USE OF ACTIVATED CARBON AS A BUFFER IN BIOFILTRATION OF WASTE GASES WITH FLUCTUATING CONCENTRATIONS OF TOLUENE

Fluctuations in contaminant concentrations often adversely influence t he effectiveness of bioreactors for waste gas treatment, Application o f an adsorbent to minimize such fluctuations could improve the overall process. Therefore the buffer capacity of a number of activated carbo ns and other adsorbents was tested. The buffer capacity of the adsorbe nts depends on the desired concentration range of the contaminants ent ering the bioreactor and on the time available for desorption. When fl uctuations between 0 and 1000 mg toluene m(-3) were applied to a biofi lter this resulted in significant concentrations of toluene leaving th e biofilter. Using one selected type of activated carbon it was demons trated that these fluctuations could be decreased to a value of about 300 mg m(-3), which was subsequently completely degraded in the biofil ter.