جستجوی مقالات مرتبط با کلیدواژه « آمونیاک » در نشریات گروه « شیمی »

In this research, an efficient procedure is reported for the synthesis of aryl amines from aryl halides using aqueous ammonia in the presence of melamine-supported CuO nanocatalyst (M-CuO-nanocatalyst) in water. The catalyst was prepared by co-precipitation method and characterized by various techniques such as SEM, EDS, TGA, XRD , XRF, and BET analysis.Various aryl halides reacted with aqueous ammonia and corresponding aryl amines were obtained in relatively short reaction times and high yields. M-CuO-nanocatalyst is a stable, safe and high performance catalyst that working with it is easy. It can be easily separated from the reaction medium. M-CuO nanocatalyst is easily prepared, easy to handle and recyclable and up to 6 consecutive runs catalyzes the synthesis of aryl amines well. It could be reused more than 6 times without considerable loss of its initial activity. Furthermore, heterogeneous reaction conditions, clean procedure, simple work-up, high yields of products and short reaction times are other advantages of this method.

Luminescent graphene oxide quantum dots have attracted tremendous attention from the scientists in chemistry, materials science, physics and biology, because of their superiority of good stability, excellent optical and electrochemical properties, resistance to photo-bleaching, and low cytotoxicity. In the research, Graphene oxide quantum dot were synthesized using a simple and direct method. In the following, to increase and change the luminescence, graphene oxide doped with nitrogen N and sulfur S in a single step in the presence of thiourea and ammonia were synthesized. the graphene oxide quantum dots were characterized by infrared, UV–Vis absorption, photoluminescence spectroscopy, and TEM microscopy. S and N doped graphene oxide quantum dots, unlike the base graphene oxide quantum dots, have a blue luminescence and higher intensity than their base counterpart. Because of this prominent luminescence feature, N and S doped graphene oxide quantum dots can be used for medical imaging and other optical applications.

Treatment of toxic nitrogen-containing compounds is one of the major applications of the Wet Air Oxidation (WAO) processes. The objective of this study is determining the efficiency of wet air oxidation process to remove ammonia from leachate in Esfahan Composing factory. Aqueous wastes containing organic pollutants can be efficiently treated by wet air oxidation, i.e. oxidation by molecular oxygen in the liquid phase, under high temperature (100–300°C) and pressure (up to 10 bars).The results indicate that removal efficiency of NH3 at temperature 300° C and retention time 30 min 54.6 percent and the efficiency of nitrate produced 58.9 %, after 30 min reaction at 300 °C, 10 bars. In these conditions, the highest removal efficiency of ammonia and highest Amount of nitrate are produced. The average of NO3 production in this process is 32.5-58.9%. With further increasing temperature decomposition of organic material taken will be produced more ammonium. Also with increasing temperature and decreased retention time, ammonia oxidation to nitrate increased and nitrate are more produced.The WAO was an effective pre-treatment method for industrial wastewater and leachate with high amount of ammonia levels.