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چكيده انگليسي :

۵ Effect of Wastewater Pumice and Zeolite on Cadmium Uptake by Spinach Spinacia Oleares L Razieh Mollaei Razieh mollaei@yahoo com February 2012 02 19 Department of Water Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiDr Abedi Koupai Supervisor Koupai@cc iut ac irDr Eslamian Supervisor saeid@cc iut ac irAbstractHeavy metal toxicity is one of the major current environmental health problems and it is potentially for humanconsumption dangerous due to bioaccumulation through the food chain and in plant products A growingdemand for irrigation water has produced a marked increase in the reuse of treated and or untreated industrialand municipal wastewater worldwide Heavy metals in wastewater come from industries and municipal sewage and they are one of the main causes of water and soil pollution Among heavy metals cadmium accumulatesmore in plants and by increasing the cadmium level in soil its concentration in plants increases significantly The availability of metal in contaminated soil can be reduced by the addition of soil amendments Theobjectives of this study were to evaluate the application effects of pumice and zeolite as soil amendments on soilDTPA extractable and the uptake of Cd by spinach Spinacia Oleares L grown in three different conditions 1 irrigation with wastewater containing 10 ppm Cd 2 a Cd contaminated soil 25 mg kg soil and 3 irrigation with wastewater containing 10 ppm Cd in Cd contaminated soil 25 mg kg soil In each ofconditions the experiment was conducted as a completely randomized design in a green house with 3replications Different levels of pumice 0 4 and 8 g 100 g soil and zeoilte 0 1 and 5 g 100 g soil were addedto soil The results indicated that the addition of pumice 4 and 8 g 100 g soil and zeolite just 1 g 100 g soil in soil treated with wastewater reduced cadmium concentration in root of spinach But this effect onconcentration of shoot Cd was not significant P 0 05 The percentage of DTPA extractable Cd in soilsamended with pumice 8 and zeolite 1 was decreased significantly and this resulted in lower Cdaccumulation in plant Application of zeolite at 5 level had no significant effect on cadmium concentration inplant but this treatment increased the percentage of soil DTPA extractable Cd and also increased soil salinity Spinach biomass and yield did not differ significantly among the treatments under irrigation by wastewater Butirrigation with wastewater containing Cd caused a decrease in biomass and yield comparison with water Alsosoil salinity increased after irrigation with wastewater Concentration of Cd was higher in shoots than in roots Cadmium transfer factor from soil to plant was found significantly higher in 5 zeolite application and controlthan other treatments Moreover zeolite 5 increased Cd content in shoot significantly P 0 05 In Cd contaminated soil 25 mg kg soil irrigated with water and wastewater zeolite 5 showed maximumconcentration of cadmium in plant and the maximum percentage of soil DTPA extractable Cd that wassignificantly higher than other treatments Other treatments except zeolite 1 increased cadmiumconcentration in plant which did not show significant different with control Zeoilte 5 and pumice 8 hadthe highest cadmium transfer factor from soil to plant The concentration of Cd was higher in roots than inshoots Zeolite and pumice hadn t significant effect on biomass But presence of cadmium was found to reduceit In each of three conditions of this study Cd concentration in plant was positively correlated with thepercentage of soil DTPA extractable Cd Also addition of zeoilite at 1 level was effective in reducing theadsorption of cadmium in plant Keywords Cadmium Heavy metal Pumice Spinach Wastewater Zeolite

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تاثير پساب، پاميس و زئوليت بر جذب كادميم در گياه اسفناج

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