Bacillus Amyloliquefaciens Used For Accelerating2,4,6-trichlorophenol Biodegradation By Means Of UV Photolysis

Phenol and phenolic compounds are important industiral raw materials, andwidely used in many industrial ifelds, such as petroleum refining, resin, plastic,leather, textile manufactuirng, chemical and petrochemical plants，coke oven，casting，machining, rubber recycling plants, pharmaceutical，pulp and paper mills etc. But theyare also main pollutions existed in most industiral wastewater with stench, peculiarsmell and high toxicity. The industiral wastewater is very difficult to deal with it, Andwastewater discharge into the environment has a certain stability, Through themigration, the polluted area can be further expanded, The existence of chlorinatedphenolic compounds otfen make microbial metamorphism and loss of enzyme activityin the body, eventually lead to biological treatment effect is poorer, so using a singlebiological method is difficult to make the effective degradation. This study explorethe ultraviolet radiation to alleviate trichlorophenol effects on microorganisms,UseILPBR,Through alone photolysis, alone biodegradation, photolysis&biodegradation.Three methods for trichlorophenol degradation. And study the regular pattern ofdegradation, degradation kinetics and chlorine release regularity in the degradationprocess, To show that UV light and bioiflm synchronous coupling degradationmethods is very eiffciency. By the analysis of molecular biology，To study the functiongenes of the microbial degradation of TCP, explore the mechanism of microbialdegradation TCP.A strain was isolated rfom acclimated activated sludge for simultaneousbiodegradation of phenol and2,4,6-trichlorophenol （TCP），which was identified asBacillus amyloliquefaciens strain by16s rDNA amplification. B, amyloliquefacienswas used for phenol biodegradation at presence of TCP to investigate inhibition ofTCP on phenol degradation as well as the bacteira growth. At the same time，UVphotolysis was employed to relieve the inhibition to accelerate phenol removal rate.Experimental results suggested that UV photolysis could relieve the inhibition of TCPon the bacteria effectively,because UV photolysis converted TCP into itsintermediates, which has less inhibition to the bacteira. Biomass growth demonstratedMonod kinetics, when phenol alone were used as substrate and in the range ofexperimental concentration （25?200mg/L）. Get the biggest/imax and the smallest Ksvalues, and when TCP was added into phenol solution, the “赚decreased by26%,and ATS increased by319%，but when the TCP was illuminated with UV light, the//maxincreased from1.08h"1to1.18h_l—, and Ks decreased from88mg*L】to56mg*L₁.The experimental results suggest that UV photolysis relieved inhibition of TCP to bioiflms.The mechanism why TCP was relieved was thought to form its photolysisproducts （intermediates）, which were proposed to be mainly4-monochlorophenoI（4-MCP） and2,4-dichlorophenol （2,4-DCP） at first by analyzing its metabolicpathway. And then4-MCP and2,4-DCP were respectively added into phenol solutionto investigate effect of them on phenol degradation and biomass growth todemonstrate that4-MCP had smaller inhibition than original TCP on phenoldegradation and biomass growth.In the study of Bacillus amyloliquefaciens’’ degradation characteristics ofchloirne phenol wastewater. Use it deal with the different mixing substrateswastewater. Inoculating different microbial concentration in simulated wastewaterwhich include homologous co-substrates （2，4，6-TCP+Phenol） and other co-substrates（2，4，6-TCP+Glucose、2+，4，6-TCPBenzoic Acid）. To study its response characteristicsof the substrates.Found that the microbial growth curve are consistent in differentinoculation concentrations. And Bacillus amyloliquefaciem has the most quicklyreaction in the2，4，6-TCP+Glucose co-substrates simulated wastewater and the mostslowly reaction in the2,4,6-TCP+PhenoI co-substrates simulated wastewater. Thebacteria also could grow very well without additional carbon source in alone TCPcase.In other study.Phenol as additional carbon resources?use this bacteria deal with4-MCP、2,4-DCP>2，4，6-TCP、2,4,6-TCP（UV）.Found in both the flask experimentsand ILPBR reactor experiments chlorine phenolics has different degree of growthinhibition characteristics to Bacillus amyloliquefaciens. Inhibition of the intensity asfollows:2>>，4，6-TCP4-MCP〉2，4-DCP2，4，6-TCP （UV）.I,n the study of Bacillus amyloliquefaciens practical application in wastewaterand its function gene for TCP degradation, Choose this bacteria degrade2，4，6-TCP.Inthe shake flask degrade2,4,6-TCP simulated wastewater （5⁴0mg/L）. using theimmobilized biofilm in ILPBR（internal loop photolytic biofilm reactor） veriyf itstreatment effect; With the help of the combination of photolysis and biologicaltreatment synchronous coupling, the reinforcement of biological and secondaryutilization. In the shake flask experiments, Under the condition of alone TCP,Concentration of20mg/L2，4，6-TCP fully biodegradable in32hours，Atfer addphenol as additional carbon source，Concentration of20mg/L2,4,6-TCP fullybiodegradable in30hours. While in the ILPBR using immobilized biologicalmembrane to deal with2,4,6-TCP simulated wastewater. Compare the P+B and P&Btwo experimental protocols the degradation effect of2,4,6-TCP. In P+B protocol,20mg/L2,4,6-TCP is fastest under co-substrates was degraded completely finishedwithin120minutes, But In P&B protocol20mg/L2,4,6-TCP under co-substrates atfercan be degraded completely within30minutes. This suggests that the treatment effectof photolysis and biological synchronous coupling is very good.In the study ofBacillus amyloliquefaciens’ function gene for TCP degradation，The bacteira has atcp-like gene which could translate2,4,6-TCP monooxygenase.