＜Biological treatment of red water effluent discharged in the production of TNT＞
2,4,6-trinitrotoluene (TNT), widely used as the main ingredient in mines, artillery shells, and other explosives, is produced by two-step nitration of o-nitrotoluene. However, unreacted dinitrotoluene and trinitrotoluene isomers are also produced in the process. Therefore, TNT is purified by the Celite method using sodium sulfite solution, which is the most common method. In the Celite method, the reactive nitro groups of the asymmetric TNT are easily removed by substitution with sodium sulfonate to form water-soluble sulfonates. The dinitrotoluenesulfonate solution has a characteristic red color, which is discharged with the production of TNT as red water effluent, and various treatment methods are being investigated.
Red water wastewater has been treated by incineration, but this is not always the best method considering the environmental impact. Therefore, this laboratory is working on biological treatment as a new treatment method for red water effluent in collaboration with Chugoku Kayaku Co. Currently, we are studying the treatment of red water using Pseudomonas sp. strain TM15, which is capable of biodegrading TNT, and the treatment of red water by acclimation culture using sludge.
