Topic
Ammonia
About: Ammonia is a research topic. Over the lifetime, 16217 publications have been published within this topic receiving 271940 citations. The topic is also known as: NH3 & azane.
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TL;DR: The effect of temperature on production of ammonia during dry anaerobic fermentation of chicken manure (CM), inoculated with thermophilic methanogenic sludge, was investigated in a batch condition for 8 days and a great improvement in the production of methane was achieved.
Abstract: The effect of temperature on production of ammonia during dry anaerobic fermentation of chicken manure (CM), inoculated with thermophilic methanogenic sludge, was investigated in a batch condition for 8 days. Incubation temperature did not have a significant effect on the production of ammonia. Almost complete inhibition of production of methane occurred at 55 and 65°C while quite low yields of 8.45 and 6.34 ml g−1 VS (volatile solids) were observed at 35 and 45°C due to a higher accumulation of ammonia. In order to improve the production of methane during dry anaerobic digestion of CM, stripping of ammonia was performed firstly on the CM previously fermented at 65°C for 8 days: the stripping for 1 day at 85°C and pH 10 removed 85.5% of ammonia. The first-batch fermentation of methane for 75 days was conducted next, using the ammonia-stripped CM inoculated with methanogenic sludge at different ratios, (CM: thermophilic sludge) of 1:2, 1:1, and 2:1 on volume per volume basis at both 35 and 55°C. Production of methane improved and was higher than that of the control (without stripping of ammonia) but the yield of 20.4 ml g−1 VS was still low, so second stripping of ammonia was conducted, which resulted in 74.7% removal of ammonia. A great improvement in the production of methane of 103.5 ml g−1 VS was achieved during the second batch for 55 days.
73 citations
TL;DR: It is concluded that Lahontan cutthroat trout, adapted to pH 9.4 water, maintain N-waste excretion by modifying mechanisms common to other teleosts, which facilitate the diffusive excretion of NH3 across the gills, and a lack of dependence of ammonia excretion on Na+ influx.
Abstract: Earlier studies have reported that acute exposure to alkaline pH strongly inhibits ammonia excretion in freshwater rainbow trout, but the Lahontan cutthroat trout thrives in Pyramid Lake, Nevada, at pH 9.4. We investigated the rates and mechanisms of ammonia and urea excretion in this species in Pyramid Lake water to determine whether special strategies are employed to excrete nitrogenous wastes in an environment unfavourable for ammonia excretion. The majority of nitrogen wastes (N-wastes) were excreted as ammonia (56 % through the gills, 10 % through the kidney), while urea excretion accounted for 34 % (32 % gills, 2 % kidney). Ammonia excretion was dependent on the NH3 partial pressure gradient (deltaPNH3) across the gills and independent of Na+ influx and acidification of the gill water boundary layer. Acute exposure to more alkaline water (pH 10) decreased ammonia excretion by 52 %, while exposure to neutral water (pH 7.6) increased ammonia excretion by 200 %. When fish were held in a ‘closed system’ for 8 h, ammonia excretion decreased as water ammonia levels increased over the first 6 h. However, after 6 h a marked increase in ammonia excretion occurred which may have been associated with an increase in the PNH3 gradient and/or activation of a carrier-mediated transporter. We conclude that Lahontan cutthroat trout, adapted to pH 9.4 water, maintain N-waste excretion by modifying mechanisms common to other teleosts. These modifications include lower rates of ammonia excretion, a higher ratio of urea excretion to ammonia excretion, a higher rate of renal ammonia excretion, greater plasma pH and greater total ammonia level (increased plasma PNH3), which facilitate the diffusive excretion of NH3 across the gills, and a lack of dependence of ammonia excretion on Na+ influx.
72 citations
TL;DR: In this paper, the Indian Ocean nodules can be leached in ammoniacal solution in the presence of glucose and various parameters chosen for leaching studies were: amount of glucose, time, pH, temperature, concentrations of ammonium and ammonium salt, and particle size.
72 citations
TL;DR: In this article, the effects of dietary urea-calcium (a slow rumen-release urea source) on absorption of ammonia N from the gut and urea N production in the liver were evaluated with Angus or Holstein steers.
72 citations
TL;DR: In this article, Urea was either broadcast on the surface or mixed with four soils (two clay-loams, two sandy loams) and losses of ammonia were measured when the soils were maintained at 40, 50, or 60 per cent water-holding capacity (WHC) and incubated at 5° or 25°C.
Abstract: Summary
Urea supplying 100 1b of N/acre was either broadcast on the surface or mixed with four soils (two clay-loams, two sandy-loams) and losses of ammonia were measured when the soils were maintained at 40, 50, or 60 per cent water-holding capacity (WHC) and incubated at 5°or 25°C. Urea and ammonium sulphate were similarly applied to two calcareous soils at 40 per cent WHC and 5°or 25°C. Losses varied most among soils, from 2 per cent of the N applied from an unmanured clay-loam to 13 per cent from an unmanured sandy-loam. Changing temperature and water content affected losses little on average, but their effects differed with different soils. Losses of ammonia were similar from urea and from ammonium sulphate applied to the calcareous soils. Analyses at the end of the experiments showed that: (i) nitrite tended to accumulate in the sandy and calcareous soils, accumulation being favoured by lower temperature and wetter soil; (ii) ammonia was lost at 25° C from calcareous soils until all the ammonium- N had been nitrified, from the slightly alkaline clay soils until nine-tenths had been nitrified, and from the neutral sandy soils until half had been nitrified.
72 citations