Insights into Nitrous Oxide Mitigation Strategies in Wastewater Treatment and Challenges for Wider Implementation

作者：Haoran Duan, Yingfen Zhao, Konrad Koch, George Wells, Min Zheng, Zhiguo Yuan, Liu Ye · 发表于：Environmental Science & Technology · 年份：2021 · DOI：10.1021/acs.est.1c00840 · 被引用次数：170 · 研究领域：Wastewater Treatment and Nitrogen Removal、Water Treatment and Disinfection、Constructed Wetlands for Wastewater Treatment

Nitrous oxide (N 2 O) emissions account for the majority of the carbon footprint of wastewater treatment plants (WWTPs). Many N 2 O mitigation strategies have since been developed while a holistic view is still missing. This article reviews the state-of-the-art of N 2 O mitigation studies in wastewater treatment. Through analyzing existing studies, this article presents the essential knowledge to guide N 2 O mitigations, and the logics behind mitigation strategies. In practice, mitigations are mainly carried out by aeration control, feed scheme optimization, and process optimization. Despite increasingly more studies, real implementation remains rare, which is a combined result of unclear climate change policies/incentives, as well as technical challenges. Five critical technical challenges, as well as opportunities, of N 2 O mitigations were identified. It is proposed that (i) quantification methods for overall N 2 O emissions and pathway contributions need improvement; (ii) a reliable while straightforward mathematical model is required to quantify benefits and compare mitigation strategies; (iii) tailored risk assessment needs to be conducted for WWTPs, in which more long-term full-scale trials of N 2 O mitigation are urgently needed to enable robust assessments of the resulting operational costs and impact on nutrient removal performance; (iv) current mitigation strategies focus on centralized WWTPs, more investigations are warranted for decentralised systems, especially ...