Biofiltration of methane using an inorganic filter bed: Influence of inlet load and nitrogen concentrationThis article is one of a selection of papers published in this Special Issue on Biological Air Treatment.

Abstract

An upflow lab-scale biofilter was operated with an inorganic filter material to control methane emissions. The influence of the inlet load on methane removal was investigated and the maximum elimination capacity obtained was 36 g/(m3·h) for an inlet load of 95 g/(m3·h). The influence of the nitrogen concentration, which was provided in the form of nitrate through a nutrient solution, was also determined. We established that the optimum nitrogen concentration required for biofilter operation decreases with the methane inlet load. In fact, it was around 0.75 g/L for inlet loads comprised between 55 and 95 g/(m3·h) and of 0.50 g/L when the inlet load was comprised between 20 and 55 g/(m3·h). During this study, a nitrogen concentration of 1.00 g/L inhibited methane removal in the biofilter. In addition, the use of a nitrogen concentration superior to its optimum level can cause, in the long-term run, severe damages to the biofilter performance.