北京市菜地土壤重金属现状分析与评价

发布时间：2019-03-16 15:04

【摘要】：近年来北京蔬菜种植业得到迅速发展,已成为农业经济的支柱产业之一。为了解北京地区菜地以重金属为主要指标的土壤环境质量现状,采集北京市主要蔬菜生产区表层土壤(0~20cm),测定镉(Cd)、铅(Pb)、铜(Cu)、铬(Cr)、锌(Zn)、镍(Ni)、汞(Hg)含量和基础理化性质。依照《土壤环境质量标准》和《土壤环境监测技术规范》采用单项和综合污染指数法进行评价,结果表明,与土壤背景值相比,大兴、昌平、密云、延庆、房山、顺义、通州区内Cd、Cr明显富集,顺义区、房山区Cd质量分数平均值接近于《食用农产品产地环境质量评价标准》限量值(0.40 mg/kg),但未超过《土壤环境质量标准》中二级限量值(0.60 mg/kg)。Cd、Cu、Zn、Cr单项污染指数平均值处于0.7~1.0,属于尚清洁(警戒限)水平,且土壤Cd质量分数变异系数极高,40%以上样点存在"轻度"和"中度"污染,设施菜地较裸露菜地相比存在较高Cd污染风险。综上,北京市菜地土壤重金属环境质量指标总体安全,处于非污染状态,但存在一定程度的Cd、Cr、Cu、Zn累积污染风险。
[Abstract]:In recent years, Beijing vegetable planting industry has been developed rapidly, has become one of the pillar industries of agricultural economy. In order to understand the present situation of soil environmental quality with heavy metals as the main index in vegetable fields in Beijing, the topsoil (0~20cm) of main vegetable production areas in Beijing was collected and CD (Cd), Pb (Pb), Cu (Cu), Cr (Cr), Zn (Zn), was determined. Nickel (Ni), mercury (Hg) content and basic physical and chemical properties. According to the Standard for soil Environmental quality and the Technical Standard for soil Environmental Monitoring, the method of single and comprehensive pollution index was adopted. The results showed that Daxing, Changping, Miyun, Yanqing, Fangshan and Shunyi were compared with the soil background values. Cd,Cr was enriched obviously in Tongzhou area. The average content of Cd in Shunyi District and Fangshan District was close to the limit value (0.40 mg/kg), which was close to < Environmental quality Assessment Standard of Edible Agricultural products producing area > (0.40 mg/kg). However, it did not exceed the second level limit value (0.60 mg/kg) in the soil Environmental quality Standard. The average pollution index of CD and Cu,Zn,Cr was 0.7 脳 1.0, belonging to the level of cleanliness (warning limit). Moreover, the coefficient of variation of soil Cd content was extremely high, there were "mild" and "moderate" pollution in more than 40% of the samples, and there was a higher risk of Cd pollution in protected vegetable fields than in bare vegetable fields. On the whole, the environmental quality index of heavy metals in vegetable soil of Beijing is safe and non-polluting, but there is a certain degree of Cd,Cr,Cu,Zn cumulative pollution risk.
【作者单位】：北京市农林科学院植物营养与资源研究所;
【基金】：“十二五”国家科技支撑计划项目(2012BAD15B01) 北京市农林科学院科技创新能力建设专项(KJCX20150704)
【分类号】：X825

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