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Survey And Assessment On Heavy Metal Pollution Situation Of DongGuan's Vegetable Field & Correlation Study Between The Content Of Heavy Meatal In Vegetables And The Soil Environmental Parameters

Posted on:2009-09-17Degree:MasterType:Thesis
Country:ChinaCandidate:C ZhangFull Text:PDF
GTID:2121360248951670Subject:Plant Nutrition
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The results,which were obtained by survey and assessment on heavy metal pollution of DongGuan's vegetable field & correlation between the content of heavy meatal in vegetables and the physical and chemistry properties of soil,were as follows:The heavy metal pollution situation of soil in DongGuan's vegetable field is not well. The content of Pb,Cd,Cr,As and Hg all above and beyond the background value of GuangDong.53.7%of soil was Polluted by Heavy Metal and there was 25.9%Serious pollution.The most serious pollution element in soil was Cd,it's average pollution index exceeding four times the cordon.Except Hg,the average pollution index of other three heavy metals were all below the cordon.From the survey data,we can discovery that DongGuan's heavy metal pollution has not only spot pollution but also extent pollution.And the spot pollution was the most popular form.Survey data told us that,all the irrigation water was suffering from heavy metal pollution,As was the most serious pollution element,the exceeding standard rate is 58.2%.Sewageirrigation and wastewater direct pipe in field were the pollution sources.Survey data showed that the heavy metal pollution rate in vegetables is 90.0%,but lots of vegetables's heavy metal content was below the limit value.Hg pollution was the lightest of all.In Ipomaea aquatica Forsk,As pollution was a outstanding problem,the pollution index is 0.19 which is out of 5 times than in other vegetables.According to the degree of comprehensive pollution index,the result is:Ipomaea aquatica Forsk.>Amarantus mangostanus L.>Lactuca sativa>Lactuca sativa Var.>Brassica chinensis L.>Brassica chinensis.The daily intakes of heavy metal in vegetable per capita in DongGuan were less than ADI(Allow Daily Intakes).However,the daily intakes of Pb and Cd were out of 15.0%of ADI,and As also was 8.8%of ADI.This will be most likely harmful to human health.Correlation analysis showed that,all of heavy metals in soil exist correlation,There was a very significant correlation between Pb,Cr and As;Cr and Hg also has a very significant correlation.Between heavy metal and the soil environmental parameters had significant correlation too. According to the correlation analysis we can discover that,between the content of heavy meatal in vegetables and the soil environmental parameters had linear correlation, Between pH and Cd in vegetables,Hg and rapidly available phosphorus,Pb and soil texture all had very significant correlation.And besides,all of heavy metal in vegetable had correlation too,as an example,there was a very significant correlation between Pb and Cd in vegetables.There was a very well linear correlation between the content of heavy meatal in vegetables and the soil environmental parameters,we used it building a trustworthy regression equation.
Keywords/Search Tags:soil, irrigation water, vegetable, content of heavy metal, survey, assessmen, soil environmental parameters, correlation
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