A compact A²O MBR system for water reclamation in the northwestern China - a case study

Based on the successful adoption of A²O membrane bioreactor (MBR) system with 2.5 times treatment capacity (5,000 m³/d) rather than conventional activated sludge process (2,000 m³/d), A domestic wastewater treatment plant in the northwestern China was greatly upgraded that can effectively meet the requirements of wastewater treatment and reclamation. In the A²O process, with high-depth aeration (11.0 m), high organic and ammonia nitrogen removals were achieved synchronously in a wide range of sludge retention time. This system could be also strategically controlled to achieve high-phosphorous removal by optimized discharge of excess sludge. This project provided the first case study of A²O MBR system in the cold region and showed the advantages of membrane technology for water reclamation in water-deficient areas of China.