Showing 3 results for Edta
E Fatahi Kiasari , A Fotovvat, A.r Astaraei , Gh Haghnia ,
Volume 14, Issue 51 (4-2010)
Abstract
The contamination of soils with lead is a major environmental problem throughout the world. Phytoextraction of heavy metals from contaminated soils has the prospect of being a more economic in situ alternative. Chemically enhanced phytoextraction has been proposed as an effective approach to remove heavy metals from contaminated soil through the use of high biomass plants. Using a pot experiment, the effects of the application of three rates of EDTA at 0, 1.5 and 3 mmol/kg soil and sulfuric acid at 0, 0.5 and 1 mmol/kg soil with two rates of Pb at 0 and 200 mmol.kg-1 on the uptake of Pb by corn (Zea mays L. single cross 704 var.), sunflower (Helianthus annuus L. ajili var.), and cotton (Gossypium hirsutum L. varamin var.) plants were studied. The results showed that EDTA was more effective than sulfuric acid in increasing the concentration of Pb in shoots and roots for all plants studied. The maximum amount with application of EDTA to soil for shoots of corn, sunflower, and cotton were 4.07, 6.49 and 31.33 times higher than the control, respectively. EDTA also enhanced Pb content of roots of corn, sunflower, and cotton 3.38, 1.63 and 1.09 times higher than the control, respectively. DTPA-Pb was higher in soil treated with EDTA than sulfuric acid. The application of EDTA also significantly increased shoot-to-root ratio of Pb in plants examined. The results of this study showed that corn was able to phytoextract more Pb than sunflower and cotton.
M. Esfahani Moghaddam, A. Fotovat, Gh. Haghnia,
Volume 16, Issue 59 (4-2012)
Abstract
Silver toxicity and its fate in the environment are currently being debated and are important as challenging research topics. Even though there are several studies on its total content in soils, fractionation of Ag especially in calcareous soils has not been investigated. Therefore, to provide fundamental information on the chemical behavior of Ag in calcareous and noncalcareous soils, we studied 8-step chemical fractions of Ag (i.e., EXCH, CARB, Me-Org, re-MeOx, H2O2-Org, am-MeOx, cr-FeOx, and RES) after 30 and 60 days of incubation in soils amended with Ag (0 and 15 mg kg-1), sewage sludge (0 and 20 t ha-1) and EDTA (0 and 0.5%). Experimental results showed that redistribution of Ag in spiked noncalcareous soils was EXCH (34%), H2O2-Org (33%) and RES (17%). In calcareous soils, after 30 days, EXCH- and RES-Ag increased but at the end of 60 days H2O2-Org-Ag increased. Based on our data, we could conclude that addition of Ag results in an increase of Ag mobility in soils but incubation and sewage sludge may have adverse effect on its mobility. In contrast to noncalcareous soil, EDTA in calcareous soil resulted in higher Ag mobility. This may have environmental implications in Ag polluted calcareous soils.
M. Ebrahimi, M. Jafari, E. Rouhimoghaddam,
Volume 19, Issue 72 (8-2015)
Abstract
The present study was conducted to increase phytoextraction efficiency of Festuca ovina L. in lead contaminated soil in the EDTA-assisted (0, 1.5, 3, 1.5+1.5, 3+3, 6 mmol kg−1), assess the best time of plant harvesting to increase Pb uptake and method of EDTA application to reduce Pb leaching risk. The results revealed that the greatest Pb uptake was observed in 3EDTA treatment. Therefore, 3mmolkg-1 was used in the second step for assessing harvest time for 15, 30 and 45 days. Results showed that the concentration of Pb in plant tissues was increased with the passage of time and the best harvest time to achieve maximum removal of Pb was 60 days of the first harvest. In the third step to reduce leaching of Pb-chelate, 3mmolkg-1 EDTA in five ways of single, double, triple, quadruplet, quintuplet were added to the soil. The results indicated that under quintuplet application, Pb content reached its minimum concentration in the soil and in the plant organs, the Pb concentration was maximum and metal concentration in the plant organs did not vary significantly when triple, quadruplet and quintuplet dosages were added (p<5%). Overall, optimum phytoextraction of F. ovina L. and Pb leaching reduction were achieved when 3mmol kg−1 EDTA was added in quintuplet dosage and the plant was harvested at the end of growth stage.
