Study On The Degrading-phenol Microorganism And Its Immobilized Cells

Phenol is a kind of commonly industry pollution. It would bring serious influence to human healthy and environment, if phenol were discharged without degradation. Because many microorganisms can use phenol as sole grow carbon source, biodegradation of phenol have been developed for recent twenty years.In this work, six strains of phenol-degrading bacteria were isolated from the polluted sludge. These six strains all have good performance of degrading phenol in wastewater.The strain DP4 was selected as research object. Its performance of degrading phenol and the influence of environmental factors were studied in our work. The optimal grow temperature of the strain DP4 was 30℃, and the optimal grow pH value was pH6-9. The optimal temperature of degrading phenol was 30-35℃, and pH value was pH6-8. At the same time, the sufficient oxygen was necessary for phenol degradation.In the laboratorial situation, provided with the optimal conditions at 30℃,pH7 and 120r·min-1 in the rotary vibrator for about 48hours, when the concentration of phenol were 500mg·L-1,1000mg·L-1,1500mg·L-1 and 2000 mg·L-1,the phenol degrading ratios were 100%,97.1%,74.2% and 56.2% , respectively. Further more, if the six phenol-degrading strains were mixed, the phenol degrading ratio of the mixed strains would be apparently superior to that of the strain DP4. The course of degrading phenol of the strain DP4 was accord with the Monod model. And the two parameters of the Monod model were rs,max=33.6 mg·L-1·h-1 and Km=282.5 mg·L-1。 The immobilized cells of the Degrading-phenol bacteria have better performance of degrading phenol. Optimal preparation condition of the strain immobilization was carried out by the cross-test experiments.The results showed that the degradation efficiency of immobilized cells was apparently superior to that of the free cells, and the optimal temperature of degrading phenol was 30-35℃, the optimal pH value was pH6-8.At the same time, the immobilized cells of the strain DP4 have good performance of degrading COD in wastewater.The study proved that biodegradation of phenol was feasible, and provided theoretical and experimental rudiments for the further science research and industrial application.