Dl. Freedman et al., AEROBIC BIODEGRADATION OF 2,4-DINITROTOLUENE, AMINONITROTOLUENE ISOMERS, AND 2,4-DIAMINOTOLUENE, Journal of hazardous materials, 49(1), 1996, pp. 1-14
2,4-Dinitrotoluene (DNT) is widely used in industry, including the man
ufacture of propellants. 2,4-Diaminotoluene (DAT), 2-amino-4-nitrotolu
ene (2A4NT), and 4-amino-2-nitrotoluene (4A2NT) are among the products
that can result from biological treatment of DNT. The objective of th
is study was to examine the biodegradability of these hazardous compou
nds. Using an inoculum from a munitions wastewater treatment plant, en
richment cultures were developed that readily consumed DAT, 4A2NT, 2A4
NT, and DNT when they were provided as sole organic substrates (84-100
mg 1(-1)) or when ethanol (600 mg 1(-1)) was added as a cosubstrate.
Low effluent chemical oxygen demand (COD) levels suggested that the ar
omatics were mineralized, rather than simply transformed to other poss
ibly hazardous compounds. The addition of ether (142 mg 1(-1)) as a co
substrate had no significant effect on the biodegradation of DAT and 4
A2NT, but did inhibit the consumption of DNT and 2A4NT. The presence o
f ether in munitions wastewater may therefore present a challenge to e
ffective biological treatment. When DNT was added to enrichment cultur
es as sole substrate, nitrite was released stoichiometrically. However
, when ethanol was also added, nitrite release was only 59% of the max
imum, indicating that most of the DNT was reduced prior to ring cleava
ge. When provided to enrichment cultures as the sole substrates, the o
bserved yield coefficients for the aromatic compounds ranged from 0.10
to 0.28 mg of volatile suspended solids per mg COD.