Determination of design parameters and cost-effectiveness analysis for a two-liquid phase biofilter treating gaseous dichloromethane

摘要

Two-liquid phase biofilter (TLPB) is a new type biofiltration system for controlling hydrophobic volatile organic compounds. In this paper, a mathematical model was developed for a TLPB that can treat gaseous dichloromethane (DCM). The specific growth rate of the biomass inside the TLPB fitted the Monod model. u(max) and K-s were 0.013 d(-1) and 1.288 g m(-3), respectively. The Henry's Law constant of the two liquid phase mixtures was obtained as 0.125 kPa m(3) mol(-1) under the addition of 10% silicone oil. Simulation results revealed that the model is a good tool for evaluating the removal performance of TLPB. Practical applications of the model indicated that an increase in the silicone-oil-to-mixture ratio and inoculated biomass improved the removal efficiency, whereas an increase in the inlet DCM concentration and gas velocity negatively affected the removal performance. Moreover, the model can be used to determine the design parameters and ensure that the outlet concentration satisfies the emission standards. The results of cost-effectiveness analysis indicated that the expenditure for DCM removal per year was low when TLPB was used to treat a high DCM concentration steam with a long empty-bed retention time.