The physiology of anaerobic ammonium oxidizing (anammox) aggregates grown in a sequencing batch reactor was investigated quantitatively. The physiological pH and temperature ranges were 6.7 to 8.3 and 20 to 43 degrees C, respectively. The affinity constants for the substrates ammonium and nitrite were each less than 0.1 mg of nitrogen per liter. The anammox process was completely inhibited by n...

ANaerobic AMMonium OXidation (Anammox) is an efficient microbiological process for the removal of ammonia nitrogen from wastewater. Although several Anammox reactors have been operated successfully in European water pollution control plants, there are challenges associated with the process which must be addressed to ensure dependable performance when treating high strength wastestreams in New Y...

The electrochemical oxidation of the digested effluent from anaerobic digestion of dairy manure was investigated in this study. The digested effluent sample containing with suspended solids was pretreated by filtration for the electrochemical experiment. The influence of direct anodic oxidation and indirect oxidation was evaluated through the use of dimensionally stable anode (DSA) and Ti/PbO2 ...

This study investigated the influence of dissolved oxygen concentration and aeration time on nitrification and nitrite accumulation in an attempt to optimize the recently developed biological-partial-nitritation process for the treatment of strong nitrogen wastewaters. Investigation of dissolved oxygen concentration on ammonium and nitrite oxidation was carried out in a batch reactor. The disso...

A chemolithotrophic ammonium-oxidizing bacterium that was able to reduce NO(2) to N(2) (m/z 30) while oxidizing ammonium under conditions of oxygen stress was isolated from stream sediments. Energy was derived from ammonium oxidation, as evidence by growth, with CO(2) serving as the sole C source. The organism was a gram-negative, motile, short rod that failed to grow either aerobically or anae...

It has been less than two decades since anammox (anaerobic ammonium oxidation) coupled to nitrite reduction has been discovered. Already, this process has been recognized as an important sink for fixed nitrogen in the natural environment and has been implemented as a cost-effective ammonium removal technology. Still, little is known about the molecular mechanism of this remarkable reaction. In ...

Ammonia oxidation in laboratory liquid batch cultures of autotrophic ammonia oxidizers rarely occurs at pH values less than 7, due to ionization of ammonia and the requirement for ammonium transport rather than diffusion of ammonia. Nevertheless, there is strong evidence for autotrophic nitrification in acid soils, which may be carried out by ammonia oxidizers capable of using urea as a source ...