陕西省泾惠渠灌区土壤重金属污染累积趋势预测

在对泾惠渠灌区农业生态环境污染现状调查的基础上,以灌区土壤中Cd、Hg、Pb、Cr、As、Cu、Zn为评价因子,通过建立模型,预测和分析了施肥、灌溉等农事活动对土壤中重金属环境容量及累积趋势的影响。结果表明,从2007年到2050年,泾惠渠灌区耕层土壤中Cr增加了4.87%,As7.61%,Pb11.7%,Hg26.4%,Zn30.3%,Cd68.1%,Cu83.2%;各重金属元素的总静环境容量由大到小依次为Zn〉Pb〉Cu〉Cr〉As〉Hg〉Cd,其中Zn的环境容量高出Cd的270倍;灌区土壤用完现存容量所需要的时间Zn最短,只有52a,其次是Cu,为54a,Hg最长,可达572a,但就现存容量所占的比例来看,灌区土壤中As和Zn的现存容量所占比例最小。

The prediction of accumulation trend for soil pollution of heavy metals in Jinghuiqu irrigation district of Shaanxi

On the base of investigating pollution current situation of agro-ecological environment in Jinghuiqqu irrigation district of Shaanxi province,Cd、Hg、Pb、Cr、As、Cu and Zn are use as evaluation indicators,and environmental capacity and accumulation trend of heavy metals in soil that is influenced by agricultural activities,such as fertilizing and irrigating,and so on,are predicted and analyzes by building model.The conclusions are reached that amounts of heavy metals in cultivated horizon of soil from 2007 to 2050 has a increasing tendency.Contents of Cr,As,Pb,Hg,Zn,Cd and Cu have increased by 4.87%,7.61%,11.7%,26.4%,30.3%,68.1%,and 83.2%,respectively.The descending order of total environmental capacity of heavy metals is ZnPbCuCrAsHgCd,in which amount of Zn is higher 270 times than that of Cd.The shortest time for the irrigation district that existing environmental capacity of heavy metals has run out is 52 years,which is for Zn,and secondly is 54 yeas for Cu,and the longest is approximately 572 years for Hg.But according to the proportion of existing environmental capacity,the proportions of Zn and As are the smallest in soil.