The Effects On Heavy Metals In Cow Manure By Disposition Of Penthetria Sp. And Eisenia Fetida

Cow manure is an important organic fertilizer.March fly(Penthetria sp.)and earthworm(Eisenia fetida)are considered to be excellent candidates to converse polluted cow manure into sustainably utilized resource.In this research,we studied the content and morphology of Cadmium(Cd),Plumbum(Pb)and Chromium(Cr)contained in cow manure which has been conversed by march fly or earthworm.The main research results are as follows:The highest percentage of granularity of cow manure which has been conversed by march fly is mesh number between 20-6,34.54%,secondly is mesh number between 6-3,23.64%,then is mesh number between 40-20,21.82%,next is bigger mesh number 3,15.43%,the less is smaller than mesh number 40,4.57%.The percentage of granularity of cow manure which has been conversed by earthworm in mesh number between 20-6,between 40-6,smaller than 40,between 6-3,bigger 3,is 36.01%,25.18%,14.66%,14.65%,9.49%,respectively.Dissect the march fly and detect the heavy metal of epidermis,fat body and intestinal.The content of Cd in epidermis,fat body and intestinal is 2.74,1.49,1.10 mg/kg.The fat body have the highest content of Pb,is 5.50 mg/kg,the content in epidermis is 2.69 mg/kg,not detect in intestinal.The content of Cr of epidermis>fat body> intestinal,the content are 38.64,33.30,19.77 mg/kg,respectively.The exchangeable form of Cd is the only form can be detected in march fly,the earthworm can be detected exchangeable form,reduction state and oxidation state,is 74.91%,20.70%,4.39%,respectively.The percentage of reduction state of Pb in the march fly is 65.90%,the oxidation state is 34.10%.The percentage of reduction state of Pb in the earthworm is 77.69%,the oxidation state is 22.31%.The percentage of residual form of Cr in march fly is 72.02%,the oxidation state is 18.04%,the reduction state is 9.94%.The percentage of residual form of Cr in earthworm is 69.20%,the exchangeable form is 17.49%,the reduction state is 13.31%.The cow manure which has been conversed by march fly and earthworm,about Cd,exchangeable form and reduction state can be detected in the former,the percentage is 63.14%,36.88%,respectively.The latter can detected the exchangeable form,residual form,reduction state,the percentage is 35.46% 、 34.28% 、 30.26%,,respectively.In the former,we can detect the oxidation state and reduction state of Pb,the percentage is 74.13%、25.87%,respectively.The percentage of oxidation state,reduction state and residual form of Pb in the latter is 52.79%、39.60%、7.61%,respectively.About Cr,residual form,reduction state,oxidation state,and exchangeable form can be detected in the former,the percentage is 61.06%、22.20%、15.05%、1.70%,respectively.The latter can detected the oxidation state、reduction state、exchangeable form,the percentage is 66.84%、25.62%、7.55%,respectively.Both march fly and earthworm have capability in reducing the granularity of cow manure and reduce the content of Cd,Pb and Cr in cow manure remarkably.And the earthworm has stronger capability in accumulation all this three heavy metals.March fly and earthworm change the state of heavy metals in cow manure,but have the different effect on the different metal.It is degrading bacteria which has highly relative abundance in the mutual intestinal microorganisms of march fly and earthworm.And The function of Leucobacter is Cr reduction.