Inhibition of anammox activity by municipal and industrial wastewater pollutants: A review

• Published in: The Science of the total environment Vol. 799; p. 149449
• Main Authors: Madeira, Camila Leite, de Araújo, Juliana Calábria
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10-12-2021
• Subjects: Anammox; Inhibition; Pollutants; Toxicity; Wastewater; Anammox; Inhibition; Pollutants; Wastewater; Toxicity
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2021.149449

The use of the anammox process for nitrogen removal has gained popularity across the world due to its low energy consumption and waste generation. Anammox reactors have been used to treat ammonium-rich effluents such as chemical, pharmaceutical, semiconductor, livestock, and coke oven wastewater. Recently, full-scale installations have been implemented for municipal wastewater treatment. The efficiency of biological processes is susceptible to inhibitory effects of pollutants present in wastewater. Considering the increasing number of emerging contaminants detected in wastewater, the impacts of the different types of pollutants on anammox bacteria must be understood. This review presents a compilation of the studies assessing the inhibitory effects of different wastewater pollutants towards anammox activity. The pollutants were classified as antibiotics, aromatics, azoles, surfactants, microplastics, organic solvents, humic substances, biodegradable organic matter, or metals and metallic nanoparticles. The interactions between the pollutants and anammox bacteria have been described, as well as the interactions between different pollutants leading to synergistic effects. We also reviewed the effects of pollutants on distinct species of anammox bacteria, and the main toxicity mechanisms leading to irreversible loss of anammox activity have been identified. Finally, we provided an analysis of strategies to overcome the inhibitory effects of wastewater pollutants on the nitrogen removal performance. We believe this review will contribute with essential information to assist the operation and design of anammox reactors treating different types of wastewaters.
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•We reviewed 94 papers regarding inhibition of anammox bacteria by pollutants.•The inhibitory effects of several types of wastewater pollutants were reported.•Pollutants exert inhibition according to properties such as solubility, hydrophobicity, and charge.•Extracellular polymeric substances protect anammox cells against toxic loads.•Acclimatization, bioaugmentation, and C/N control were presented as strategies to enhance anammox performance.