Pure water and resource recovery from municipal wastewater using high-rate activated sludge, reverse osmosis, and mainstream anammox: A pilot scale study

• Published in: Water research (Oxford) Vol. 266; p. 122443
• Main Authors: Zhao, Haoran, Zhou, Yu, Zou, Lianpei, Lin, Chihao, Liu, Jianyong, Li, Yu-You
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.11.2024
• Subjects: Mainstream partial nitrification-anammox; membrane bio-reactor; Reclaimed water; Wastewater primary treatment; membrane bio-reactor; Wastewater primary treatment; Reclaimed water; Mainstream partial nitrification-anammox; RO
• ISSN: 0043-1354; 1879-2448; 1879-2448
• DOI: 10.1016/j.watres.2024.122443

•75 % of influent was converted as pure water with conductivity around 50 μS/cm.•Approximately 90 % of mainstream nitrogen was removed, primarily through PN/A.•About 75 % of COD and 70 % of P were recovered through sludge discharge.•Reduced costs and energy consumption with no additional reagents required.•Techno-economic assessment confirmed the feasibility of the process. In response to the escalating global water scarcity and the high energy consumption associated with traditional wastewater treatment plants, there is a growing demand for transformative wastewater treatment processes that promise greater efficiency and sustainability. This study presents an innovative approach for municipal wastewater treatment that integrates high-rate activated sludge with membrane bio-reactor (HRAS-MBR), reverse osmosis (RO) and partial nitrification-anammox (PN/A). With an influent of 8.4 m³/d, the HRAS-MBR demonstrated a removal efficiency of approximately 85 % for chemical oxygen demand (COD), with over 70 % of it being recovered for energy production. The RO system achieved a recovery rate of 75 % for the influent, producing pure water with an electrical conductivity of 50 μS/cm. Concurrently, it concentrated ammonia, thereby enhancing the effectiveness of the PN/A process for nitrogen removal in the mainstream, resulting in a removal efficiency exceeding 85 %. Notably, the HRAS-MBR achieved significant phosphorus removal without chemical additives, attributed to the presence of influent calcium and magnesium ions. Overall, this integrated system reduced the net energy consumption for reclaimed water production by about 26 % compared to conventional methods. Additionally, the new process produced a revenue of 0.75 CNY/m³, demonstrating considerable economic and environmental benefits. This pilot-scale study offers a viable alternative for wastewater treatment and water reuse in water-scarce regions, contributing to sustainable water resource management. [Display omitted]