典型制革厂周边农田土壤重金属污染特征

Characteristics of heavy metal pollution on farmland soil surrounding representative tannery

为了评价关停了25年后某鞣制加工制革企业对周边农田土壤铬污染特征,对其附近101. 95 hm^2区域的348个农田表层土壤和121个水稻样品进行分析。根据土壤污染程度和农产品质量情况划分耕地土壤环境质量类别,将耕地划分为优先保护类和安全利用类进行分析。结果表明,鞣制加工制革企业附近农田土壤受到不同程度的铬污染,铬含量变化范围为33. 4～3 830 mg/kg,平均值为233. 4 mg/kg,铬含量远高于对照点的,也远远高于当地市土壤背景值,说明制革生产活动对土壤铬有累积的影响。农田表层土壤铬污染呈现沿排水沟沿线两侧分布,且距离排水沟越近的农田土壤污染越严重的规律。对被铬污染土壤的水稻糙米重金属的检测结果表明,糙米中铬的含量水平在0. 09～0. 12 mg/kg,符合《食品安全国家标准食品中污染物限量》(GB 2762-2017)的要求。调查区域优先保护类土壤面积和安全利用类土壤面积分别占调查区域总面积的91. 7%和8. 3%,调查区域内不存在严格管控类土壤。

To assess the characteristics of chromium pollution in the farmland surrounding the tannery shut down 25 years,348 surface soil samples and 121 rice samples from 101.95 hm 2 were analyzed.According to the degree of both the polluted soil and healthy rice,the priority protection soil area and safe use of soil area were classified.The results show that there is chromium(Cr)pollution in surfer soil surrounding tanning leather processing enterprises,and the content of Cr is ranged from 33.4 mg/kg to 3 830 mg/kg,with average of 233.4 mg/kg,which is higher than that of control samples and background samples from local place.It is suggested that Cr is accumulated on the soil surrounding tannery;and the Cr pollution of surface soil presents along the sides of their irrigation channel.The more closed to channel,the serious pollution of Cr in the farm land is.The Cr content in rice is ranged from 0.09 mg/kg to 0.12 mg/kg in the sampled from the Cr polluted soil,which is satisfy to the Food Health Standards(GB2762-2017).The priority protection soil area and safe use of soil area is 91.7%and 8.3%of the total area of survey area respectively,and there is no strict controlled soil survey area in the survey regional.