Nitrite

About: Nitrite is a research topic. Over the lifetime, 15425 publications have been published within this topic receiving 484581 citations.

Sources and reactions of OH and daughter radicals in seawater

Abstract: Nitrate and nitrite ions are destroyed by solar photolysis. Rate estimates for these processes in tropical surface waters imply relatively rapid reaction of both ions and yield minimum production rates for the reactive products. Products include the free radicals NO, NO2, and O−; at pH 8, O− yields OH radical. If NO is converted to nitrite by dark reactions, the nitrite reactions sum to a photocatalyzed conversion of dissolved oxygen and water to OH radicals. Kinetic calculations and flash photolysis experiments both indicate that in seawater, OH reacts rapidly and semiquantitatively with bromide to yield dissolved bromine atoms, which complex with halide ions. Subsequent reactions of potential geochemical significance include recombinations, heavy metal redox processes, and selective oxidation of organic matter. These processes may affect marine aerosols as well as surface seawater.

Ammonium sorption and ammonia inhibition of nitrite-oxidizing bacteria explain contrasting soil N2O production.

Abstract: Ammonium sorption and ammonia inhibition of nitrite-oxidizing bacteria explain contrasting soil N 2 O production

Nitrate and nitrite hydrogenation with Pd and Pt/SnO2 catalysts: the effect of the support porosity and the role of carbon dioxide in the control of selectivity

Abstract: The preparation of some new Pd and Pt catalysts dispersed on SnO 2 prepared in different ways is reported. Supports differ in surface area and porosity. Samples are characterized by BET, TPR and powder XRD analysis. The hydrogenation of 100 ppm nitrate and nitrite solutions shows significant differences depending on the nature of the metal (Pd catalysts are much better than Pt) and the morphology of the support. The selectivity to nitrogen benefits from the use of low surface area, large pore supports. The use of CO 2 in the gas feed is analyzed and the role of carbon dioxide as a buffer is demonstrated by comparison with acetate buffer. The results suggest the importance of intraparticle diffusion and local buffering in the control of the activity and selectivity of the reaction.

Effect of nitrate and nitrite on the selection of microorganisms in the denitrifying anaerobic methane oxidation process.

Abstract: P>Two cultures were inoculated with sludges taken from a parent culture containing archaea distantly related to anaerobic methanotrophic archaea (ANME) and bacteria related to Candidatus Methylomirabilis oxyfera, both of which have previously been found in cultures performing denitrifying anaerobic methane oxidation process. The cultures were fed with nitrate and nitrite, respectively, along with methane. The nitrate-fed culture, Culture B, showed a stable microbial community composition and denitrifying anaerobic methane oxidation activity. In contrast, the nitrite-fed culture, Culture A, achieved a substantial increase in the nitrite consumption rate, from 1.1 to 7.3 mmol NO(2)--N (g VSS)-1 day-1 in 90 days. Concurrent with this activity increase, the archaeal population in Culture A decreased with time, and became undetectable after 100 days, while bacteria related to M. oxyfera increasingly dominated the culture. This observation suggests that the bacteria related to M. oxyfera are more competitive for nitrite reduction compared with the archaea related to ANME. This study showed that nitrate or nitrite feeding has a significant impact on the ecology and activities of microorganisms in the denitrifying anaerobic methane oxidation process. This study also revealed that nitrite overloading may have a toxic effect on the bacteria related to M. oxyfera.