Development of a carrier for adhesion of nitrifying bacteria using a thermodynamic approach

Biopop, a novel modified cellulose carrier for nitrification was developed through thermodynamic analysis of carrier materials. By measuring contact angles among nitrifying bacteria, solid carrier and broth, the change in free energy of adhesion of nitrifying bacteria on carrier (δG) was calculated. Cellulose gave the most favorable free energy change for adhesion of nitrifying bacteria and all the inoculated microbes were attached on porous carrier made of cellulose within 1 day. The new carrier gave a nitrification rate (800 g N-NH /m day), which was about four times higher than other carriers made of synthetic polymers such as polyurethane or rubber.