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Indoor air pollution (IAP), defined by a lot of pollutants at low concentrations (microg m(-3)), is recognized as a major environmental health issue. In order to remove this pollution, biofiltration was investigated in this study. Two biofilters packed with compost and a mixture of compost and activated carbon (AC) were compared during the treatment of an influent with characteristics close to those of IAP. Very high removal efficiencies (RE) were achieved for the two biofilters (RE more than 90% for butyl acetate, butanol, formaldehyde, limonene, toluene and undecane at mass loading from 6-24mg m(-3) h(-1) and 19s empty bed retention time). The fact that high RE of hydrophobic compounds (undecane and limonene) were achieved, along with the results of an abiotic sorption study, lead us to suggest a mechanism including adsorption followed by biodegradation at the interface of the biofilm where microorganisms tend to concentrate near the available substrate. Both chemical reactions with the packing materials and biological degradation led to average RE greater than 91.4% for nitrogen dioxide. It was observed that adding AC to compost had significant effects. First, its buffering capacity led to shorter acclimation duration and more stable operation efficiencies than for the compost biofilter. Secondly, the only compound which was not removed by the compost biofilter, trichloroethylene, was strongly adsorbed by the compost/AC biofilter. Finally, the concentration profile along the two biofilters demonstrated that adding of AC could lead to a reduction of the retention time required to reach the maximal RE.

Indoor air pollution, characterized by many pollutants at very low concentrations, is nowadays known as a worrying problem for human health. Among physical treatments, adsorption is a widely used process, since porous materials offer high capacity for volatile organic chemicals. However, there are few studies in the literature that deal with adsorption as an indoor air pollution treatment. The aim of this study was to investigate the adsorption of toluene on to activated carbon at characteristic indoor air concentrations. Firstly, global kinetic parameters were determined by fitting Thomas's model to experimental data obtained with batch experiments. Then, these kinetic parameters led to the determination of Henry's coefficient, which was checked with experimental data of the adsorption isotherm. Secondly, we simulated a breakthrough curve made at an inlet concentration 10 times higher than the indoor air level. Even if the kinetic parameters in this experiment are different from those in batch experiments, it can be emphasized that the Henry coefficient stays the same.

The aim of the present work is to study the effect of different activation methods for the production of a biomass-based activated carbon on the CO 2 and CH 4 adsorption. The influence of the activation method on the adsorption uptake was studied using three activated carbons obtained by different activation methods (H 3 PO 4 chemical activation and H 2 O and CO 2 physical activation) of olive stones. Methane and carbon dioxide pure gas adsorption experiments were carried out at two working temperatures (303.15 and 323.15 K). The influence of the activation method on the adsorption uptake was studied in terms of both textural properties and surface chemistry. For the three adsorbents, the CO 2 adsorption was more important than that of CH 4 . The chemically-activated carbon presented a higher specific surface area and micropore volume, which led to a higher adsorption capacity of both CO 2 and CH 4 . For methane adsorption, the presence of mesopores facilitated the diffusion of the gas molecules into the micropores. In the case of carbon dioxide adsorption, the presence of more oxygen groups on the water vapor-activated carbon enhanced its adsorption capacity.