The effects of different concentrations of CdCl2 and AlCl3 on NH4+ and NO2? oxidation in an aqueous system were investigated. AlCl3 had no effect on NH4+ removal and its oxidation to NO2?, whereas NO2? disappearance was greatly enhanced by AlCl3. In contrast, CdCl2 delayed removal of NH4+ and its subsequent oxidation to NO2? and also decreased the rate of NO2? disappearance. When compared to th...

From extraction experiments and gamma-activity measurements, the extraction constan corresponding to the equilibrium NH4(+)(aq) + 1*Na(+)(nb) <=> 1*NH4(+)(nb) + Na(+)(aq) taking place in the two-phase water - nitrobenzene system (1 = dibenzo-18-crown-6, aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K(ex) (NH4(+),1*Na(+)) = -0.1 +/- 0.1. Further, the stability constant of the...

NH4 uptake capacity of loblolly pine (Pinus taeda L.) and ponderosa pine (Pinus ponderosa Douglas. Ex Laws.) seedlings that were grown in pots in a phytotron at CO2 partial pressures of 35 or 70 Pa with NH4 + as the sole N source. Kinetics of N-labeled NH4 + uptake were determined in excised roots, whereas total NH4 + uptake and uptake rates were determined in intact root systems following a 48...

Two types of ammonium uranyl nitrate (NH4)2UO2(NO3)4·2H2O and NH4UO2(NO3)3, were thermally decomposed and reduced in a TG-DTA unit in nitrogen, air, and hydrogen atmospheres. Various intermediate phases produced by the thermal decomposition and reduction process were investigated by an X-ray diffraction analysis and a TG/DTA analysis. Both (NH4)2UO2(NO3)4·2H2O and NH4UO2(NO3)3 decomposed to amo...

In this study we characterized ammonia and ammonium (NH3/NH4(+)) transport by the rhesus-associated (Rh) glycoproteins RhAG, Rhbg, and Rhcg expressed in Xenopus oocytes. We used ion-selective microelectrodes and two-electrode voltage clamp to measure changes in intracellular pH, surface pH, and whole cell currents induced by NH3/NH4(+) and methyl amine/ammonium (MA/MA(+)). These measurements al...

The responses of macroalgae to ocean acidification could be altered by availability of macronutrients, such as ammonium (NH4+). This study determined how the opportunistic macroalga, Ulva australis responded to simultaneous changes in decreasing pH and NH4+ enrichment. This was investigated in a week-long growth experiment across a range of predicted future pHs with ambient and enriched NH4+ tr...

A significant amount of ammonium (NH4+) is absorbed by the colon. The nature of NH4+ effects on transport and NH4+ transport itself in colonic epithelium is poorly understood. The goal of this study was to elucidate the effects of NH4+ on cAMP-stimulated Cl- secretion in the colonic cell line T84. In HEPES-buffered solutions, application of basolateral NH4+ resulted in a reduced level of Cl- se...

The objective of this study was to evaluate the treatment efficiency of a gravel contact oxidation treatment system which was newly constructed under the riverbed of Nan-men Stream located at the Shin Chu City of Taiwan. The influent and effluent water samples were taken periodically for the analyses of pH, temperature, dissolved oxygen, total suspended solids, five-day biological oxygen demand...