THE present investigation is concerned with the oxidation of ammonium salts to nitric acid in soil. In Part I [Corbet, 1934] the chemical aspects of the subject were dealt with, and in this paper the reactions effected by bacterial agency are considered. For work on the biological oxidation of ammonia, aqueous solutions of ammonium sulphate containing small amounts of nutrient salts were inocul...

The sole energy-yielding reaction of the autotrophic nitrifying bacterium Nitrosomonas europaea involves the conversion of ammonium to nmtrite. As early as 1926, Kluyver and Donker postulated that the six electron oxidation proceeds with the intermediary formation of hydroxylamine and hyponitrous acid. Only recently have there been any studies of the biochemical mechanism of chemoautotrophic am...

We propose a model for the water-oxidation and recovery systems of the oxygen-evolving complex (OEC) of the photosystem II (PSII) enzyme. The whole system is constructed from two catalytic cycles, conducted as a tandem reaction: (i) a water-oxidation loop uses cerium(IV) ammonium nitrate as an oxidant to activate a dimanganese complex for water-oxidation and thereby liberate a molecule of O2 an...

Anaerobic ammonium oxidation (anammox) involves the microbiological oxidation of ammonium with nitrite as the electron acceptor and dinitrogen gas as the main product. The Scalindua species, an anammox genus that dominates natural habitats, plays an important role in catalysing the loss of nitrogen from marine environments. Until now, a few Scalindua species have been reported to be enriched fr...

In wastewater treatment plants with anaerobic sludge digestion, 15–20% of the nitrogen load is recirculated to the main stream with the return liquors from dewatering. Separate treatment of this ammonium-rich digester supernatant significantly reduces the nitrogen load of the activated sludge system. Two biological applications are considered for nitrogen elimination: (i) classical autotrophic ...

This study contributes to the improvement of low-cost biotechnology for wastewater treatment in constructed wetlands (CWs). Constructed wetlands are energy efficient engineered systems that mimic the treatment processes of natural wetlands, removing polluting organic matter, nutrients, and pathogens from water. The aim of this study was to investigate the advisability of the inoculation of hori...