069, 18.486, 1.983, 5.005, 6.285 and 4.640, and the comprehensive potential ecological hazard index was between 777.344~924.348. The study area is generally strong potential ecological hazards. Cd posed a certain threat to the soil environment of mango planting area, suggesting that measures should be taken to prevent and control.