Isolation And Screening Of Marine Mud Microorganisms And A Study On The Degradation Of Phenol Cyanide Wastewater

Coking wastewater contains a large amount of phenol and cyanide.Both phenol and cyanide are highly toxic substances,and the biological method is recognized as an effective and environmentally friendly method.In this paper,a bacteria strain JQBF100 was obtained by separating and screening marine mud microorganism.It was found that it can degrade phenol and free cyanide in the same solution.In this paper,the researchers constructed the microbiological screening method for the marine mud microorganism wanted.The screening way was to use direct daubing method(MDD)to obtain 20 strains from the sea and to preserve them through the screening of medium with different concentrations of high salinity.Among them,JQBF100 has the capability of degrading free cyanide and phenol.The second part mainly verified the degradation characteristics of the strain JQBF100 on the free cyanide.Firstly,the effect of pH factor on the performance of JQBF100 was studied.The results showed that the optimal pH value of the degradation activity was 7-9,while the optimal pH value of cell tolerance was 7-9.6.Under the optimum pH condition,a certain concentration(OD600=0.75)of JQBF100 cell suspension could degrade the 350mg·L-1 free cyanide completely at a constant rate in 20 minutes,and the initial degradation rate of free cyanide was independent of its concentration.The Results of product analysis showed that degradation approach of JQBF100 on free cyanide was hydrolysis,at the same time produced formic acid and formamide(mole ratio of 8.5:1).after the free cyanide was degraded completely,formamide could generate formic acid and NH4+ under amidase,and formic acid also could be generated by JQBF100 at last.In the third part,the researchers studied the degradation of phenol ammonium system by bacterial JQBF100 alone,and further studied the degradation performance of JQBF100 on phenol cyanide system.Results showed that compared with phenol ammonium system,stagnation period of the same concentration of phenol degradation could be greatly reduced by CN-.JQBF100 could degrade the initial phenol cyanide concentration(1000:100 and 500:500)in the inorganic salt solution without other C and N sources.the product of free cyanide in the phenol cyanide system did not change,moreover phenol and product formic acid had slight inhibition on each other.phenol was degraded as the degradation of formic acid.At the same time,the researchers found that in phenol cyanide system,JQBF100 catalytic activity and cell tolerance could tolerate environment of pH 11.26.The potential capacity of JQBF100 in real water environment is worth further exploring.