Environmental Fate
Biological. A mixed culture of soil bacteria or a Pseudomonas sp. transformed 1,2,3,4-
tetrachlorobenzene to 2,3,4,5-tetrachlorophenol (Ballschiter and Scholz, 1980). After incubation in
sewage sludge for 32 d under anaerobic conditions, 1,2,3,4-tetrachlorobenzene did not biodegrade
(Kirk et al., 1989). The half-life of 1,2,3,4-tetrachlorobenzene in an anaerobic enrichment culture
was 26.4 h (Beurskens et al., 1993). Potrawfke et al. (1998) reported that a pure culture of
Pseudomonas chlororaphis RW71 mineralized 1,2,3,4-tetrachlorobenzene as a sole source of
carbon and energy. Intermediate biodegradation products identified were tetrachlorocatechol,
tetrachloromuconic acid, 2,3,5-trichlorodienelactone, 2,3,5-trichloro-4-hydroxymuconic acid.
In an enrichment culture derived from a contaminated site in Bayou d’Inde, LA, 1,2,4,5-
tetrachlorobenzene underwent reductive dechlorination yielding 1,2,4-trichlorobenzene. The
maximum dechlorination rate, based on the recommended Michaelis-Menten model, was 208
nM/d (Pavlostathis and Prytula, 2000).
Photolytic. Irradiation (λ ≥285 nm) of 1,2,3,4-tetrachlorobenzene (1.1–1.2 mM/L) in an
acetonitrile-water mixture containing acetone (0.553 mM/L) as a sensitizer gave the following
products (% yield): 1,2,3-trichlorobenzene (9.2), 1,2,4-trichlorobenzene (32.6), 1,3-dichlorobenzene
(5.2), 1,4-dichlorobenzene (1.5), 2,2′,3,3′,4,4′,5-heptachlorobiphenyl (2.52), 2,2′,3,3′,4,5,6′-
heptachlorobiphenyl (1.22), 10 hexachlorobiphenyls (3.50), five pentachlorobiphenyls (0.87),
dichlorophenyl cyanide, two trichloroacetophenones, trichlorocyanophenol, (trichlorophenyl)
acetonitriles, and 1-(trichlorophenyl)-2-propanone (Choudhry and Hutzinger, 1984). Without
acetone, the identified photolysis products (% yield) included 1,2,3-trichlorobenzene (7.8), 1,2,4-
trichlorobenzene (26.8), 1,2-dichlorobenzene (0.5), 1,3-dichlorobenzene (0.7), 1,4-dichloro-benzene
(30.4), 1,2,3,5-tetrachlorobenzene (2.26), 1,2,4,5-tetrachlorobenzene (0.72), 2,2′,3,3′,4,4′,5-
heptachlorobiphenyl (<0.01), and 2,2′,3,3′,4,5,6′-heptachlorobiphenyl (<0.01) (Choudhry and
Hutzinger, 1984). The sunlight irradiation of 1,2,3,4-tetrachlorobenzene (20 g) in a 100-mL
borosilicate glass-stoppered Erlenmeyer flask for 56 d yielded 4,280 ppm heptachlorobiphenyl
(Uyeta et al., 1976).
