Effects of Temperature and pH on characteristic of Immobilized Microorganisms Gel and Removal of High Ammonium-nitrogen

Abstract

The effects of temperature and pH on characteristic of immobilized microorganisms and the removal of ammonium nitrogen were investigated. The activated sludge was entrapped in polyethylene glycol gel, and elastic pellets containing activated sludge were obtained. The life of the pellets in terms of compressive strength was estimated with Arrhenius equation. The result indicated that the life of the pellets was at least 5 years at a pH from 6 to 9, and at a temperature under 40 °C. Wastewater contained 95260mg·l^-1 of ammonium nitrogen was treated with pilot plant by immobilized microorganisms over a retention time of 6 h. Influent NH₄-N could be removed and the removal was 98%. Practical plant with 140 m³ of aeration tank was operated and the wastewater could be treated at the retention time of 7 h.