Study On Biodegradation Technique For VOCs

Three biotrickling filters (BTFs) packed with plastic Pall ring and columned activatedcar-bon have been developed, and the removal efficiency (RE) and elimination capacity (EC)of low concentrated benzene（5～200ppm）and n-hexane（5～200ppm）were investigated. Thestart-up process of biofilm has been analyzed. Several operational parameters includingperformance of packing materials, height of packing materials, gas residence time, benzeneand n-hexane inlet concentration, which influence the removal efficiency, were testedexperimentally. Optimized operational parameters were summarized，in order to direct thebiodegradation process of low concentrated VOCs in confined space.In the benzene inlet loading range of1.57mg/(L·h)～125.38mg/(L·h), the maximumeli-mination capacities of BTFⅠ、Ⅱ、Ⅲ for benzene reached22.7mg/(L·h)、29.14mg/(L h)、60.27mg/(L·h) respectively. While the maximum elimination capacities for n-hexanereached27.81mg/(L·h)、72.21mg/(L·h)、77.92mg/(L·h) for BTFⅠ、Ⅱ、Ⅲ, with the n-hexaneinlet loading range of2.01mg/(L·h)～160.74mg/(L·h). In biodegradation experiments forbenzene and n-hexane, BTFs have been operated steadily for4months and3months. Theresults com-monly indicated that compound packing materials displayed higherbiodegradation efficiency than that of above two single packing materials.A kinetic model for the biodegradation process was founded based on gas-liquid phasetheory and adsorption-biofilm theory. Good pertinences had been shown betweenexperimental data and calculated data. The interrelation coefficients were0.88for plastic Pallring as packing material, and0.92for columned activated carbon as packing material inbenzene biodegradation process. The results revealed that the kinetic model was reliable forbiodegradation process with BTFs.