Disposal of ammonia

The reason ammonia must be removed from tissues is its toxicity above concentrations of 1 mM. This is largely a result of its effect on the Krebs cycle as 

The second reaction in the urea cycle is the condensation of carbamoylphosphate with ornithine, a basic amino acid not found in proteins but readily formed from glutamate (see later). The product is another basic amino acid called 

Note that the second nitrogen atom of urea originates from the amino group of aspartate. Cytosolic amino acid nitrogen is the source of aspartate nitrogen, as shown in Equation (20.18) through (20.20)  

Amino acid + oxaloacetate --------------- a-keto acid + aspartate (20.18) 

The oxaloacetate produced may now repeat the cycle. Alternatively, the fuma-rate produced in the urea cycle may enter the Krebs cycle to become metabolized or to yield glucose. Depletion of oxaloacetate, for example under conditions of starvation or fasting or in malonate poisoning of the Krebs cycle, limits the extent of urea formation. 

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Martin, W. J., Martin, J. E., Horler, S. Nikolaus, T. 1993. Process for Extracting of Disposing of Ammonia or Ammonia Compounds from Dust Mixtures. US Patent No. 5,211,926. 

One of the major waste products of glucose metabolism in peripheral tissues is the amino acid alanine and its use as a substrate for glucpnepgenesis requires the disposal of ammonia in the urea cycle In the following discussion we will illustrate how the flow of the label from alanine into products byproducts and intermediates of gluconeogenesis can be used to obtain qualitative and quantitative information about the relative activities of these pathways ... 

Ammonia has been identified in at least 135 of the 1,613 hazardous waste sites that have been proposed for inclusion on the EPA National Priorities List (NPL) (HazDat 2002). However, the number of sites evaluated for ammonia is not known. The frequency of these sites can be seen in Figure 6-1. Of these sites, 132 have been identified that are located within the United States and 2 sites have been identified that are located in the Commonwealth of Puerto Rico (not shown). Significant amounts are also released during the manufacture, formulation, transport, storage, and disposal of ammonia (see Section 6.2). 

In the urea cycle, arginine is cleaved to yield urea and ornithine. The fact that birds require arginine in their diet indicates that they are unable to synthesize it for utilization in protein synthesis. As a result, they are also unable to synthesize urea to dispose of ammonia ... 

Under some circumstances, ammonia in a container is colder than the available water supply. At such times, water must not be sprayed on the container walls since it would heat the ammonia and aggravate any gas leak. If it is found necessary to dispose of ammonia, as from a leaking container, liquid ammonia may be discharged into a receptacle containing water sufficient to absorb it. Sufficient water may be considered as 10 parts of water to 1 part of ammonia. The ammonia must be injected into the water as near the bottom of the receptacle as practical. 

The vapor product from the ammonia stripper can be processed by one of the options shown in Figure 4-23 for recovery or disposal of ammonia. When the quantity of ammonia produced or the local ammonia market make the production of salable ammonia uneconomical, the ammonia-rich vapor can be incinerated by using it as fuel in a process furnace or boiler. To prevent air pollution it may be necessary to scrub the ammonia-rich stream with water before burning it This generates a small amount of sour water, which can be recycled to the plant feed stream. 

The ratio of reactants had to be controlled very closely to suppress these impurities. Recovery of the acrylamide product from the acid process was the most expensive and difficult part of the process. Large scale production depended on two different methods. If soHd crystalline monomer was desired, the acrylamide sulfate was neutralized with ammonia to yield ammonium sulfate. The acrylamide crystallized on cooling, leaving ammonium sulfate, which had to be disposed of in some way. The second method of purification involved ion exclusion (68), which utilized a sulfonic acid ion-exchange resin and produced a dilute solution of acrylamide in water. A dilute sulfuric acid waste stream was again produced, and, in either case, the waste stream represented a... 

Thermal degradation of isocyanates occurs on heating above 100—120°C. This reaction is exothermic, and a mnaway reaction can occur at temperatures >175° C. In view of the heat sensitivity of isocyanates, it is necessary to melt MDl with caution and to foUow suppHers recommendation. Disposal of empty containers, isocyanate waste materials, and decontamination of spilled isocyanates are best conducted using water or alcohols containing small amounts of ammonia or detergent. Eor example, a mixture of 50% ethanol, 2-propanol, or butanol 45% water, and 5% ammonia can be used to neutrali2e isocyanate waste and spills. Spills and leaks of isocyanates should be contained immediately, ie, by dyking with an absorbent material, such as saw dust. 

The plant disposes of two waste streams gaseous and aqueous. The gaseous emission results from the ammonia and the artunonium nitrate plants. It is fed to an incinerator prior to atmospheric disposal. In the incinerator, ammonia is converted into NOj,. Ehie to more stringent NO regulations, the conqmsition of ammonia in the feed to the incinerator has to be reduced from 0.57 wt% to 0.07 wt%. The lean streams presented in Table 9.5 may be employed to remove ammonia. The main aqueous waste of the process results from the nitric acid plant. Due to its acidic content of nitric acid, it is neutralized with an aqueous ammonia solution before biotreatment. 

Stripping of hazardous substances Mercury switches and other components containing particularly hazardous substances must be removed CFCs are recovered from the cooling circuit and PU foam with special equipment and appliances with varying degrees of automation ammonia is dissolved in water and separate disposal of waste oil (from compressors). 

Liver disease due to alcohol abuse, chronic hepatitis, or hemochromatosis, leads to impairment of ammonia disposal by the urea cycle and is often the cause of this condition in adults. 

Most bore waters include high concentrations of at least one of the following chemical contaminants (Table 1) lithium (Li), boron (B as H3BO3), arsenic (As), hydrogen sulphide (H2S), mercury (Hg), and sometimes ammonia (NH3). If released into a river or lake, these contaminants can potentially damage aquatic life, terrestrial plants, and/or human health. The disposal of highly saline bore waters can also have an adverse effect on water quality. 

The initial process to achieve success was developed by Miyata of Kyowa in the mid 1970s [101].This process is based on the hydrothermal conversion in an autoclave of the fine agglomerated particles formed by addition of ammonia or lime to a magnesium salt solution. This hydrothermal conversion results in the formation of particles of about 1 micron in size and with a fairly low aspect ratio. This original process appears to be expensive to operate because of the low value of the ammonium or calcium chloride co-product which has to be disposed of and because the reported reaction conditions give a low yield and a relatively slow reaction. 

The element has a definite fertilising action 2 which is exerted in two ways (1) It supplies sulphuric acid by bacterial oxidation, the presence of the acid increasing the availability of certain mineral constituents in the soil, such as alkalis, ferric oxide, alumina and phosphates. (2) It facilitates the work of the ammonia and nitrifying bacteria, thus placing larger supplies of nitrogen at the disposal of the plants. But although such action may be beneficial in some soils it is equally harmful in others, and sulphur should not be applied to a soil already acid.3... 

Ammonia is produced by all tissues during the metabolism of a variety of compounds, and it is disposed of primarily by formation of urea in he liver. However, the level of ammonia in the blood must be kept very fcw, because even slightly elevated concentrations (hyperammonemia) ae toxic to the central nervous system (CNS). There must, therefore, be a metabolic mechanism by which nitrogen is moved from peripheral tissues to the liver for ultimate disposal as urea, while at the same hre low levels of circulating ammonia must be maintained. 

Can be prepd by treating freshly pptd Cu(0H)2 with thyocyanic acid or by other method. In presence of ammonia, it forms ammoniacates (ammines), which are more stable tha n Cu(SCN)z (Refs 1, 2 9). No iafo at our disposal about its uses... 

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