Toluene degradation in biofilter: Sequencing the nutrient addition

Biofiltration is a cheap and effective method for purification of air stream with dilute contamination of volatile organic compounds. Toluene is industrially important VOC. The biological degradation of toluene was studied in a bench scale biofilter where coir pith was used as filter media. Nutrients play a crucial role in facilitating the degradation efficiency. Nutrient level in the biofilter media is to be maintained at a particular level, below which, the efficiency of the biofilter reduces. Under optimized condition, depletion of nutrients became slower and infrequent replacement of nutrient laden pith at the topmost layer of the biofilter was enough for maintaining the good removal efficiency. The pH of the media was maintained slightly above neutral without any further addition of buffer except during start-up.