贵州遵义松林Ni-Mo多金属矿区土壤砷、铊生态风险评价

发布时间：2018-10-07 18:33

【摘要】：本研究对贵州遵义松林Ni-Mo多金属矿区表层土壤(旱地土和水稻土)和主要农作物(粮食类和蔬菜类)进行系统采样,采用ICP-MS分析土壤样品中重金属As和Tl的含量,及农作物样品中Tl的含量。通过地质累积指数和潜在生态风险指数评价矿区土壤As和Tl污染状况及生态危害,并利用危险商法(HQ)评价直接摄入农作物对当地居民造成的Tl健康风险。主要研究结论如下:(1)矿区旱地土样品As含量范围为16.7~185 mg·kg~(-1),平均值为59.7mg·kg~(-1);水稻土样品As含量范围为6.4~44.6 mg·kg~(-1),平均值为22.4 mg·kg~(-1)。矿区旱地土样品Tl含量范围为1.04~4.69 mg·kg~(-1),平均值为2.11 mg·kg~(-1);水稻土样品Tl含量范围为1.12~1.93 mg·kg~(-1),平均值为1.57 mg·kg~(-1);(2)矿区6种农作物样品Tl含量的变化范围为0.0162~1.059 mg·kg~(-1)。粮食类作物(水稻、玉米、甘薯)的Tl含量均值为0.111 mg·kg~(-1),蔬菜类作物(白菜、辣椒、萝卜)的Tl含量均值为0.394 mg·kg~(-1)。(3)地质累积指数法的评价结果表明,矿区旱地土As的评价等级为无污染、轻度污染、中等污染、中度污染—重污染的样品分别占9.1%、13.6%、54.5%、18.2%、4.6%;矿区水稻土As的评价等级为无污染、轻度污染、中等污染的样品分别占41.7%、41.7%、16.6%。矿区旱地土Tl的评价等级为无污染、轻度污染、中等污染、中度污染—重污染的样品分别占5%、59%、27%、9%;矿区水稻土样品Tl的评价等级均为轻度污染。(4)潜在生态风险指数法的评价结果表明,矿区旱地土As的评价等级为轻微生态危害、中等生态危害、强生态危害的样品分别占45.5%、45.5%、9%;矿区水稻土As的评价等级均为轻微生态危害。矿区旱地土Tl的评价等级为中等生态危害、强生态危害、很强生态危害的样品分别占18%、64%、18%;矿区水稻土样品Tl的评价等级为中等生态危害和强生态危害的样品分别占33%和67%。(5)健康风险指数法的评价结果显示,辣椒、玉米、水稻的Tl健康风险指数小于1,不会引起人体健康风险;萝卜、白菜、甘薯的水稻的Tl健康风险指数大于1,长期食用会对人体造成一定程度的健康风险;6种农作物Tl健康风险排序为白菜萝卜甘薯水稻辣椒玉米。本研究的上述评价结果表明,矿区旱地土和水稻土中As和Tl已可能受到牛蹄塘组底部黑色页岩的风化及Ni-Mo矿产资源开采的影响,均存在一定程度的潜在生态风险。
[Abstract]:In this study, the surface soil (dryland soil and paddy soil) and main crops (grain and vegetables) in Ni-Mo polymetallic mining area of Zunyi pine forest in Guizhou province were systematically sampled. The contents of As and Tl in soil samples were analyzed by ICP-MS. And the content of Tl in crop samples. Through geological accumulation index and potential ecological risk index, the pollution status and ecological hazard of As and Tl in the soil of mining area were evaluated, and the Tl health risk caused by direct intake of crops to local residents was evaluated by (HQ). The main conclusions are as follows: (1) the range of As content in dryland soil of mining area is 16.7185 mg kg~ (-1), the average value is 59.7mg kg~ (-1), and the range of As content in paddy soil is 6.4 mg kg~ (-1) with an average of 22.4 mg kg~ (-1). The range of Tl content in dryland soil was 1.04 ~ 4.69 mg kg~ (-1), the average value was 2.11 mg kg~ (-1), and the range of Tl content in paddy soil was 1.120.93 mg kg~ (-1), and the average value was 1.57 mg kg~ (-1); (_ 2). The range of Tl content of 6 kinds of crop samples in mining area was 0.0162 ~ 2 ~ 1.059 mg kg~ (-1). The average Tl content of grain crops (rice, corn, sweet potato) was 0.111 mg kg~ (-1), and the average Tl content of vegetable crops (cabbage, pepper, radish) was 0.394 mg kg~ (-1). (3). The evaluation grade of As in dryland soil of mining area was no pollution, slight pollution, moderate pollution and heavy pollution, and the samples of medium pollution-heavy pollution accounted for 9.1C 13.6U 54.5N 18.2cm 4.6.The evaluation grade of As of paddy soil in mining area was non-pollution, mildly polluted, and the samples of moderate pollution accounted for 41.716.60.The results showed that the evaluation of As in dryland soil of mining area was non-polluted, slightly polluted, moderately polluted, and the moderately polluted samples accounted for 41.716.66% of the samples, respectively. The evaluation grade of Tl in dryland soil of mining area is no pollution, light pollution, moderate pollution, The Tl of paddy soil samples in mining area were all mild pollution. (4) the evaluation results of potential ecological risk index method showed that the evaluation grade of As in dryland soil of mining area was slight ecological hazard. The samples with strong ecological hazard accounted for 45.5%, and the As evaluation grade of paddy soil in mining area was slight ecological hazard. The evaluation grade of Tl in dryland soil of mining area is medium ecological hazard and strong ecological hazard. The samples with strong ecological hazards accounted for 18% and 18% respectively; the Tl of paddy soil samples from mining areas accounted for 33% and 67% of the samples with medium ecological hazard and strong ecological hazard respectively. (5) the results of the health risk index method showed that pepper and corn, The Tl health risk index of rice is less than 1, which does not cause human health risk. The Tl health risk index of sweet potato rice was more than 1, and the Tl health risk of 6 kinds of crops, namely cabbage, radish, sweet potato, rice, pepper and corn, caused a certain degree of health risk to human body after eating for a long time. The results of this study indicate that As and Tl in the dryland soil and paddy soil of the mining area may have been affected by the weathering of black shale at the bottom of Niulitang formation and the exploitation of Ni-Mo mineral resources, and there are some potential ecological risks.
【学位授予单位】：贵州师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53;X82

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