Comparison of Anoxic Ammonia Removal Using Granulated Nanostructured Oxyhydroxides of Fe with Seed Biomass From Different Eco-System

Abstract

Removal of ammonium in anoxic conditions with the aid of granulated nanostructured oxyhydroxides of Fe(GNOF) was investigated in sequential batch reactors for biomass with different eco-systems as the source.GNOF was synthesized using a simple template-assisted one-pot technique. The removal of NH₄⁺ occurs via a unique short-circuited pathway mediated by a mixed culture of microbes that involves oxidation of ammonium which is coupled to the reduction of Fe3+ along with the formation of N2, NO2 - , and NO3 - . Further, the reduced Fe2+ is oxidized back to Fe3+and hence reducing the amount of GNOF needed to be added to the reactors to ensure the process sustenance. Anoxic removal of NH₄⁺ was confirmed from the Enrichment of culture results for 86 days using both aerobic and anaerobic sludge to draw a comparison among the two for their potential to serve as seed biomass. The percentage of removal of NH₄⁺ was observed to be 94.65% and 95.07% for aerobic and anaerobic sludge, respectively, indicating both the seed sludges could be used for developing the process. This process is advantageous over the conventional techniques used for NH₄⁺ removal as it is more environmentfriendly and economical as less sludge needs to be handled and no aeration is required.