Study On Heat And Mass Transport Characteristics And Purification Performance In Trickling Biofilter For Low Concentration VOCs Removal

In recent years, many industrial processes, such as organic chemistry industry, coal industry, rubber regeneration and paint spraying, etc., use and emit the low concentration volatile organic compounds (VOCs) and the stench gas, which has already seriously polluted the atmospheric environment of some areas. The recovery of low concentration VOCs is valueless and its treatment is very difficult and expensive for traditional physical and chemical treatment technologies. The biological treatment technology of VOCs has become a research hotspot in the world because of high purification efficiency, cost-effective, and environmentally friendly etc. The three most widely used biological reactors for VOCs treatment are biofilter, trickling biofilter, and bioscrubbing filter. Trickling biofilters have been shown in several instances to be superior to biofilters when accurate controls of the environmental conditions or higher pollutant elimination rate are required. Understanding deeply the two-phase flow characteristics, mass and heat transport characteristics, and microorganism biochemistry reaction characteristics in trickling biofilter bed is the fundamental of developing technology for VOCs treatment using trickling biofilter.The experiments on the start-up and purification performance for low concentration toluene treatment of trickling biofilter with ceramic spheres were investigated in the present study. Besides, the experiments were conducted to evaluate the temperature profile characteristics of trickling biofilter bed. Combined with two phase flow theory, a theoretic model was established for describing gas-liquid flow, mass and heat transport processes, and biochemical reaction characteristics.1) The microorganism from collection of the living earth was cultivated and domesticated, which bacterial strain with high toluene degradation capability was received. The bacterial strain belongs to Pseudomonas Putida.2) The experiments on the start-up of trickling biofilter were conducted which firstly obtained the evaluating status for start-up accomplished. The experimental results show that the start-up progress of trickling biofilter included biofilm formation period, development period, and stabilization period. The similar change tendency of OD600nm of circulation liquid, the pressure drop of gas in packed bed, the elimination capacity of pollutant can be used to evaluate the start-up status of trickling biofilter. The inlet toluene concentration, OD600nm of circulation liquid,...