Microbial Degradation Pathways of Acrylic Paint Thinner Gas in Biotrickling Filter and Comparison of Kinetic Models Under Different Gas Concentrations

Abstract

In this study, the effect of inlet concentration of pollutants, empty bed residence time (EBRT) and liquid recycling velocity on the performance of the BTF was explored. The results showed the best operating characteristics of the biotrickling filter for this study were at an inlet concentration of 500 mg/m3�Cthe EBRT of 300s and liquid recycling velocity of 25.46 m h-1. At this condition, the total removal efficiency of pollutants can reach more than 90%. Among them, the removal efficiency of toluene and ethylbenzene was above 95%, and the xylene (m-xylene, o-xylene) could reach more than 70%, corresponding to elimination capacities (ECs) of 3.02 �} 0.33 g m-3 h-1, 1.81 �} 0.2 g m-3 h-1, 0.60 �} 0.07 g m-3 h-1. Through the fatty acid identification system and 16S rDNA identification, it could be found that the four dominant bacteria (Bacillus cereus, Bacillus subtilis, Acinetobacter calcoaceticus, Belem Bacillus) had a significant effect on the removal of acrylic paint thinner. According to the detection of organic compounds by gas chromatography and the corresponding enzymes produced by four dominant bacteria, the pathways for microorganisms to degrade pollutants could be inferred. The absorption-biofilm theory and the adsorption-biofilm theory were used to simulate and verify the degradation process of exhaust gas at different concentrations respectively.