Influencing Factors On The Performance Of Anaerobic Microbial Degradation Of Phenol

Phenol is an important raw material for many chemical products,and its demand is increasing.At the same time,phenol is a kind of toxic and refractory organic matter.The pollution of phenol wastewater to the environment can not be ignored.The treatment of phenol wastewater has become a hot research direction,in which anaerobic microbial treatment method of phenol wastewater has been paid more attention by many scholars.In this study,anaerobic granular sludge was used to study the anaerobic degradation of phenol wastewater.Static acclimation device was used to acclimation granular sludge.After 69 days of acclimation,anaerobic microorganisms could successfully degrade phenol wastewater with different concentrations.When the phenol concentration was 300mg/L,the phenol removal efficiency was the best,and the phenol degradation ability reached28.35mg/gVSS·d.The influence of factors on phenol degradation was studied by using acclimated anaerobic granular sludge in order to explore the best control conditions for phenol anaerobic treatment.The results showed that the anaerobic microbial treatment of phenol had the best effect when pH was 6.6~6.8,ORP was about-280mV,DO<0.2mg/L and temperature was 35?.When the phenol was degraded by continuous operation,the removal rate of phenol was over 94%under the conditions of HRT of 24h and phenol loading of about 0.5kg phenol/(m~3·d),which was the best effect of anaerobic microorganisms in removing phenol.In order to further explore the internal mechanism of anaerobic microbial degradation of phenol,the experiment was carried out to analyze the extracellular polymer substances of granular sludge,and to determine the anaerobic degradation pathway of phenol by using GC/MS technology to detect the intermediate products in the process of phenol degradation.It was found that PN was the main substance to resist phenol toxicity.The main pathway of anaerobic degradation of phenol was determined as benzoic acid pathway.Phenol was first converted to benzoic acid,which was then transformed by microorganisms into long chain and short chain alkanes that were eventually degraded into acetic acid,isobutyric acid and other substances that were used by microorganisms.The evolution of dominant bacteria in phenol degradation was studied.The dominant bacteria in the degradation of phenol were identified by using high-throughput sequencing technology and using PCR to amplify 16S rDNA fragments in the study.The results showed that The five genus,Syntrophomonas,Candidate_division_OP8_norank,Syntrophorhabdus,Synergistaceae_unclassified,and Anaerolineaceae_uncultured interacted with each other to jointly degrade phenol and gradually evolved into phenolic dominating genus.