Lead Phytoextraction from Contaminated Soil with High-Biomass Plant Species

ArticleinJournal of Environmental Quality 31(6):1893-900 · November 2002with72 Reads
DOI: 10.2134/jeq2002.1893 · Source: PubMed
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.
    • "Energy crops fall into two categories: annuals: sweet sorghum and fiber sorghum, kenaf, and rapeseed ; and perennials, a category further subdivided into (a) agricultural: wheat, sugar beet, cardoon, reeds, miscanthus, switchgrass, and canary reed grass; and (b) forest: willows, poplars, eucalyptus, and black locust (Simpson et al., 2009). High biomass crops with HM tolerance such as Indian mustard, oat, maize, barley, sunflower, ryegrass, fast-growing willow, and poplars have been studied (Komárek et al., 2007; Meers et al., 2005; Shen et al., 2002; Vervaeke et al., 2003). Table 2summarizes the HM removal efficiency of several agricultural crops (Zhuang et al., 2009). "
    [Show abstract] [Hide abstract] ABSTRACT: The practice of phytoremediation is suggested for lands contaminated with heavy metals (HMs) as it helps to preserve natural physical and biological properties of soil. Sweet sorghum is a C4 crop valued for food, feed, fodder, fiber, and fuel. Its characteristics of rapid growth, higher biomass potential, wider adaptability to harsh agroclimatic conditions, along with its metal-absorbing property, are propelling the use of this novel feedstock in phytoremediation also. Currently, many developing countries are switching from the cultivation of traditional biofuel crops like sugarcane, corn, sugar beet, sweet potato, cassava, etc., to sweet sorghum in order to reduce gasoline imports/use. A wide range of plant growth-promoting (PGP) microbes such as Rhizobium, Pseudomonas, and Bacillus are reported not only to enhance the plant growth but also to alleviate the stress caused by HMs in plant. This chapter explores the possibilities of using sweet sorghum with PGP microbes as a phytoremediation tool to alleviate the HM stress and to enhance food-fodder-fuel security.
    Chapter · Dec 2016 · International Journal of ChemTech Research
    • "Exposure to lead (Pb), for example, is recognized as a major risk factor for several human diseases, and the structure of industrial ecological systems have made exposure to Pb unavoidable for most people alive today ([4],[5]). The removal of these toxic metals and contaminants from industrial wastewater is a matter of great interest in the field of water pollution, which is a serious cause of water degradation ([6],[7],[8]) A wide range of wastewater treatment techniques having some associated advantages and disadvantages are prevailing [2]. Most commonly wastewater treatments involve biological treatment such as nitrification, denitrification and phosphorus removal, physio-chemical treatment such as adsorption ([9], [10]), ion exchange [11], precipitation [12], reverse osmosis [13], coagulation, and electrocoagulation [14]. "
    [Show abstract] [Hide abstract] ABSTRACT: In this study, the effectiveness of tamarind seed powder as a coagulant for treating detergent wastewater using coagulation-flocculation process has been evaluated by varying pH, mixing time and coagulant dosage, which were the selected operating parameters for the treatment process. The coagulant was prepared by drying, crushing and grinding the tamarind seeds to form medium fine powder. A conventional jar test apparatus was used to carry out the coagulation-flocculation of the sample of wastewater using the tamarind seed powder. The optimum pH of the process was found to be 7.25 with turbidity and COD removal of 97.01% and24.86% respectively;the optimum mixing time was obtained to be 3 minutes of rapid mixing and 15 minutes of slow mixing with turbidity and COD removal of 97.78% and43.50% respectively while the optimum dosage was given to be 400 mg/L with turbidity and COD removal of 97.72% and 39.55% respectively. The kinetics of the coagulation-flocculation process was found to be obey the first order rate expression, the rate constant of which was estimated to be 0.044/min. The fitting of the rate equation to the kinetics data gave square of the correlation coefficient (R-squared) of 0.9983, which was an indication that the data was represented by the model very well. In conclusion, tamarind seed has been found to be effective in treating detergent industry wastewater. It is, therefore, recommended that local industries should consider using this material for wastewater treatment as an alternative to chemical coagulants because it is biological, cheap and readily available.
    Full-text · Article · Jun 2016
    • "O) onfaba bean plants grown in sandy Althoughheavymetalsarenaturallypresentinthesoil,geologicandanthropogenicactivitiesincrea setheconcentrationoftheseelementstoamountsthatareharmfultobothplantsandanimals. Someofthes eactivitiesincludeminingandsmeltingofmetals, burningoffossilfuels,useoffertilizersandpesticidesinagri culture,productionofbatteriesandothermetalproductsinindustries,sewagesludge, andmunicipalwaste disposal (Alloway et al.,1990; Raskin et al.,1994 and Shen et al.,2002). Growth reduction as a result of changes in physiological and biochemical processes in plants growing on heavy metal polluted soils has been recorded (Chatterjee and Chatterjee, 2000 and Oncel et al., 2000). "
    Full-text · Article · Mar 2016 · International Journal of ChemTech Research
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