基于模糊数学的太原市敦化灌区污灌土壤重金属污染评价

SOIL HEAVY METAL POLLUTION EVALUATION OF DUNHUA SEWAGE IRRIGATION AREA BY FUZZY MATHEMATICS MODEL

采用原子吸收和原子荧光分光光度法测定了太原市敦化污灌区95个表层土壤样品的8种重金属含量,并对污灌土壤的pH值、阳离子交换量、容重等理化性质进行分析,在此基础上采用模糊数学方法评价了其土壤环境质量,探讨了灌区土壤重金属的分布特征及污染状况.结果表明,土壤重金属砷、铜、锌、镍、汞、铬和铅含量值都在国家二级标准值范围内,平均含量分别为6.165,39.198,114.758,37.225,0.171,28.249和37.468mg·kg-1,重金属镉的含量高于国家二级标准值,平均含量高达1.247mg·kg-1;敦化灌区土壤的平均pH值为8.01,属弱碱性土壤,平均阳离子交换量为80.96cmol·kg-1,表层土壤有机质含量在1.27%—2.18%之间;模糊数学评价结果得到灌区土壤环境质量为三级水平,各个采样点的污染程度为董家营村西>西谷乡东>王答乡南>孟封镇北>鹅池村南。

The content of heavy metals in top soil samples（95） from Dunhua sewage irrigation area was measured using AAS and AES.The physical property of the samples was also analyzed.The soil environmental quality was assessal by a fuzzy mathematical model,and the distribution and pollution characteristic of soil heavy metals were discussed.The results showed that the mean content of As,Cu,Zn,Ni,Hg,Cr and Pb in these top soil samples were 6.165,39.198,114.758,37.225,0.171,28.249and 37.468mg·kg-1,respectively.Content of Cd（1.247 mg·kg-1） was higher than the standard value;The average pH value of Dunhua irrigated soil was 8.01,the average cation exchange capacity was 80.96cmol·kg-1,organic matter content of surface soil was 1.27% —2.18% ;The soil environmental quality was of the third grade,Dong Village West was the most seriously polluted area by Fuzzy mathematical model,followed by West Valley Town,Wang Da South,Meng Feng Town and Goose Pond Village South.