4645

4373

كارشناسي ارشد

خاكشناسي

اصفهان، دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1387

يازده،89،[II]ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

حسين خادمي،مجيد افيوني

مهران شيرواني،قدرت الله سعيدي

5/7/88

محمدعلي حاج عباسي، نورالله مير غفاري

مهندسي كشاورزي

ID4373

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

Potential of Clay Deposits Containing Smectite andPalygorskite to Perevent Cadmium from Entering Canola and Maize Tahereh Sadat Taleghani tahereh taleghani@yahoo com 2009 3 9 Department of Soil Science Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiDr H Khademi hkhademi@cc iut ac irDr M Afyuni afyuni@cc iut ac irrAbstractSoil contamination by heavy metals such as cadmium lead chromium zinc mercury and arsenic is aworldwide concern The presence of heavy metals in the environment is a major threat to water and soilquality due to their high toxicity to plants animals and human Minimizing the production of hazardousheavy metals has become one of the most important environmental challenges that the world faces today Several treatment technologies have been developed for eliminating heavy metals from solutions Amongthese methods the adsorption and ion exchange using natural absorbents have received a great attention Clay minerals are considered good absorbents for heavy metals due to their low cost high abundance easymanipulation and harmlessness to the environment The objectives of this study were to investigate thepotential of clay deposits containing smectites and palygorskite to absorb cadmium and to reduce itsmovement into canola and maize Two selected deposits are located in the Isfahan province Physical andchemical characteristics of clay deposits were determined The clay fraction was then separated from eachdeposit sample XRD analyses msubmicroscopic investigations and adsorption isotherm studies werecarried out on the clay fraction of both samples These clays were then used as an amendment to plantgrowth medium X ray diffraction analyses and electron microscope studies SEM and TEM showed thatpalygorskite is the dominant clay mineral in deposit sample no 1 and smectites in deposit sample no 2 Both SEM and TEM micrographs of sample 1 indicated the presence of elongated and fibrous shapedpalgorskite bundles They also showed clearly the irregular plate like particles of smectites The adsorptionisotherms showed that smectite and palygorskite absorbed cadmium in low and medium concentration Theadsorption data of cadmium fit the Langmuir equation isotherm reasonably well but not as well asFreundlich Pot examination result s indicated that smectite and palygorskite very useful in removingcadmium from pollution soils The unique properties of palygorskite and smectite prepare their forenvironmental applications In landfills and toxic soils a mixture of palygorskite and smectite works wellto prevent movements of heavy metal and toxic pollutants and their absorbs These clays approached tomaximum self power But 2 deposit s for the reason that having high per cent of smectite as compared with1 deposit s could to prevented at greatly rate from entrance Cd into plants smectites have very differentproperties than palygorskite The high layer charge the very fine particle size the thin flakes the highcation exchange capacity and the high surface area are more important properties of smectite Canola andmaize planted in pots content smectite to be come well from growing Cadmium association in plants rootwas more than shoot Also increase cadmium concentration in plant bed effected to increased of Cd uptake Key Words clay deposits smectite palygorskite cadmium canola maize

حسين خادمي،مجيد افيوني

مهران شيرواني،قدرت الله سعيدي

محمدعلي حاج عباسي، نورالله مير غفاري