The biodegradation of high concentration of benzoate by enrichment culture with Pseudomonas sp. was investigated. During 50 days continuous culture, average of removal rate of benzoate and COD were 90% and 83%, respectively. And the enzymatic activity of catechal 2,3-dioxygenase was determined in the continuous culture but not Catechol 1,2-dioxygenase. On the other hand, Pseudomonas sp in the culture was investigated with SEM and the result was revealed that the cell shape was more demage according the higher concentration of benzoate.

Optimal biodegradation kinetics models to the initial nonylphenol ethoxylates-30 concentration were investigated and had been fitted by the linear regression. Microorganisms capable of degrading nonylphenol ethoxylates-30 were isolated from sewage near Ulsan plant area by enrichment culture technique. Among them, the strain designated as EL-10K had the highest biodegradability and was identified as Pseudomonas from results of taxonomical studies. The optimal conditions for the biodegradation were 1.0 g/l of nonylphenol ethoxylates-30 and 0.02 g/l of ammonium nitrate at pH 7.0 and 30℃. The highest degradation rate of nonylphenol ethoxylates-30 was about 89% for 30 hours incubation on the optimal condition. Biodegradation date were fit by linear regression to equations for 3 kinetic models. The kinetics of biodegradation of nonylphenol ethoxylates was best described by first order model for 0.1 ㎍/l nonylphenol ethoxylates-30 ; by Monod no growth model and Monod with growth model for 0.5 ㎍/ml and 1.0, 5.0 ㎍/ml, respectively.

In order to find the most fitted biodegradation model, biodegradation models to the initial 4-chlorophenol concentrations were investigated and had been fitted by the linear regression. The degrading bacterium, EL-091S, was selected among phenol-degraders. The strain was identified with Pseudomonas sp. from the result of taxonomical studies. The optimal condition for the biodegradation was as fellows: secondary carbon source, concentration of ammonium nitrate, temperature and pH were 200㎎/l fructose, 600 ㎎/l, 30℃ and 7.0 respectively. The highest degradation rate of the 4-chlorophenol was about 58% for 24 hours incubation on the optimal condition. Biodegradation kinetics model of 5 ㎎/l 4-Chlorophenol, 10 ㎎/l 4-chlorophenol and 50 ㎎/l 4-chlorophenol were fitted the zero order kinetics model, respectively.