Enhancement of Anaerobic Ammonium Oxidation (Anammox) Process: The use of one-pot synthesized nanoscale zero-valent iron (nZVI)

Anammox process, which is a proven technology for sidestream nitrogen removal, still has a few challenges for mainstream applications in STPs. Different strategies are under evaluation in order to make it applicable for mainstream. One of the strategy that may be implemented is to use of zero-valent iron (ZVI) to enhance the activity of Anammox bacteria. This study aimed to evaluate the effect of ZVI on nitrogen removal and granulation performance of Anammox process. The focus was on nano-scale ZVI (nZVI) instead of its microsized counterpart due to its various benefits. An SBR system was operated for 234 days at various nZVI levels (0.04-500 ppb) and was followed by daily and instant NH4+-N and NO2--N removal rates, instant N2 gas production rates, qPCR analyses, EPS protein analyses and STEM images. The findings demonstrated the net positive effect of nZVI both on Anammox process efficiency and granulation of Anammox species.