BIODEGRADATION OF TOLUENE DIAMINE (TDA) IN ACTIVATED-SLUDGE ACCLIMATED WITH ANILINE AND TDA

The biodegradability of toluene diamine (TDA) which has been regarded as a ''recalcitrant compound'' was examined in activated sludges. In t his study, a microorganic-enzyme system which metabolized TDA was obta ined by acclimating the activated sludge with aniline and TDA. In the sludge subject to be 200 days' acclimation, the considerable increase in respiration rate with the addition of TDA, accompanied the sharp de crease in its concentration. This indicated that TDA was metabolized f ortuitously. The rate of biodegradation of TDA in the absence of anili ne was first order with respect to its concentration when the initial TDA concentration was less than about 5 mg/l. The rate constant in thi s relation was proportional to mixed liquor suspended solid (MLSS). Ho wever, when the initial TDA concentration exceeded 5 mg/l, the plots w ere deviated from a first order rate equation.