Lead phytoextraction from contaminated soil with high-biomass plant species.
ABSTRACT In this study, cabbage [Brassica rapa L. subsp. chinensis (L.) Hanelt cv. Xinza No 1], mung bean [Vigna radiata (L.) R. Wilczek var. radiata cv. VC-3762], and wheat (Triticum aestivum L. cv. Altas 66) were grown in Pb-contaminated soils. Application of ethylenediaminetetraacetic acid (EDTA) (3.0 mmol of EDTA/kg soil) to the soil significantly increased the concentrations of Pb in the shoots and roots of all the plants. Lead concentrations in the cabbage shoots reached 5010 and 4620 mg/kg dry matter on Days 7 and 14 after EDTA application, respectively. EDTA was the best in solubilizing soil-bound Pb and enhancing Pb accumulation in the cabbage shoots among various chelates (EDTA, diethylenetriaminepentaacetic acid [DTPA], hydroxyethylenediaminetriacetic acid [HEDTA], nitrilotriacetic acid [NTA], and citric acid). Results of the sequential chemical extraction of soil samples showed that the Pb concentrations in the carbonate-specifically adsorbed and Fe-Mn oxide phases were significantly decreased after EDTA treatment. The results indicated that EDTA solubilized Pb mainly from these two phases in the soil. The relative efficiency of EDTA enhancing Pb accumulation in shoots (defined as the ratio of shoot Pb concentration to EDTA concentration applied) was highest when 1.5 or 3.0 mmol EDTA/kg soil was used. Application of EDTA in three separate doses was most effective in enhancing the accumulation of Pb in cabbage shoots and decreased mobility of Pb in soil compared with one- and two-dose application methods. This approach could help to minimize the amount of chelate applied in the field and to reduce the potential risk of soluble Pb movement into ground water.
SourceAvailable from: Int. J. Chem. Mater. Environ. Res. (ISSN 2410-5945)[Show abstract] [Hide abstract]
ABSTRACT: The levels of lead (Pb) in soils (S), and eight (8) plants (P) growing naturally in a main agricultural activity, semi-arid zone and where there has been a long-term activity of heavy machineries carrying out construction works in the area were de-termined using atomic absorption spectrophotometer (AAS). Their concentration factors (CF) were also calculated. Whole plant parts were used, these include: calotropis procera (P = 4.6012 µg/g, S = 4.8611µg/g, CF = 0.9465). Commelina sp (P = 1.7053 µg/g, S = 1.479 µg/g, CF = 1.153), Colocynthis bulgaris (P = 1.4971 µg/g, S = 1.4231 µg/g, CF = 1.052), cucur-bita pepo (P = 1.754 µg/g, S = 1.342 µg/g, CF = 1.307), haemanthus sp (P = 0.1645 µg/g, S = 0.0164 µg/g, CF = 1 0.03), hibiscus esculenta (P = 0.5357 µg/g, S=0.1759 µg/g, CF = 3.045), mitracarpus scaber (P = 0.3313 µg/g, S=0.85 µg/g, CF = 0.3898) and lactuca taraxacifolia (P = 4.1067 µg/g, S = 4.8913 µg/g, CF = 1.63). The study is important considering the harmful effects of Pb in human and animal physiological systems. Results were significant at 0.05 level.
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ABSTRACT: Application of waste water for irrigation purposes has increased over the past years. This waste water contains high amounts of trace elements and heavy metals.Many of these are non-essential and toxic to plants, animals and human beings. The use of polluted water in the immediate surroundings of big cities in Pakistan is a common practice for growing of vegetables. When this water applied for long time in irrigation, these heavy metals may accumulate in soil and that may be toxic to plants and also cause deterioration of soil. The present study revealed that heavy metal content was above the toxicity level in leafy vegetables grown in the area of Lahore. This study showed that among the different tested plant species, the amount of heavy metals was more in leaves than fruits. Plants whose fruits grow below the soil showed higher concentration of heavy metals while other showed less concentration whose edible portion was above the ground level. Leafy vegetables (spinach, cabbage, coriander etc) showed higher concentration in leaves than in fruits. The concentration of heavy metals in upper layer of soil (0 -15 cm) is higher than the lower layer (15-30 cm). The reason behind is that the upper layer was receiving sewage water permanently while the penetration of sewage water below 15 cm was less. The increase in heavy metal accumulation in different plant species and their different parts is not constant and is not in proportion to the increase in heavy metal concentration in soil irrigated with sewage wastewater.Journal of microbiology, biotechnology and food sciences 04/2015; 4(5):387-392. DOI:10.15414/jmbfs.2015.4.5.387-392
Dataset: Removal of Lead.