Search results
Results from the WOW.Com Content Network
Dissimilatory nitrate reduction to ammonium is a two step process, reducing NO 3 − to NO 2 − then NO 2 − to NH 4 +, though the reaction may begin with NO 2 − directly. [1] Each step is mediated by a different enzyme, the first step of dissimilatory nitrate reduction to ammonium is usually mediated by a periplasmic nitrate reductase.
Nitrification is important in agricultural systems, where fertilizer is often applied as ammonia. Conversion of this ammonia to nitrate increases nitrogen leaching because nitrate is more water-soluble than ammonia. Nitrification also plays an important role in the removal of nitrogen from municipal wastewater.
The amount of ammonium in the ocean is about 3 orders of magnitude less than nitrate. [42] Between ammonium, nitrite, and nitrate, nitrite has the fastest turnover rate. It can be produced during nitrate assimilation, nitrification, and denitrification; however, it is immediately consumed again.
A maximum ammonium removal rate of 0.4 kg N/m 3 /d was achieved. It was shown that for every mole of ammonium consumed, 0.6 mol of nitrate was required, resulting in the formation of 0.8 mol of N 2 gas. In 1995, the biological nature of anammox was identified. [27] Labeling experiments with 15 NH + 4 in combination with 14 NO − 3 showed that ...
Ammonium nitrate is an important fertilizer with NPK rating 34-0-0 (34% nitrogen). [17] It is less concentrated than urea (46-0-0), giving ammonium nitrate a slight transportation disadvantage. Ammonium nitrate's advantage over urea is that it is more stable and does not rapidly lose nitrogen to the atmosphere.
Oxygen likely affects denitrification in multiple ways—because most denitrifiers are facultative, oxygen can inhibit rates, but it can also stimulate denitrification by facilitating nitrification and the production of nitrate. In wetlands as well as deserts, [21] moisture is an environmental limitation to rates of denitrification.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Nitrogen-15 (15 N) tracing is a technique to study the nitrogen cycle using the heavier, stable nitrogen isotope 15 N.Despite the different weights, 15 N is involved in the same chemical reactions as the more abundant 14 N and is therefore used to trace and quantify conversions of one nitrogen compound to another.