Recent advances regarding the impacts of engineered nanomaterials on the anaerobic ammonium oxidation process: performances and mechanisms

Abstract

The development and application of anammox-based nitrogen removal technology is thought to have the potential to boost the evolution of wastewater treatment to a more sustainable model. However, due to the long doubling time and vulnerability to the varying operating conditions of anammox bacteria, the actual application of this technology remains restrained. Nanomaterials have been proposed as external suppliers to stimulate the activity of anammox bacteria. To date, although there are lots of experimental results, the actual effects relating to different types of nanomaterials still remain unclear. Moreover, besides artificially added nanoparticles, anammox may be inhibited by nanomaterials released during the use of nanotechnology products. Addressing the above challenges requires a better understanding of the performance, fate, and mechanism of interaction between various nanomaterials and anammox bacteria. Herein, this review describes the effects of various engineered nanomaterials on the nitrogen removal performance and metabolic properties of anammox bacteria. Also, the intoxication routes of nanomaterials and the detoxification mechanisms of anammox are analyzed and discussed. Finally, future development trends and research directions in this field are proposed.