Biological rapid sand filters are often used to remove ammonium from groundwater for drinking water supply. They often operate under dynamic substrate and hydraulic loading conditions, which can lead to increased levels of ammonium and nitrite in the effluent. To determine the maximum nitrification rates and safe operating windows of rapid sand filters, a pilot scale rapid sand filter was used ...

Abstract Ammonium-induced stimulatory, inhibitory, and/or neutral effects on soil methane oxidation have been attributable to the ammonium concentration and mineral forms, confounded by other edaphic properties (e.g., pH, salinity), as well site-specific composition of methanotrophic community. We hypothesize that this inconsistency may stem from discrepancy in cation adsorption capacity soil. ...

The photo catalytic oxidation of Surfactant Hexadecyltrimethyl-ammonium bromide in aqueous diluted solution has been investigated. Compressed air was used as oxidant and the temperature was maintained at 25-30°C. Effect of UV rays alone and in combination of hydrogen peroxide (H O ) and titanium 2 2 dioxide (TiO ) on Hexadecyltrimethyl-ammonium bromide (C H NBr) was recorded. Finally, from HPLC...

Biological oxidation of radiolabeled NH(4) (half-life = 10 min) was observed within minutes in assays of an estuarine ammonium oxidizer and in natural populations of nitrifiers in coastal waters. Our estimates of turnover of the ammonium pool and rates of nitrification based on experiments using N are consistent with previous values in the literature based on longer-term N tracer experiments or...

Monodisperse single-crystal hollow cerium dioxide nanocubes with exposed (001) facets have been synthesized with the assistance of ammonium chloride (NH4Cl) and polyvinylpyrrolidone (PVP) in a water and ethanol system. A series of experiments indicate that ammonium ion plays an important role in the formation of the hollow structure and PVP plays a key role in the formation of a cubic shape. Th...

The cold-adapted bacterium Pseudomonas putida Y-9 was investigated and exhibited excellent capability for nitrogen removal at 15°C. The strain capable of heterotrophic nitrification and aerobic denitrification could efficiently remove ammonium, nitrate, and nitrite at an average removal rate of 2.85 mg, 1.60 mg, and 1.83 mg NL-1 h-1, respectively. Strain Y-9 performed nitrification in preferenc...

Anaerobic ammonium oxidation (anammox) is a recently discovered microbial pathway and a cost-effective way to remove ammonium from wastewater. Anammox bacteria have been described as obligate chemolithoautotrophs. However, many chemolithoautotrophs (i.e., nitrifiers) can use organic compounds as a supplementary carbon source. In this study, the effect of organic compounds on anammox bacteria wa...