Nitrates destruction

According to the vendor, this project could provide a compact, low-cost reactor to treat aqueous mixed waste streams containing nitrates or nitrites, eliminate the need for chemical reagents, and minimize or eliminate secondary wastes such as nitrous oxide and secondary products such as ammonia, H2, and O2 that are prevalent with other nitrate destruction processes. By removing nitrates and nitrites from waste streams before they are sent to high-temperature thermal destruction and vitrification, production of NO can be decreased with the attendant decrease in off-gas system requirements. Biocatalytic nitrate destruction is applicable to a wide range of aqueous wastes with a highly variable composition. All information is from the vendor and has not been independently verified. 

Also, nitrate electroreduction is estimated by prolonged electrolysis by controlling either the potential or the current. The electrode performance for nitrate electrolysis is evaluated by measuring the nitrate destruction yield, the current efficiency, the selectivity and the specific energy consumption [15, 16]. During electrolysis, products can be accurately detected and quantified by ionic/gaseous chromatography, and UV-Vis spectroscopy. 

Unlike nitration. 2-amino-4-methylselenazole can be directly bromi-nated, using bromine in carbon tetrachloride solution, to give 2-amino-5-bromo-4-methylselenazole hydrobromide [m.p. 180°C (decomp.)] (19). The free base cannot be isolated. Use of excess of bromine can lead to destruction of the molecule. 

Nitration has been described as the most widespread and powerfully destructive industrial unit process operation [10]. 

Although direct nitration was not possible, 2-amino-4-methylselena-zole can be directly brominated by treatment with bromine in carbon tetrachloride, the hydrogen bromide salt of 2-amino-4-methyl-5-bromoselenazole, mp 180°C (decomp.) is formed. However, all attempts to obtain the free base from this salt failed and led to complete decomposition. In this bromination, an equivalent quantity of bromine must be used excess also leads to complete destruction of the molecule. From the decomposition products an oily compound can be detected similar to bromoacetone. ... 

The reaction takes place above 20 atms press and above 482°, with suitable H2 partial press and contact time necessary to obtain destructive hydrogenation without the formation of poly merized material. The resulting hydroformed naphthas may be halogenated, sulfonated or nitrated... 

The following reaction often leads to destructive accidents. To avoid this, potassium dichromate in the solid state should not come into contact with the nitrated derivative. 

A demonstration by Berthollet in 1788 of replacement of potassium nitrate in gunpowder by the chlorate led to a violent explosion during the crushing operation which caused two fatalities. Later incidents involving factories for chlorate-containing explosives led to widespread destruction. 

This process is of interest for the destruction of nitrate in water and nitrate electrocatalytic reduction offers a possible route to treat contaminated water. 

The disulfide bridge of bis(3-nitrofurazan-4-yl)disulfide 213 was shown to undergo transformations of a new type, such as destructive nitration to give 3,4-dinitrofurazan 214 and 4,4 -dinitroazoxyfurazan 215 (Equation 41) <2004RCB722>. 

Heat, and sometimes gas, transfer from the core of a bulk material, also influences auto-ignition and explosion. The concept of critical mass is not limited to nuclear explosives (though shape is also important). Some entries in this text, such as sodium chlorate, ammonium nitrate and ammonium perchlorate, have proved extremely destructive dining industrial storage by the tens of tonnes, but are incapable of explosion at the ten gramme scale. Many other entries are for hazards significant only beyond laboratory scale [1]. 

Changes in phosphate, nitrate, ammonia, and silicate concentrations associated with the biogenic production and destruction of POM can alter seawater alkalinities. These effects are usually so small in scale that they can be ignored. Since the largest biotic impact on alkalinity in oxic seawater is exerted by the formation and dissolution of... 

Commercial 70 % nitric acid can be used for the 6>-nitration of low molecular weight alcohols like ethanol and 2-propanol. The nitrate ester products are isolated from the cautious distillation of a mixture of the alcohol and excess 70 % nitric acid. The presence of urea in these reactions is very important for the destruction of nitrous acid and its omission can lead to very violent fume-off. However, this method is not recommended on safety grounds. Using temperatures above ambient for the O-nitration of alcohols, with either nitric acid or mixed acid, is dangerous and greatly increases the risk of explosion. 

The harsh conditions needed to introduce five or more nitro groups into diphenyl ether lead to the destruction of the aromatic ring. Highly nitrated derivatives of diphenyl ether can be prepared by an indirect route 2,2, 4,4, 6-pentanitrodiphenyl ether (92) is the product from the controlled nitration of (91), which is obtained from the reaction of picryl chloride (87) with sodium o-nitrophenolate. ... 

Agrawal and co-workers" " also conducted extensive studies into the synthesis, characterization and thermal and explosive behaviour of (113) (K-56, TNABN). 2,5,7,9-Tetraazabi-cyclo[4.3.0]nonane-8-one (112) was synthesized from the direct reaction of ethylenediamine with glyoxal, followed by reaction of the resulting cyclic imine with urea in concentrated hydrochloric acid nitration of (112) was achieved in 51 % yield with a mixture of nitric acid-acetic anhydride. Agrawal showed that K-56/TNABN is significantly more resistant to hydrolytic destruction than TNGU. 

A cooler-burning pyrotechnic composition based on cellulose nitrate and guanidine nitrate has been developed which produces reaction temperatures of less than 500 °C, thus causing less destruction of the dye. 

Many of the oxidizers should be familiar to those experienced in investigating bombings. Prime examples are NH4NO3 (ammonium nitrate) and KCIO3 (potassium chlorate), both of which are utilized to make bombs on a regular basis. Other materials may appear more exotic but have equal destructive potential. It should be noted that some oxidizer families such as chlorates, nitrites, and peroxides are very reactive. When used in IE formulations, these oxidizers can create very sensitive mixtures, which need to be approached with extreme caution. 

T0061 Argonne National Laboratory, Biocatalytic Destruction of Nitrate... 

Biocatalytic destruction is the focus of an ongoing project to develop an enzyme-based reactor system that uses naturally occurring reductase enzymes to reduce nitrate and nitrite present... 

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