Performance of peat/wood chips media as a biofilter packing material for the treatment of an industrial waste gas

Abstract

A study was conducted to evaluate the removal efficiency of NH3 and H2S emitted from an industrial waste gas source by bio-filtration with peat/ wood chips media (50/50 (v/ v)) as a bio filter packing material. A pilot plant testing was carried out using peat samples from Muthurajawela, Sri Lanka and wood chips in the size range of 5 mm to 25 mm. The void age of the packing material was in the range of 50-70%. The experiments were carried out over an effective bio filter operational period of 45 days under intermittent loading (8 hours on weekdays only). Thin film micro sensors capable of sensing an array of industrial pollutants were used in measuring the concentration of NH3 and H2S in the contaminated air stream and found to be in the range between 43-90 ppm and 70-100 ppm, respectively. Results indicated that 100% removal efficiency of NH3 and H2S can be achieved for peat/wood chips medium. The maximum elimination capacity for NH3 was 5.59 gm^h1 and the H2S maximum elimination was 6.99 gm^lr1. The study was conducted as a preliminary evaluation of the suitability of peat/ wood chips media as a packing material for an industrial scale bio filter for the treatment of the same waste gas stream.