nitrate is an anion of major importance particularly in biological areas. excessive amounts in water supplies indicate pollution from sewage or agricultural effluents. the effects of excessive quantities of nitrate in water are well known. in this research structural modification of natural clinoptilolite by isomorphic substitution was performed. isomorphously substituted zeolite was prepared u...

We report a novel method for measurement of the oxygen isotopic composition (18O/16O) of nitrate (NO3-) from both seawater and freshwater. The denitrifier method, based on the isotope ratio analysis of nitrous oxide generated from sample nitrate by cultured denitrifying bacteria, has been described elsewhere for its use in nitrogen isotope ratio (15N/14N) analysis of nitrate. (1) Here, we addre...

The nitrate-reducing bacterial strain BunN is able to grow with acetone and nitrate under anoxic conditions. Dialyzed crude cell-free extracts of acetone-plus-nitrate-grown cells of strain BunN catalyzed the exchange of 14CO2 into acetoacetate in an ADP-dependent reaction. The rates of exchange catalyzed by extracts of acetate-grown or 3-hydroxybutyrate-grown cells were only 13% of that catalyz...

Arsenate and nitrate can be removed quantitatively from drinking water by anion exchange. However, if the raw water contains substantial concentrations of sulfate or nitrate, the resin becomes exhausted quickly, and the requirements for regenerant (brine) can make the process unattractive. Previously, we described a modified ion exchange operating procedure for arsenic removal from solutions co...

Nitrogen (N) isotope ratios ((15)N/(14)N) provide integrative constraints on the N inventory of the modern ocean. Anaerobic ammonium oxidation (anammox), which converts ammonium and nitrite to dinitrogen gas (N2) and nitrate, is an important fixed N sink in marine ecosystems. We studied the so far unknown N isotope effects of anammox in batch culture experiments. Anammox preferentially removes ...

response of tea plants to b deficiency was studied in hydroponic medium under environmentally controlled conditions. plants height, number of leaves and dry matter production of shoot and root were significantly decreased by b deficiency. concentration of chlorophyll, carotenoids, anthocyanins and flavonoids was not affected by b deficiency in the young leaf, while a significant reduction of ch...

Objective: Very recent studies have reported positive effects of dietary nitrate on the oxygen consumption during exercise. This research aimed to study the effect of moderate dose of high-nitrate vegetables, watercress (Nasturtium officinale) and red radish (Raphanus sativus) compared with a control group on the incremental treadmill exercise test following a standard Bruce protocol controlled...

Abstraet--A laboratory study of cadmium exchangeability revealed large differences in extractable cadmium which are dependent on the exchange solution being utilized. The standard exchange solutions employed in this study were: N NaNO3, N NaOAc, N NH4OAc, NCaCI~, and 2N CaCI2, in order of increasing Cd removal. An interpretation of the chemical behavior of Cd and an experiment with mixed sodium...