MICROORGANISM CARRIER AND SEWAGE TREATMENT APPARATUS

摘要

PROBLEM TO BE SOLVED: To obtain a microorganism immobilization carrier for a fluidized bed which is excellent in both affinity for water and microbial adhesion, has resistance to both breakage and wear, and retains water treatment performance restoring force even after being under a condition of load depletion. SOLUTION: This microorganism carrier for sewage treatment is made up from a thermoplastic resin foam made mainly of a hard thermoplastic resin such as high-density polyethylene, polypropylene or polystyrene and having continuous bubbles. The maximum diameter and the minimum diameter of one particle are >=2 mm and <=25 mm, respectively. The specific surface area of the foam is 5 to 50 m2/cm3. A fluidized-bed sewage treatment apparatus which performs the treatment under an aerated condition is constituted by filling the microorganism carrier in a bulk volume of 5-50% based on the aqueous-phase volume of an aeration tank.