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Ammonium Oxide - Wiley Online Library

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Last Updated: 16 April 2022

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Seasonal dynamics of anaerobic oxidation of ammonium and denitrification in a dimictic lake during the stratified spring–summer period

To determine the predominant nitrogen conversion processes at lake Fohnsee during the spring and summer seasons, concentration profiles and stable isotope compositions of NO3 and NH4+ were used, as well as numerical modeling and quantification of the hydrazine synthase gene and nitrite reductase genes. This shift in 15N+NH4+ is mainly controlled by mixing between ammonium stemming from the oxic water column with 15N values of 25 and ammonium that is likely formed in the lake sediments by oxidation of organic matter with a 15N value of 11. The presence of nitrate reduction and low rates of anammox in lake water samples collected in June and July confirmed co-occurrence of nitrate reduction and low rates of anammox, according to the authors, although the presence of sulfide in August and September may have reduced the activity of anammox bacteria near the lake bottom's sulfate-reduction zone.

Source link: https://onlinelibrary.wiley.com/doi/10.1002/lno.12067


2‐(N‐3‐Sulfopropyl‐N,N‐dimethyl ammonium)ethyl methacrylate modified graphene oxide embedded into cellulose acetate ultrafiltration membranes for improved performance

The effect of different GO and PSBMA@GO contents on cellulose acetate membranes was investigated using AFM, contact angle measurements, and SEM methods. Through the water contact angle technique, the surface hydrophilicity of the fabricated membranes increased with increasing amounts of PSBMA@GO filler. At 900 kPa, the relative flux of the base membrane was 66. 6 L. m. -2. h. 1 relative to that of the PSBMA@GO composite membrane at 117. 67 L. m. 2. h. 1. In addition, nanocomposite membranes gave higher dye rejections for Congo Red, methyl orange, and methylene blue dyes when compared to unmodified CA membranes.

Source link: https://onlinelibrary.wiley.com/doi/10.1002/app.52336


The kinetics of ammonium uptake and oxidation across the Southern Ocean

The seasonal transition between nutrients up mixing and their subsequent consumption by phytoplankton is crucial to the Southern Ocean's role in setting atmospheric CO2. kinetics experiments were carried out across the Southern Ocean south of Africa to determine the connection of NH4+ uptake and oxidation on NH4+ concentrations. Although winter areas typically have a higher NH4+ supply, the half-saturation constant rose poleward with rising ambient NH4+ and was threefold higher in winter than in summer, suggesting that summertime phytoplankton are adapted to lower NH4+ conditions. A high affinity for NH4+ oxidation, suggesting a primary role for ammoniaoxidizing archaea, appeared in ammonia,oxidizing archaea, and followed a Michaelis-Menten curve only when [NH4+]amb was 90 nM. We hypothesize that iron availability may reduce the Vmax of NH4+ oxidation from coincident mixed layer oxidation and iron measurements.

Source link: https://onlinelibrary.wiley.com/doi/10.1002/lno.12050


The alleviation of manganese toxicity by ammonium in sugarcane is related to pectin content, pectin methyl esterification, and nitric oxide

Abstract: The presence of ammonium with manganese in acid soils may help reduce Mn toxicity to plants. Compared to NO3+, NH4+ improved Mn-induced chlorosis in sugarcane seedlings and increased seedling biomass in comparison to NO3+. However, the degree of root pectin esterification increased with the exogenous use of NH4+, but not at a point of root cell wall pectin content and methyl esterase activity. These treatments reduced the difference in the pectin Mn content between NH4+-fed and NO3-fed sugarcane, as did a similar treatment with the nitrate reductase inhibitor tungstate, which reduced root cell wall pectin content and NO accumulation. These results show that NH4+ can reduce Mn toxicity in sugarcane by reducing root pectin formation and root cell wall PME production, lowering cell wall PMD and decreasing both Mn and Mn binding capacity, and decreasing both Mn and Mn accumulation in response to different forms of nitrogen, and NO mediates the accumulation of both pectin and Mn.

Source link: https://onlinelibrary.wiley.com/doi/10.1111/gcbb.12936


A review on new ammonium oxidation alternatives for effective nitrogen removal from wastewater

Ammonium is rapidly reduced by other reducing agents as a highly oxidizing ion. NH4+ oxidation, Fe3+, SO426, and Mn4+ reduction have all been reported, and several studies have shown that they have collaborated in removing NH4+. This report examines the latest advancements in these processes, focusing on these latest NH4+ oxidation alternatives. The results show that the practical engineering applications for NH4+ removal are not suitable due to the harsh reaction conditions and low removal rates.

Source link: https://onlinelibrary.wiley.com/doi/10.1002/jctb.7028


Quantitatively evaluating activity and number of catalytic sites on metal oxide for ammonium perchlorate decomposition

Metal oxide catalytic degradation by metal oxides is complicated, and there is currently no established quantitative test technique to determine intrinsic catalytic activity. A new way to quantitatively assess metal oxides' catalytic capability for AP decomposition has been suggested here. Rod'like 00Fe2O3 has the highest catalytic activity in AP decomposition with the lowest THTD* of 345. 1°C and highest T* of 0. 544, which indicate the largest number and highest number of catalytic sites in the world.

Source link: https://onlinelibrary.wiley.com/doi/10.1002/aic.17582

* Please keep in mind that all text is summarized by machine, we do not bear any responsibility, and you should always check original source before taking any actions

* Please keep in mind that all text is summarized by machine, we do not bear any responsibility, and you should always check original source before taking any actions