Biofiltration of xylene polluted air with a new filtering bed composed of cellulose

The problem related to air discharge contaminated with volatile organic solvents (VOS) is the scope of numerous researches. Throughout the last decades, the development of different types of bioreactors to treat atmospheric emissions contaminated with VOS has been observed, such as: the bioscrubber, the percolating filter and the biofilter. These bioreactors are processes that use microorganisms in order to degrade the VOS into carbon dioxide, water, and biomass. This paper presents the results of a study on degradation by biofiltration of xylene contained in air, with a new filtering bed composed of cellulose. We have studied the conversion, the capacity of elimination of xylene with respect to the inlet load and the production of carbon dioxide. An elimination capacity of 75 g.m(3.)h(1) for an inlet con centration to the biofilter of 1.7 g.m(3) of xylene has been obtained, which is a value that is superior to values mentioned in the literature. Measurements of temperature, pressure drop, and moisture content have been taken regularly so as to evaluate the influence of these parameters in the degradation process of xylene by microorganisms. Counts of bacteria and yeast/mould present in the filtering bed have been performed in order to follow the evolution of these micro organisms. At last, modeling based on the Ottengraf's model (1986) has been developed with the experimental data.