Patent ID: 8057673

Claim:
A system for treating wastewater containing ammonia, comprising: an ammonia oxidation reactor, comprising biological carriers for carrying ammonium oxidation bacteria and nitrite oxidation bacteria, a pH level controller for increasing the pH level of the ammonia oxidation reactor to more than 7.5, and a dissolved oxygen (DO) controller for reducing the DO content of the ammonia oxidation reactor to less than 1.0 mg/L, and a membrane reactor disposed downstream of the ammonia oxidation reactor, wherein the membrane reactor comprises a membrane and an air aerator for separating solids and liquids in an effluent of the ammonia oxidation reactor and yielding an oxygen rich liquid effluent, wherein the DO controller controls the DO content of the ammonia oxidation reactor by controlling a reflux ratio of the oxygen rich liquid effluent that is conducted back to the ammonia oxidation reactor.