Different dilutions of the biogas stream produced in the AD at an initial concentration of 3000 ppmv of H2S were prepared by mixing the biogas with humidified air. Two empty-bed residence times (EBRT), 31 and 85 s, were chosen for the performance of the reactor during the H2S and VFA biodegradation tests. Increasing mass loading rates from 99 g/m3h to 400 g/m3h (corresponding to 850 and 3000 ppmv H2S) were used for evaluating H2S removal at both EBRT. Gas samples of the inlet and outlet ports of the biofilter were periodically collected and diluted in 10 L Tedlar bags before taking measurements to determine the H2S and VFA consumption in the biofiltration system. Details of the analysis conditions were previously reported in Ramirez-Saenz et al., 2009.