Guangdong Basic Research Center of Excellence for Ecological Security and Green Development, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou, 510006, China; Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou, 510006, China.
Department of Ecological Sciences and Engineering, Chongqing University, Chongqing, 400045, China.
Environ Res. 2024 Nov 1;260:119591. doi: 10.1016/j.envres.2024.119591. Epub 2024 Jul 11.
Reducing NO emissions is key to controlling greenhouse gases (GHG) in wastewater treatment plants (WWTPs). Although studies have examined the effects of dissolved oxygen (DO) on NO emissions during nitrogen removal, the precise effects of aeration rate remain unclear. This study aimed to fill this research gap by investigating the influence of dynamic aeration rates on NO emissions in an alternating anoxic-oxic sequencing batch reactor system. The emergence of DO breakthrough points indicated that the conversion of ammonia nitrogen to nitrite and the release of NO were nearly complete. Approximately 91.73 ± 3.35% of NO was released between the start of aeration and the DO breakthrough point. Compared to a fixed aeration rate, dynamically adjusting the aeration rates could reduce NO production by up to 48.6%. Structural equation modeling revealed that aeration rate and total nitrogen directly or indirectly had significant effects on the NO production. A novel regression model was developed to estimate NO production based on energy consumption (aeration flux), water quality (total nitrogen), and GHG emissions (NO). This study emphasizes the potential of optimizing aeration strategies in WWTPs to significantly reduce GHG and improve environmental sustainability.
减少氮氧化物（NO）排放是控制污水处理厂（WWTP）温室气体（GHG）的关键。尽管已有研究考察了溶解氧（DO）对脱氮过程中 NO 排放的影响，但曝气速率的精确影响仍不清楚。本研究旨在通过考察动态曝气速率对交替缺氧-好氧序批式反应器系统中 NO 排放的影响来填补这一研究空白。DO 突破点的出现表明氨氮向亚硝酸盐的转化和 NO 的释放几乎完全完成。在曝气开始和 DO 突破点之间，约有 91.73±3.35%的 NO 被释放。与固定曝气速率相比，动态调整曝气速率最多可减少 48.6%的 NO 生成。结构方程模型表明，曝气速率和总氮直接或间接对 NO 生成有显著影响。开发了一种新的回归模型，根据能耗（曝气通量）、水质（总氮）和 GHG 排放（NO）来估算 NO 生成。本研究强调了优化 WWTP 曝气策略以显著减少 GHG 和提高环境可持续性的潜力。
