Comparsion Of Thermophilic Biofiltration And Mesophilic Biofiltration Of Gaseous Toluene

With the development of society and economy,the emission and pollution of volatile organic compounds(VOCS)is becoming one of great environment concerns. Among the various technologies for VOCS treatment , biofiltration is widely considered a cost-effective technology because of its low operating costs and convenient maintenance. How to improve the biological filtration technology of VOCS removal performance of high temperature gas is the research focus. In this study, a thermophiles biofilter and a normal temperature biofilter were set up to remove gaseous toluene. Through a long time dynamic simulation, the biomass changes under various operating conditions in two biofilter's were investigated. Furthermore, two biofilter's the microbial metabolism characteristic changes is analysis.The performance of the thermophiles biofilter and normal temperature biofilter were compared. When the inlet toluene concentration is low (below 500mg m-3), the remove rate of toluene in thermophiles biofilter is more than 80%. When the EBRT reduced, the normal temperature biofilter's removal rate has significantly reduced, while the thermophiles biofilter's remain suable. So the thermophiles biofilter is more stable than the normal temperature biofilter under big flow. When the toluene concentration is more than1500mg m-3, the microbial activity in the thermophiles biofilter were suppressed.The result of three dimensional fluorescence spectra of two biofilter's leachate indicated that microorganisms in two biofilter both transform toluene into organic acids. In the thermophiles biofilter, the microbial's metabolism speed up in high temperature, autolysis happening at the same time. All this lead to the increase of leachate'TOC, but also maintaining the stability of the pressure and slowly growth rate of biomass. In the normal temperature biofilter, rapid growth of biomass lead to pressure drop is not stable, affect the normal operation of reactor. When unit quality microorganisms in two biofilter transform unit toluene, the thermophiles biofilter releases more CO2. But it has lass biomass, so the CO2 concentration in thermophiles biofilter's export is lower than normal temperature biofilter.Through the analysis of the characteristics of microbial metabolism, found that there are significant differences between two biofilter's metabolic features of different carbon source. For amine class, sugar and amino acids, the thermophiles biofilter's metabolic ability is strong, and of polymer, esters carbon source of metabolic ability is weak. the thermophiles biofilter for metabolic fungi carbon sources faster than for metabolic bacteria carbon sources,so it's advantage strains is fungi. The diversity of microorganism in two biofilter in increase with time, and the non-similarity between them is increase.