Peat-based toluene biofiltration: A new approach to the control, of nutrients and pH

This paper describes an eighty days toluene vapour removal from air by a peat-based biofilter to study the effect;of different inocula and nutrient supplies on the biofiltration efficiency. Four pure microbial strains were used for the inoculation of the biofilter matrix: i.e. Arthrobacter paraffineus, from the American Type Culture Collection (ATCC) and a further three aromatic hydrocarbons degraders selected from among those in private collections. The toluene inlet load was maintained at constant value throughout the trial . To improve toluene biofiltration, changes in the inoculation of the filter bed have been diversified. We have also investigated supply of nutrients by various aqueous solutions to humidify the filter packing material. Nutrients introduced by these solutions contained inorganic and organic nitrogen forms. To evaluate the influence of nutrient supplies, the operating parameter measurements have been monitored on an 80 day cycle. Parameters observed included the filter bed temperature, pressure drop and the toluene concentrations at both the entry and exit of the biofilter, the pH and physiological activities resulting from the various operational conditions.