Degradation Characteristics Of Phenol Degrading Bacterium JNCP

Environmental pollution has become a bottleneck restricting problem in development of society and economy in China.Phenol is widely monitored in the released waste water of oil refineries or food processing plants,which is defined as a carcinogenic organic chemical substance with high toxicity and stable covalent bond.The research of safe degradation of Phenol has been a hot topic in environmental science field.Rhizobium Ralstonia sp.JNCP and Ralstonia eutropha have a high similarity in evolutionary analysis tree,and the latter has a powerful ability in resistance of metal and degradation of organic pollutants.In this study,Rhizobium JNCP is selected as an object,characteristic and main inhibitory factors of Phenol degradation JNCP was studied via different initial Phenol concentration,pH and carbon source.In addition,the filter of most appropriate cultivated conditions of JNCP were conducted by batch fermentation technology,moreover,the ability of degrading organic pollutants of Ralstonia sp.JNCP was also explored.The main results are as follows:(1)JNCP had a relative high resistance ability of metal,however,it still produce matrix inhibitory effect due to its toxicity,which was consistent with the matrix inhibition phenomenon described by kinetic equation Haldane;Under the Phenol concentration of 200 mg/L,Phenol almost did not produce significant matrix inhibitory effect,and could obtain maximum phenol degradation rate and the shortest period of stagnation of JNCP.Due to matrix inhibitory effect,the Phenol concentration is higher,the stagnation period is longer and Phenol degradation rate is slower.Consequently,the best condition for Phenol degradation rate is that Phenol concentration is controlled less than and equal to 200 mg/L throughout.(2)The results of pH and cultivated carbon source matrix showed that the best range of pH for Phenol degradation by JNCP is 7?8,as pre-cultivated carbon source matrix,acetic acid or sodium acetate is more economical.LB medium is the best culture medium.When the sodium acetate concentration is more than 0.25%,JNCP cell growth rate decreased with increasing of sodium acetate concentration;while the sodium acetate concentration is more than 1%,the cell growth will show a significant matrix inhibition.(3)The statistical analysis showed that the best degradation condition for Phenol degradation bacteria JNCP is:Temperature:37?,stirring speed:200rpm,pH:7,ratio of trace metal element:FeSO4·7H2O=67 mg/L,MgSO4 ·7H2O=580 mg/L,CaCl2=49.15 mg/L,MnSO4·H2O=0.385 mg/L,CoCl2·6H2O=0.2 mg/L,CuSO4·2H2O=0.093 mg/L.Under the above condition,both the degradation effect and bacteria growth of JNCP could increase obviously.Via study of degradation characteristic of Rhizobium JNCP,this study can provide theoretical basis and basic parameter reference to the application of JNCP in treatment of Phenol industry wastewater,which is essential to pollution control of wastewater containing phenol and water environmental quality of oil refining and food processing industry.