(a) Constructed anaerobic cycle for the biotransformation of 2,4,6-TNT to 2,4,6-TAT with anaerobic sludge. (b) The subsequent transformations of 2,4,6-TAT to the corresponding azo derivatives at pH 7.0 and to the corresponding phenolic compounds at pH 2 to 3. Dashed arrows indicate that THT was formed in trace amounts at best, and its formation required heating in water at 100°C.