ACTIVATED CARBON AND SYNTHETIC RESINS AS SUPPORT MATERIAL FOR METHANOGENIC PHENOL-DEGRADING CONSORTIA - COMPARISON OF SURFACE CHARACTERISTICS AND INITIAL COLONIZATION

Experiments were conducted to investigate the roles that activated carbon and synthetic ion-exchange resins perform as support material for methanogenic phenol-degrading consortia. The most important features of a support material, among those studied, were the availability of accessible pore volume and associated surface area for the colonization of microorganisms. The support material with the largest accessible surface area and pore volume, an anion-exchange resin, possessed the highest adsorption capacity for C-14-labeled Pseudomonas aeruginosa cells and supported the greatest number of methanogenic phenol-degrading consortia on its surface, as observed by scanning electron microscopy. Activated carbon had a higher total surface area than the anion-exchange resin but a smaller fraction was accessible to bacteria. The anion-exchange resin exhibited a negligible capacity for phenol adsorption. A substantial decrease in the apparent rate of phenol adsorption by activated carbon coincided with substantial colonization of the activated carbon pores by bacteria. The capacity for phenol adsorption was also reduced over the duration of substrate draw and feed experiments. No substantial benefit to bacterial colonization was observed to arise from the phenol adsorption capability of activated carbon in comparison with the anion-exchange resin.