Study On The Characteristics Of Mineralized Phenol From N2 Bacteria And Ff Bacteria With Differences In Ring-opening Cleavage Pathway

Phenol is an important raw material for the synthesis of phenolic resins,pesticides,dyes and other chemical products.Because of its wide application and large consumption,phenol has serious pollution and harm.Two groups of strains which could efficiently degrade phenol were isolated and screened from the previous research group.One is a way of splitting phenol with two adjacent open rings,which metabolize the complex intermediate products and low mineralized efficiency of Pseudomonas schiannae N2;the other is FF,which only cleavage phenol through the adjacent open ring,the intermediate product is simple,and the mineralization efficiency is high.The purpose of this paper is to study the characteristics of metal ions and their nitrogen sources on the metabolic and mineralized phenol of the two strains,and to study the characteristics of the combined combined degradation of phenol and to lay the foundation for the treatment of the actual phenol wastewater.In this paper,the effects of nitrogen source,constant metal ions Ca²⁺,Fe³⁺and Mg²⁺on the phenol metabolism of N2 and FF bacteria were studied by modern analytical testing methods,and the characteristics of two bacteria combined degradation of phenol were studied.Get the following results:（1）The addition of Fe³⁺can significantly improve the efficiency of phenol metabolism in N2 bacteria.The optimum range of Fe³⁺concentration is 0.9-1.35 mg/L.Mg²⁺has a similar promotion effect on the degradation of phenol by N2 bacteria.The optimum concentration range is 12-18mg/L,and the corresponding Ca²⁺is corresponding to the Fe³⁺.The effect is not obvious,and its suitable concentration is4-6mg/L.Fe³⁺enhanced the efficiency of N2 bacteria to degrade phenol because it could activate the catechol 2,3-double oxygenase in crude enzyme.（2）Ammonium nitrate is the most suitable nitrogen source for the degradation of phenol by N2 bacteria.Compared with ammonium chloride,sodium nitrate,sodium nitrite and urea,ammonium nitrate can obviously improve the activity of catechol 2,3-double oxygenase in cells,accelerate the opening of the phenol interposition,change the accumulation characteristics of intermediate products,and be beneficial to the mineralization of the degradation system.（3）Rhodococcus erythropolis FF with phenol as the carbon source,ammonium nitrate as the nitrogen source,initial pH value 7.0-8.0,Ca²⁺,Fe³⁺,Mg²⁺in 4-6 mg/L,0.45-1.35 mg/L,12-18 mg/L respectively,20 h can completely degradation of 400mg/L phenol,and can make phenol mineralization up to 65.8%.（4）The combination of N2 and FF can degrade phenol better,and the best ratio is N2:FF=1:3.Under this ratio,phenol can be completely degraded within 20 h when phenol is 400 mg/L.The interaction of complex bacteria can optimize the distribution characteristics of intermediate products,and help to mineralized phenol carbon source,the mineralization rate of phenol can reach as high as 74%,which is 13.4%and7.4%higher than that of single N2 and FF bacteria respectively.