Influence of physico-chemical properties of porous microcarriers on the adhesion of an anaerobic consortium

Abstract

The ability for biomass colonization of four porous mineral microcarriers (sepiolite, clay, pozzolana and foam glass- PoraverTM), was studied and related to their surface properties. The surface hydrophobicity of the mineral carriers was a more important factor influencing colonization by the anaerobic consortium than was surface charge. It was possible to correlate linearly the degree of hydrophobicity with the biomass retention capacity. Although the thermodynamic theory did not explain adhesion, an increase in cell attachment was directly related to the decrease of the positive values of the free energy of adhesion. Surface roughness, porosity and the amount of surface Mg²+, were also determinant factors in bacterial immobilization. However a great biomass accumulation can originate a decrease in biological activity due to mass transfer limitations.