| Styrene is a kind of hydrophobic volatile organic compounds（VOCs）with a certain degree of toxicity,which not only causes harm to the environment,but also causes great harm to the human body.With the development of society,the use of styrene has become more and more extensive,involving multiple industries,so it is necessary to increase its governance.Biotrickling filters（BTFs）have attracted more and more attention at home and abroad due to their low cost,easy operation,and no secondary pollution.In this study,the biodegradation characteristics of styrene,packing characteristics,BTFs process development and other studies were carried out on the material basis of A.Hermannii ST10 independently bred,and the BTFs independently designed and commissioned processing as the experimental platform.Based on the theory of adsorption and absorption of biofilms,the biological removal mechanism of styrene was explored by using biodegradation and mass transfer kinetics model.The main results are as follows:（1）Using wastewater samples taken from the absorption tower of a chemical material company in Zhuhai and a lubricant branch company in Chongqing as the separation source,through sample domestication,enrichment culture,secondary domestication,plate separation and purification,and degradation ability characterization experiments 2 strains of styrene-degrading bacteria were screened out,and they were identified by 16S r DNA:both strains were positive for Gram staining.The identification results were Bacillus albus and Atlantibacter hermannii,and they were named B.albus ST6 and A.hermannii ST10.（2）A.hermannii ST10 has relatively stronger styrene degradation ability and was selected for the experimental strain.In view of the fact that there are few reports on the biodegradation characteristics of this strain,a study on the optimization of cell growth and substrate degradation conditions was carried out.The optimal process conditions were screened to be p H 7.0,culture temperature 32°C,and shaker rotation speed 120 r·min-1,the inoculation amount is 8%;under optimized conditions,the removal rate of 1500 mg·m-3styrene by A.hermannii ST10 can reach 92.85%.In the range of styrene concentration of25-1900 mg·L-1,the biodegradability of A.hermannii ST10 was found to be 1800 mg·L-1.Based on the biodegradability,The Haldane’s model was used to describe the kinetic behavior of cell growth and substrate degradation,and the residuals obtained were 1.44×10-4and8.88×10-4,indicating that the model has high accuracy.（3）In the double-tower experiment with polyurethane foam（PUF）as the filler,the influence of factors such as intake concentration,intake flow,gas-liquid ratio,and filler layer height on the working performance of BTFs was studied,and it was concluded that The suitable operating conditions are:inlet gas concentration 100～1500 mg·m-3,residence time26.2～60.1 s,gas-liquid ratio 100～60,and the removal rate increases with the increase of the packing layer,and decreases with the increase of inlet gas concentration.In addition,comparing the effects of different fillers on the removal efficiency of styrene,it was found that the PUF-Raschig ring mixed packing balanced the problem of hanging film and blocking,and received a good treatment effect.The removal rate of 94.12%was higher than that of single packing under the same conditions,and the operation of BTFs was more stable.（4）The experimental data was used to verify the kinetic model.The study showed that the experimental data was basically consistent with the calculated value of the model,which proved that the degradation of styrene waste gas by the strain A.hermannii ST10 conforms to the first-order kinetic model in the"absorption-biofilm"model And the"adsorption-biofilm"model,these two models can be used to roughly predict the removal effect of BTFs on styrene in this study.This experiment is based on the BTFs independently designed by the experimental group and the obtained high-efficiency degrading styrene strains.The aim is to improve the performance of BTFs in degrading styrene waste gas.The research results have certain practical significance for the improvement of BTFs performance and industrial application. |
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