Earth, Energy & Environment
Received: 17 Sep 2018 , Published: 22 September 2018
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|1||Win Mi Htwe|
A pot experiment was conducted to evaluate the effects of EDTA and citric acid on the uptake of lead by using high biomass plants (Brachiaria decumbens; signalgrass and Paspalum atratum; atratum). Application levels (0, 1.5, 2.5, 5 and 10 mmol kg–1 soil) of EDTA and citric acid were added to 150 mg kg–1 of lead contaminated soil one week before harvesting. The experimental period was 45 days. The results showed that signalgrass was able to grow in the presence of EDTA and citric acid showing no visible symptoms of phytotoxicity and could have the ability of metal tolerance. EDTA (1.5, 2.5 and 5 mmol kg–1) treated soil significantly increased the concentrations of lead in the shoots of signalgrass by 1.4, 1.5 and 1.3-fold, respectively, in comparison with the control and were clearly more effective in stimulating the translocation of lead from roots to shoots. In atratum, the control plants were more efficient in the uptake and translocation of lead than when EDTA and citric acid were added. Two investigated grass species did not show the same results to the applied chelates. It is imperative to note that the plant species, chelator source and level will make a difference in uptake and translocation of lead. Both EDTA and citric acid were ineffective as an amendment to enhance the lead phytoextraction by atratum. Signalgrass showed comparative high dry matter while accumulating high concentrations of lead in their shoots and then could be suggested as a suitable candidate for chelate-induced phytoextraction of lead.
Alkorta I, Hernández-Allica J, Becerril JM, Amezaga I, Albizu I, Garbisu C (2004) Recent findings on the phytoremediation of soils contaminated with environmentally toxic heavy metals and metalloids such as zinc, cadmium, lead, and arsenic. Rev Environ Sci Biotechnol 3: 71–90.
Athalye VV, Ramachandran V, D’Souza TJ (1995) Influence of chelating agents on plant uptake of 51Cr, 210Pb and 210Po. Environ Pollut 89: 47–53.
Baker AJM, McGrath SP, Sidoli CMD, Reeves RD (1994) The possibility of in situ heavy metal decontamination of polluted soils using crops of metal-accumulating plants. Resour Conserv Recycl 11: 41–49.
Blaylock MJ, Salt DE, Dushenkov S, Zakharova O, Gussman C, Kapulnik Y, Ensley BD, Raskin I (1997) Enhanced accumulation of Pb in Indian mustard by soil-applied chelating agents. Environ Sci Technol 31: 860–865.
Chen YX, Li XD, Shen ZG (2004) Leaching and uptake of heavy metals by ten different species of plants during an EDTA-assisted phytoextraction process. Chemosphere 57: 187–196.
Chen YX, Lin Q, Luo YM, He YF, Zhen SJ, Yu YL, Tian GM, Wong MH (2003) The role of citric acid on the phytoremediation of heavy metal contaminated soil. Chemosphere 50: 807–811.
Clemens S, Palmgren MG, Krämer U (2002) A long way ahead: Understanding and engineering plant metal accumulation. Trends Plant Sci 7: 309–315.
Cunningham SD, Berti WR (2000) Phytoextraction and phytostabilization: technical economic, and regulatory considerations of the soil-lead issue. In: Phytoremediation of contaminated soil and water (Eds Terry N, Bañuelos G), CRC Press, Boca Raton, Florida, 359–376.
Cunningham SD, Ow DW (1996) Promises and prospects of phytoremediation. Plant Physiol 110: 715–719.
Ebbs SD, Kochian LV (1998) Phytoextraction of zinc by oat (Avena sativa), barley (Hordeum vulgare), and Indian mustard (Brassica juncea). Environ Sci Technol 32: 802–806.
Epstein AL, Gussman CD, Blaylock MJ, Yermiyahu U, Huang JW, Kapulnik Y, Orser CS (1999) EDTA and Pb-EDTA accumulation in Brassica juncea grown in Pb-amended soil. Plant Soil 208: 87–94.
Evangelou MWH, Ebel M, Schaeffer A (2006) Evaluation of the effect of small organic acids on phytoextraction of Cu and Pb from soil with tobacco Nicotiana tabacum. Chemosphere 63: 996–1004.
Huang JW, Blaylock MJ, Kapulnik Y (1998) Phytoremediation of uranium-contaminated soils: Role of organic acids in triggering uranium hyperaccumulation by plants. Environ Sci Technol 32: 2004–2008.
Huang JW, Chen J, Berti WR, Cunningham SD (1997) Phytoremediation of lead-contaminated soils: role of synthetic chelates in lead phytoextraction. Environ Sci Technol 31: 800–805.
Kos B, Lestan D (2004) Chelator induced phytoextraction and in situ soil washing of Cu. Environ Pollut 132: 333–339.
Kumar PBAN, Dushenkov V, Motto H, Raskin I (1995) Phytoextraction: the use of plants to remove heavy metals from soils. Environ Sci Technol 29: 1232–1238.
Lombi E, Zhao FJ, Dunham SJ, McGrath SP (2001) Phytoremediation of heavy-metal contaminated soils: natural hyperaccumulation versus chemically enhanced phytoextraction. J Environ Qual 30: 1919–1926.
Luo C, Shen Z, Li X (2005) Enhanced phytoextraction of Cu, Pb, Zn and Cd with EDTA and EDDS. Chemosphere 59: 1–11.
McBride MB (1994) Environmental Chemistry in Soils. Oxford University Press, New York, USA, 1–416.
Nascimento CWA, Xing B (2006) Phytoextraction: a review on enhanced metal availability and plant accumulation. Scientia Agricola 63: 299–311.
Piechalak A, Tomaszewska B, Barakiewicz D (2003) Enhancing phytoremediative ability of Pisum sativum by EDTA application. Phytochem 64: 1239–1251.
Raskin I, Kumar PBAN, Dushenkov S, Salt DE (1994) Bioconcentration of heavy metals by plants. Curr Opin Biotechnol 5: 285–290.
Salt DE, Blaylock M, Kumar PBAN, Dushenkov V, Ensley BD, Chet I, Raskin I (1995) Phytoremediation: A novel strategy for the removal of toxic metals from the environment using plants. Biotech 13: 468–475.
Santos FS, Hernández-Allica J, Becerril JM, Amaral-Sobrinho N, Mazur N, Garbisu C (2006) Chelate-induced phytoextraction of metal polluted soils with Brachiaria decumbens. Chemosphere 65: 43–50.
Shen ZG, Li XD, Wang CC, Chen HM, Chua H (2002) Lead phytoextraction from contaminated soil with high-biomass plant species. J Environ Qual 31: 1893–1900.
Turgut C, Pepe MK, Cutright TJ (2004) The effect of EDTA and citric acid on phytoremediation of Cd, Cr, and Ni from soil using Helianthus annuus. Environ Pollut 131: 147–154.
Vassil AD, Kapulnik Y, Raskin I, Salt DE (1998) The role of EDTA in lead transport and accumulation by Indian mustard. Plant Physiol 117: 447–45.
Wu J, Hsu FC, Cunningham SD (1999) Chelate-assisted Pb phytoextraction: Pb availability, uptake and translocation constraints. Environ Sci Technol 33: 1898–1904.
Wu LH, Luo YM, Xing XR, Christie P (2004) EDTA-enhanced phytoremediation of heavy metal contaminated soil with Indian mustard and associated potential leaching risk. Agri Eco Environ 102: 307–318.
Xu Y, Yamaji N, Shen R, Ma J (2007) Sorghum roots are inefficient in uptake of EDTA-chelated lead. Ann Bot 99: 869–875.