As an efficient method for ammonium (NH4+) removal, contact catalytic oxidation technology has drawn much attention recently, due to its good low temperature resistance and short start-up period. Two identical filters were employed to compare the process for ammonium removal during the start-up period for ammonium removal in groundwater (Filter-N) and surface water (Filter-S) treatment. Two typ...

Marine Crenarchaeota are the most abundant single group of prokaryotes in the ocean, but their physiology and role in marine biogeochemical cycles are unknown. Recently, a member of this clade was isolated from a sea aquarium and shown to be capable of nitrification, tentatively suggesting that Crenarchaeota may play a role in the oceanic nitrogen cycle. We enriched a crenarchaeote from North S...

Starved cells of Nitrosomonas europaea and further ammonia oxidizers were able to rapidly accumulate ammonium and hydroxylamine to an internal concentration of about 1 and 0.8 M, respectively. In kinetic studies, the uptake/accumulation rates for ammonium [3.1 mmol (g protein)(-1) min(-1)] and hydroxylamine [4.39 mmol (g protein)(-1) min(-1)] were determined. The uptake and accumulation process...

A flow biosensor for the detection of toxicity in water using the ammonia-oxidizing bacterium (AOB) Nitrosomonas europaea as a bioreceptor and a polymeric membrane ammonium-selective electrode as a transducer is described. The system is based on the inhibition effects of toxicants on the activity of AOB, which can be evaluated by measuring the ammonium consumption rates with the ammonium-select...

This paper describes the experiments carried out to analyse total dissolved N involving UV oxidation and high temperature catalytic oxidation (HTCO) methods. Standards of known N concentrations (i.e. ammonium and EDTA) irradiated with UV oxidation for 6 h were found to show good oxidation efficiency (72-107%). However, poor recovery was recorded for urea (2-20%). The addition of reaction initia...

Rhizobium sp. strain ORS571 conducts synergistic, free-living N2 fixation and nicotinate oxidation. Explicitly, ORS571 is able to fix N2 aerobically because 6-OH-nicotinate acts as an intracellular O2 sink. Because 6-OH-nicotinate oxidation is mandatory for aerobic, free-living N2 fixation and because the synergistic processes yield ammonium from substrates (as the nitrogen source for growth), ...

In this study, the membrane biofilm reactor (MBfR) is proposed to achieve simultaneous removal of ammonium, dissolved methane, and sulfide from main-stream and side-stream anaerobic digestion liquors. To avoid dissolved methane stripping, oxygen is introduced through gas-permeable membranes, which also from the substratum for the growth of a biofilm likely comprising ammonium oxidizing bacteria...

Anaerobic ammonium oxidation with an anode as the electron acceptor was realized in a dual-chamber microbial electrolysis cell (MEC). Nitrate was the main product that accounted for approximately 95% of ammonium consumed, but nitrite was also detectable. Using 16S ribosomal RNA analysis, we found that the microbial community attached to the electrode was dominated by Nitrosomonas europaea (40.3...