title: Potential of activated carbon to decrease 2,4,6-trinitrotoluene toxicity and accelerate soil decontamination.
abstract: Activated carbon can be used to decrease 2,4,6-trinitrotoluene (TNT) toxicity and promote bioremediation of highly contaminated soil. Adding activated carbon at 0.25, 0.75, and 1.0% (w/w) to Sharpsburg soil contaminated with 500, 1,000, and 2,000 mg TNT/kg decreased concentrations of TNT and its transformation products in soil solution to 5 mg/L or less, resulting in low toxicity to corn plants (Zea mays L.) and soil microorganisms. As much as 50% of the added TNT was rapidly bound to the soil-activated carbon matrix. Simultaneous accumulation of 2,4,6-trinitrobenzaldehyde (TNBAld) indicated that the activated carbon promoted oxidation of TNT. Some of the TNBAld was further oxidized to 1,3,5-trinitrobenzene, followed by reduction to 3,5-dinitroaniline. Reversibly bound TNT was gradually transformed to 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene, and both were bound to the soil-activated carbon matrix. The transformation and binding of TNT to soil were further promoted by incorporating shredded corn plants after growing for 52 d in the activated carbon-amended soil. After 120 d, these amendments reduced extractable TNT and transformation products by 91% in soil containing 2,000 mg TNT/kg, compared to 55% in unamended soil. These results demonstrate the potential use of activated carbon in combination with plants to promote in situ bioremediation of soils highly contaminated with explosives.
authors.affiliation: School of Natural Resource Sciences, University of Nebraska, Lincoln, Nebraska 68583-0758, USA.
authors.forename: G K
authors.initials: GK
authors.lastname: Vasilyeva
authors.forename: V D
authors.initials: VD
authors.lastname: Kreslavski
authors.forename: B T
authors.initials: BT
authors.lastname: Oh
authors.forename: P J
authors.initials: PJ
authors.lastname: Shea
mesh_terms: D002244:Carbon / Q000494:pharmacology*; D010944:Plants / Q000187:drug effects; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*; D014303:Trinitrotoluene / Q000633:toxicity*
chemical_list: D012989:Soil Pollutants; D014303:Trinitrotoluene; D002244:Carbon