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A Study of the Use of Alfalfa ( Medicago sativa L. ) for the Phytoremediation of Organic Contaminants in Soil
Author(s) -
Chekol Tesema,
Vough Lester R.
Publication year - 2001
Publication title -
remediation journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.762
H-Index - 27
eISSN - 1520-6831
pISSN - 1051-5658
DOI - 10.1002/rem.1017
Subject(s) - pyrene , phytoremediation , organic matter , medicago sativa , environmental chemistry , chemistry , soil water , soil organic matter , soil contamination , agronomy , environmental science , soil science , organic chemistry , biology , heavy metals
Abstract This article presents the results of a study that was conducted to determine the effectiveness of usingalfalfa ( Medicago sativa L. ) to enhance the phytoremediation of three different typesof chemical contaminants. The chemicals studied were trinitrotoluene (TNT), the polycyclic aromatichydrocarbon (PAH) pyrene, and the polychlorinated biphenyl (PCB) Aroclor 1248. Experimentswere conducted using soils that contained high and low organic matter content. The results indicated thatrecoveries of pyrene and TNT from soil were highly dependent on the soil organic matter content, while therecovery of PCB was not. Significantly low levels of pyrene and TNT were recovered from all treatments in thesoil with 6.3 percent organic matter content compared to recovery levels found in soil with 2.6 percent organicmatter. The presence of alfalfa plants had a significant effect on the transformation of TNT and PCB in the loworganic matter content soil only and had no effect on the fate of pyrene. In the low organic matter soil, only15 percent and 17 percent of the initial TNT and PCB levels, respectively, were transformed in the unplantedcontrol soils compared to 66 percent and 77 percent in the alfalfa planted pots. In both soil types, pyrenedissipation could not be attributed to the presence of alfalfa plants. Overall, it was concluded that under highsoil organic matter conditions, adsorption and covalent binding to the soil organic matter appeared to be thedominant force of pyrene and TNT removal. The effectiveness of using alfalfa to enhance PCB and TNTtransformations was more significant in the lower organic matter soil; thus phytoremediation had a greatereffect in soils with lower organic matter content. © 2001 John Wiley & Sons, Inc.