Study On The Degradation Of Volatile Phenol In Coking Wastewater By N2 And FF Bacteria And Their Synergistic Effect

Cresol and phenol are commonly found in actual coking and other phenol-containing wastewaters,and they have a high content.They are triad aromatic organic compounds,which are harmful to aquatic plants and plants at low concentrations and are easy to accumulate in living organisms.Traditional water Processing techniques are difficult to remove.Bioaugmentation technology is expected to solve this problem.In the early stage of the research group,two strains of rapid phenol-degrading bacteria,Pseudomonas stutzeri N2 and Rhodococcus erythropolis FF,were isolated and screened.In order to apply the two strains to the treatment of actual phenol-containing wastewater by bio-enhancement technology,it is not clear whether the two strains degrade the characteristics of three cresol isomers which are often present in phenol-containing wastewater,and it is not clear.The two strains compounded and decomposed the characteristics of volatile phenols in various wastewaters.Based on this,this paper carried out related research,which has the main theoretical and practical significance for bio-enhanced technology to treat actual coking wastewater.In this paper,UV analysis,liquid chromatography,TOC analyzer and gas chromatography-mass spectrometer are used to select three kinds of volatile phenolic o-/inter-/peer phenolic wastewater.Phenol isomers and phenol are the tested pollutants.The process conditions of N2 and FF bacteria for the degradation of each single pollutant and its mixed pollutants are studied,and the treatment conditions applied to the actual coking wastewater treatment are studied.Results:(1)Pseudomonas stutzeri N2 can grow with m/p/o-cresol as the sole carbon source andenergy source,respectively.Can completely degrade the conversion or p-cresol.O-cresol is most difficult to be metabolized due to its high toxicity.At its optimum temperature of 200mg/L,its degradation rate is only 11.38% at 48 h.However,when three kinds of cresols are mixed,it can be observed that the carbon sources synergistically promote transformation and mineralization.(2)The intermediate products of N2 bacteria degrading three cresols are mainly hydroxybenzaldehyde/acid,dihydroxybenzoic acid,ring-opening product 2-hydroxy-4-carboxy-3-hexenoic acid,2-hydroxy-4-carboxyl group-2,4-hexenoic acid,2-hydroxy hexanoic acid,2-hydroxypentane/succinic acid,and the like.Hydroxybenzoic acid intermediates inhibit the growth of N2 bacteria.The beneficial route for N2 bacteria to degrade three cresols is that the methyl group is oxidized to aldehyde and carboxylic acid,and then hydroxylated.After ring opening and cracking of the aromatic ring,the decarboxylation is gradually degraded to mineralization.(3)N2 and FF bacteria can jointly transfer two kinds of volatile phenolic compounds such as cresol(m-/p-cresol)and phenol,which can grow well in the total concentration of the mixture up to 900mg/L.Among them,N2 bacteria: FF bacteria = 2:6 ratio,the cell growth was the fastest,the total phenol and the TOC removal efficiency was the highest.The total concentration of complete degradation conversion was 600mg/L,900mg/L mixed phenol only 18 h respectively.And 24 h.When o-cresol is added,that is,three kinds of volatile phenols such as three cresols(p-/m-o-cresol)and phenol coexist,the toxicity of o-cresol is relatively high,and the total concentration of the optimal mixed phenol is reduced to 500mg/L.However,under these conditions,the cells can still grow normally.When inoculated with N2 bacteria: FF bacteria = 2:6 ratio,the cell growth metabolism is the fastest,and the degradation rate,mineralization effect and COD removal rate are the best.The optimum mixed inoculation was 8%,and the initial optimum pH of the degradation solution was 7.5.(4)Mixed inoculation of N2 and FF bacteria,the cells can grow with the actual coking wastewater pollutants as carbon source,and show synergy between growth and inoculation,which can quickly adapt to the toxicity of actual coking wastewater and enter the logarithmic growth period in a short time..Over time,the phenol and cresol in the coking wastewater are continuously degraded and transformed,and the accumulated acidic intermediates lower the pH of the degradation solution.The removal rate of COD in the actual coking wastewaterwas about 74%.Therefore,the bio-enhancement technology N2 bacteria and FF bacteria are mixed and inoculated into the actual coking wastewater,and a good treatment effect can be obtained.