بررسي اثرات كودسبز، كشت مخلوط و ريز و سفر گياهان ذرت و كلزا بر جزء بندي شيميايي و گياه پالايي سرب و روي در يك خاك آلوده

چكيده انگليسي :

Effects of Green Manure Mixed Culture and Rhizosphere of Corn and Canola on Fractionation and Phytoremediation of Lead and Zinc in a Contaminated Soil Yaser Azimzadeh Yaser azimzadeh@gmail com Date of Submission 2012 09 19 Department of Soil Science College of Agriculture Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Hosein shariatmadari shariat@cc iut ac ir Mehran shirvani shirvani@cc iut ac irAbstract Mobility bioavailability and the environmental risk of heavy metals is associated with the changes in theirchemical forms in soils Root induced changes affect distribution of heavy metals in various geochemical fractionsand bioavailability of heavy metals in soil Therefore it is necessary to get more information about behavior thechemical forms of heavy metals in soil and their relationship with plants Because few studies about the processesinvolved the heavy metals in the rhizosphere especially in the hyper accumulatore plants complicated relationshipof heavy metals with plants soil and microorganisms in the rhizosphere is not well known and understanding theseprocesses can provide us the useful information for refining heavy metals contaminated soils and disposal of theyrisk The aim of this study was assessing the changes of soil chemical properties and chemical forms andbioavailability of Lead Zinc Copper and Nikel by distance from root of corn and canola in single and mixed culturesystem and the effect of green manure on this changes and survey efficiency of phytoremediation potential of cornand canola in single and mixed culture system Therefore the rhizobox system was used and inside each box usingnylon mesh plates with holes of 45 micron was divided into four zones The plants were planted in the middlezone At the end of the growing season roots and shoots of plants was isolated and soil were taken from each areaseparately In order to determine the chemical forms of heavy metals sequential extraction method was used Theresults of the soil analysis showed that green manure and plant cultivation impressed soil chemical properties andchemical forms of heavy metals and also affected the efficiency of phytoremediation Exchangeable form of Zinc onthe rhizosphere and bulk soil was more than two middle zones Exchangeable fraction of lead and copper and theassociated organic matter fraction of copper in rhizosphere was more than bulk soil Related to organic matter andcarbonate fraction of copper and bioavailability of nickel decreased with distance from the root by the regularprocess While the bioavailability of zinc increased with distance from the root The associated organic materfraction of zinc and nickel and bioavailability of lead was highest in the near soil mass and was and lowest in thesoil mass The associated organic matter fraction of Lead and nickel in the rhizosphere was more than bulk soil Thecarbonate fraction of lead and nickel in the near rhizosphere zone was more than mass soil Oxide fraction of lead zinc and nickel in the rhizosphere was more than bulk soil Also the results of the plants analysis showed that greenmanure reduced the root yield and increased the shoot yield Yield in mixed culture was more than single culture Phytoextraction of zinc and nickel using intercropping corn and canola and single culture of canola was more thansingle culture of corn While the phytoextraction of copper in corn mixed and single culture was more than canola Green manure increased the phytoextraction of zinc but decreased the phytoextraction of copper Therefore themixed and single culture has differential effects on soil chemical properties and distribution of heavy metals indifferent geochemical fractions Using corn and canola for remediation of heavy metals from contaminated soilswere useful Mixed culture and use of green manure was effective to remediation of soils Keywords Bioavailibility Rhizibox Sequential extraction Mixed culture Canola Lead Zinc

عظيم زاده، ياسر

بررسي اثرات كودسبز، كشت مخلوط و ريز و سفر گياهان ذرت و كلزا بر جزء بندي شيميايي و گياه پالايي سرب و روي در يك خاك آلوده

زيست فراهمي , رايزوباكس , عصاره گيري متوالي ,