ENRICHMENT AND KINETICS OF BIODEGRADATION OF 1-NAPHTHYLAMINE IN ACTIVATED-SLUDGE

Sequencing-batch reactors were used to develop an activated sludge enr ichment culture capable of degrading 1-naphthylamine (1NA). Approximat ely 5 months acclimation with salicylic acid (1 600 mg l-1) as the pri mary source of carbon were required to obtain an enrichment culture ab le to degrade even small quantities of 1NA. After an additional 4 mont hs acclimation, during which the concentration of salicyclic acid was decreased to 50 mg l-1, a culture developed that degraded 1NA concentr ations as high as 300 mg l-1. Kinetic determinations showed that 1NA d egradation (in the presence of salicylate) followed Michaelis-Menten k inetics with K(m) and V(m) values of 32.5 +/-2.2 mg l-1 and 375 +/- 18 ng 1 NA mg-1 cells h-1, respectively. The same enrichement was able t o degrade 1NA when present as the sole source of carbon and energy and to convert approximately 87% to CO2.