Waste Gas Treatment in Biofilters

Biofiltration of polluted gas streams containing malodorous triethylamine (TEA) was studied. The experiments were conducted in a laboratory-scale reactor with a mixture of sieved compost and chaff particles as the filter material on which the microorganisms were immobilized. The concentrations of TEA in the inlet gas varied from 0.32 to 3.45 g/m³ (78 ppmv to 841 ppmv), while the superficial velocity of the inlet gas ranged from 60.1 to 322.2 m/hr. The removal efficiency of triethylamine in the biofilter decreased as the gas velocity or TEA concentration in the inlet gas increased. Moreover, the elimination capacity of this biofilter could reach up to 140 g/(m³ hr). When the loading of TEA exceeded this critical value, substrate inhibition occurred and the elimination capacity decreased. A mathematical model predicting the removal efficiency of the pollutant was also developed in this study. The inhibitory effect of the substrate on the growth rate of the biomass was considered in this model. The proposed model could accurately represent the experimental data obtained in this study.