Nitrogen metabolism of planktonic populations in coastal waters of the southern Scotia Sea was studied in February-March 1981 aboard R/V M e l d l e . In spite of the high concentration of nitrate present in these waters (21 to 29 FM), up to 93 % of phytoplankton nitrogen was assimilated in the form of ammonium, with the overall mean being 78 %. Time course experiments showed that uptake of nit...

The article studies the process of obtaining carbonate-ammonium nitrate (CAN) based on mixing melt ammonium (NH4NO3) with chalk (СаСО3) and sulfate (NH4)2SO4). For granulation nitrate-sulfate-carbonate prilling method is applied using a tower. Determined composition properties new types fertilizers. It shown that ratio NH4NO3 : СаСО3 (NH4)2SO4 = 100 24 1 product contains 28,03% N, SO3 – 0,50%, ...

Nitrate utilization and ammonium utilization were studied by using three algal isolates, six bacterial isolates, and a range of temperatures in chemostat and batch cultures. We quantified affinities for both substrates by determining specific affinities (specific affinity = maximum growth rate/half-saturation constant) based on estimates of kinetic parameters obtained from chemostat experiments...

Several lines of evidence implicate ammonium as an important factor in the growth and development of cotton (Gossypium hirsutum L.) ovules cultured in vitro. For example, ovules cultured at 28 C require indoleacetic acid (IAA) and either ammonium or gibberellic acid (GA(3)) in the medium for fiber development, whereas ovules cultured at 34 C require only IAA. Because of this effect of ammonium ...

-Existing methods of measuring atmospheric aerosol strong acidity adequately prevent neutralization of fine-particle acidity by removing coarse alkaline particles and gaseous ammonia from air samples. However, these techniques do not consider particle interactions on the collection medium; therefore, they may still underestimate the actual aerosol acidity. Assessment of acid neutralization due ...

The removal of excess nutrients from water ecosystems requires oxidation of toxic ammonium by two types of bacteria; one oxidizes ammonium to nitrite and the other oxidizes nitrite to nitrate. The oxidation of ammonium is often incomplete and nitrite accumulates. Nitrite is also toxic, and is converted by the ammoniumoxidizing bacteria to nitrous oxide, a powerful greenhouse gas. Here we use ma...

A basic investigation on the removal of Cu(II) and Ni(II) ions from metal solution by crosslinked chitosan-g-acrylonitrile copolymer was conducted in a batch adsorption system. Graft copolymers of crosslinked chitosan (CLCS) with acrylonitrile (AN) were prepared by free radical polymerization using initiator ceric ammonium nitrate as redox system. Graft copolymerization was confirmed by FTIR, X...

ABSTRACT CeO2 was synthesized by combined sol-gel and solvothermal processing of gels obtained from acetaldoximate-modified cerium(IV) t-butoxide in the presence of the non-ionic surfactant Pluronic F127. The use of cerium(IV) t-butoxide as precursor contrasts very favorably with the often used ceric ammonium nitrate and results in more reliable and tailorable properties of the final materials....