Biodegradation of mono-chlorobenzene by using a trickle bed air biofilter (TBAB).

ABSTRACT

In the present study, performance of the trickle bed air biofilter (TBAB) for treating mono-chlorobenzene (MCB) was evaluated for various influent volatile organic compound (VOC) loadings using coal and mixed consortium of activated sludge as the packing material. Microbial acclimation to MCB was achieved by exposing the system continuously for 31 d to an average inlet MCB concentration of 0.688 g m-3 at an empty bed residence time (EBRT) of 188 s. The TBAB achieved maximum removal efficiency of 87% at an EBRT of 188 s for an inlet concentration of 0.681 g m-3, which is quite significance than the values reported in the literature. Elimination capacities of MCB increased with an increase of the influent VOC loading, but an opposite trend was observed for the removal efficiency. The maximum elimination capacity of the biofilter was 110.75 g m-3 hr -1 at an inlet MCB concentration of 1.47 g m-3. The effect of starvation on the TBAB was also studied. After starvation, the TBAB lost its ability to degrade MCB initially. However, the biofilter recovered very quickly. Evaluation of the concentration profile along the bed height indicated that the bottom section of TBAB has the best performance for all concentrations. By using Wani’s method of macrokinetic determination based on simple Monod kinetics, the maximum removal rate of MCB, rmax and saturation constant Km was to be found as 1.304 g m-3 s-1 and 113.446 g m-3, respectively.