[Removal characteristics of DCM by biotrickling filter and biofilter]

A biofilter (BF) packed with nutrition slow-release material and a biotrickling filter (BTF) packed with ether-based polyurethane foam were set up to remove dichloromethane (DCM) from exhaust gas. Results showed that the biofilm formations in BTF and BF were completed by using the mixture of a special strain and a bacterial community, within 25d and 22d, respectively. Through the observation of the filter surface by SEM, the surface of packings in BF was loose with thin biofilm colonies, whereas the one in BTF was dense with thick biofilm. Under the condition of inlet DCM concentration of 100-1,500 mg x m(-3), EBRT of 25-85 s, the removal efficiency of DCM in BTF was better than that in BF, and the maximum removal load was 22.61 g x (m3 x h)(-1) and 29.05 g (m3 x h)(-1), respectively. The relationship between CO2 production and DCM removal was approximately linear, with the mineralization rate being 70.4% and 66.8% for BTF and BF, respectively. The dynamic behaviors of DCM in BTF and BF were described by the Michaelis-Menten model. Through the calculation, the unit volume maximum degradation rate r(max) was 22.7790 g x (m3 x h)(-1) and 28.5714 g x (m3 x h)(-1), while the gas phase saturation constant Ks was 0.1412 g x m(-3) and 0.1486 g x m(-3)