Path to zero emission of nitrous oxide in sewage treatment: is nitrification controllable or avoidable?
Min Zheng, James Lloyd, Peter Wardrop, Haoran Duan, Tao Liu, Ye Liu, Bing‐Jie Ni
Abstract
Amid growing concerns over climate change, the need to reduce nitrous oxide (N 2 O) emissions from sewage treatment is more urgent than ever. Sewage treatment plants are significant sources of N 2 O due to its production as an intermediate in nitrification and its release into the air during aeration. Effective management of the nitrification process is therefore vital for controlling or eliminating these emissions. Despite substantial efforts to quantify and understand N 2 O emissions from sewage treatment, success in reducing them has been limited. This review discusses and proposes promising solutions for reducing N 2 O emissions in sewage treatment, evaluates the potential of various strategies, and identifies ways to accelerate their development and implementation. • Nitrification unit is a hot spot of N 2 O emissions in current sewage treatment plants. • Controllable nitrification shows promise for mitigation of N 2 O emissions. • Avoiding nitrification is feasible through the development of new NH 4 + management strategies. • End-of-pipe techniques for off-gas treatment remain critical to achieving zero N 2 O emissions.