Critical review on insight into the impacts of different inhibitors and performance inhibition of anammox process with control strategies

Anaerobic ammonium oxidation is low-energy consuming biological and environment friendly process to treat wastewaters rich in nitrogen content. However, many factors are responsible for inhibition of anammox route that prevent advances and efficiency of the process. Many inhibitory substances influence the effectiveness of the process including substrates (nitrite and ammonia), heavy metals, organic matter, phosphates, sulfides and salts concentrations in applications. This review paper is conducted based on prior studies on the inhibitory conditions affecting efficiency of anammox process. The effect of these inhibitors differs widely owing to varied operational requirements, methodologies, physical properties of sludge and presence of microbial populations in sludge. The optimum pH, temperature, dissolved oxygen, substrate concentration, sludge acclimatization, oxidation-reduction potential, use of supporting agents and load controls can significantly improve efficiency during inhibitory environments. The knowledge of various inhibitory factors on anammox will help prevent the application and improvement of anammox process. (C) 2021 Elsevier B.V. All rights reserved.