TCLP法对天津市农田重金属生态风险评价

Ecological Risk Assessment of Heavy Metals in Farmland with Toxicity Characteristic Leaching Procedure

TCLP法是用缓冲剂提取重金属的一种方法,该法评价重金属生态风险在美国已开展多年。利用TCLP法对天津市某农田土壤重金属进行生态风险评价,结果表明,在采集的23个样品中有效态铜、铅、锌、镉的含量范围为1.13-5.26、2.11-5.22、2.60-30.6、1.09×10^-3-77.9×10^-3mg/kg,普遍低于铜、铅、锌、镉在土壤中的总量（22.1-66.8、21.2-50.6、56.8-445、0.04-0.20 mg/kg）。镉的TCLP有效态与总量的差别最大。锌、铅存在轻微污染,污染率分别为21.7%、4.3%。

Abstact The method toxicity characteristic leaching procedure is using buffer solution to extract heavy metal from soil. TCLP has been used ecological risk assessment for many years. Ecological risk assessment of heavy metals in farmland in Tianjin by toxicity characteristic leaching procedure. The results show that of the 23 samples collected whole amount Cu, Pb, Zn, Cd determination of the range of 22.1 - 66.8,21.2 - 50. 6,56.8 - 445,0.04 - 0. 20 mg/kg. Available Cu, Pb, Zn, Cd content in the range 1.13 -5.26,2.11 - 5.22,2. 60 - 30. 6 mg/kg,1.09 ×10^-3 77.9 ×10^-3 mg/kg,where the amount of available Cd to total Cd accounted for the largest proportion. Single pollution index and comprehensive pollution index assessment similarly. Environmental quality evaluation results show that only minor Zn pollution,was 8.7%. Using the TCLP method of ecological risk assessment indicates,Zn and Pb there is a slight pollution, contamination rates were 21.7% ,g. 3%.