Waste nitrate disposal

The technology of nitration processes is unavoidably associated with the problem of waste water disposal. The water, which comes from washing the nitration product, contains acid components from the nitrating mixture, and nitro compounds. 

Some of the better studied sites contaminated with Sr and Cs include (i) The Nitrate Disposal Pit at Chalk River Nuclear Laboratory in Ontario, Canada (ii) The A Disposal area at Chalk River the 100-K and 100-N area at the Hanford Site in Washington the 200 East area at Hanford, the 600 area at Hanford the Maxey Flats Low Level Waste (LLW) Site in Kentucky the West Valley LLW Site in New York, the Sheffield LLW Site in Illinois and the Barnwell LLW site in South Carolina. Barnwell is the only active LLW disposal site among those listed above. Surface water and soil contamination by Sr and Cs exists at Oak Ridge National Laboratory in Tennessee. There also is an apparently stable Sr plume at Brookhaven National Laboratory on Long Island. 

Robertson, D.E., M.P. Bergeron, P.A. Myers, K.H. Abut, L.W. Thomas, D.R. Champ, R. Killey GL. Moltanyer, and J.L. Young. 1987. Demonstration of performance modeling of a low-level waste shallow-land burial site A comparison of predictive radionuclide transport modeling versus field observations at the nitrate disposal pit site. Chalk River Nuclear Laboratories. U.S. National Research Council, Washington, DC. 

PoIIuta.ntReduction. Pollutants from explosives are primarily produced by waste from the explosives manufacture, such as the acids used ia nitration (qv). Pollutants may also be produced dufing iacorporation of the explosives ia munitions, ia the use of iadustrial explosives, and ia clean-up and disposal operations. Table 4 fists the most common types of pollutants found ia the manufacture of explosives, as well as effects and various procedures for reduction (41—54). 

Acetic anhydride and acetic acid increase the solubiUty of the two phases in each other, and they are employed for the commercial N-nitration of hexamethylenetetramine [100-97-0] (11) to form cyclotrimethylenetrinitramine [121-82-4] (RDX), (CH2)3(NN02)3. Renewed consideration has been given to replacing H2SO4 with an improved soHd catalyst to reduce the environmental problems of disposal or reconcentration of the waste acid and to increase production of desired nitrated isomers. For example, a catalyst with suitable pore size might increase the production of 4-MNT and reduce that of 3-MNT when toluene is nitrated. 

A significant concern in all nitration plants using mixed acids centers on the disposal method or use for the waste acids. They are sometimes employed for production of superphosphate ferti1i2ers. Processes have also been developed to reconcentrate and recycle the acid. The waste acid is frequently first stripped with steam to remove unreacted HNO and NO. Water is then removed by low pressure evapori2ation or vacuum distillation. 

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. 

These three steps all produce significant amounts of waste. First, as discussed earlier, the nitration process results in the production of spent sulfuric acid. In the past the company had been able to sell much of this material to the coke and steel industries but declining demand meant that the acid now required disposing of, at additional cost. At the time green catalytic nitration technology was becoming available with clay, zeolite and lanthanide catalysts all providing possible alternatives to the use of sulfuric acid (see below). Improved selectivity to the desired para-isomer is an added benefit of some of these catalytic systems. However on the... 

Vegetables are also a prime source of nitrate, and variations in their nitrate levels occur due to conditions employed during the cultivation and storage processes. The nitrate concentration in surface water has increased due to increased use of artificial fertilizers, changes in land use and disposal of waste from intensive fanning. Nitrate is readily converted in mammalian systems through bacterial and mammalian enzymes to nitrite which can react with amines, amides and amino acids to form NOC. 

Small quantities of hazardous solid wastes (such as potassium dichromate, lead nitrate, silver nitrate, asbestos, etc.), liquid chemicals (such as chloroform, PCB, methylene chloride, etc.), petrochemicals (such as gasoline. No. 2 fuel oil, etc.), or pure metals (such as mercury, sodium, etc.), which are stored in bottles or cans, however, are not considered to be hazardous household products. Accordingly these nonhousehold hazardous solid wastes, even in small quantities, can only be properly disposed of by licenced or certified environmental professionals. 

Researchers concluded that ion exchange removal of nitrate was cost prohibitive at the Livermore site because of the high cost of waste disposal. The perchlorate-only alternative with nitrate removal using another technology was the most cost-effective solution. Perchlorate disposal costs under this option were 350/year, and minimal maintenance of the treatment unit would be required (D20493D, p. 12). The cost estimates are summarized in Table 1. 

Process pH, sodium, calcium, and nitrate concentrations, plugging of the ion exchange column, lot variance, and the presence of binders can affect process efficiency. lonsiv IE-911 does not remove anionic radioactive ions such as technetium. The resins are designed for one-time use and must be replaced when loaded. The waste acceptance criteria at the resin disposal facility may limit the loading of the CST resin. Size constraints of the cesium removal system (CRS) may limit system flow rates. 

XVI) Laboratory Disposal of LA by the Method of Wm. H. Rinkenboch. Disperse with stirring ca 1 oz of waste LA in 1.5 gal 10% aq Amm acetate soln, add 2.5 oz of Na nitrate dissolved in 1 pint of w and then 7 oz of glacial AcOH or its equivalent of weaker acid. After allowing the soln to stand in a warm place for at least 1 hour, dispose of it... 

See in Vol 8, P317-L to P324-L, under Pollution Abatement in the US Military Explosives and Propellants Manufacturing Industry N85-R to N86-L, under Nitration and under sub-topic Disposal of Waste TNT in article on TNT in Vol 9... 

Pollutants from point sources domestic sewage (detergents), industrial effluents (synthetic organics, metal cyanides, metals, caustic chemicals), landfill waste disposal (metallic ions, chloride, nitrate, nitrite, sulfate, and synthetic organics). 

Fig. 1. Schematic flowsheet of uranium processing (acid leach and ion exchange) operation. Numbers refer to the numbers that appear in the boxes on the flowsheet. Operations (3), (6), (9), and (11) may be done by thickening or filtration. Most often, thickeners are used, followed by filters. The pH of the leach slurry <4) is elevated to reduce its corrosive effect and to improve the ion-exchange operation on the uranium liquor subsequently separated, In tile ion exchange operation (7), resin contained in closed columns is alternately loaded with uranium and then eluted. The resin adsorbs the complex anions, such as UC fSO 4-. in which the uranium is present in the leach solution. Ammonium nitrate is nsed for elution, obtained by recycling the uranium filtrate liquor after pH adjustment. Iron adsoibed with the uranium is eluted with it. Iron separation operation (8) is needed inasmuch as the iron hydroxide slurry is heavily contaminated with calcium sulfate and coprecipitated uranium salts. Therefore, the slurry is recycled to the watering stage (3). Washed solids from 1,6). the waste barren liquor from (7), and the uranium filtrate from (11) are combined. The pH is elevated to 7.5 by adding lime slurry before the mixture is pumped to the tailings disposal area. (Rio Algom Mines Limited, Toronto)...

Fig. 7.4. Mercury pickup devices, (a) Vacuum pickup device. Collected mercury is trapped in the flask for recycling or disposal. (b) Amalgamated copper wire pickup device. The wire is first cleaned in nilric acid, then dipped into a solution of mercuric nitrate to give a thin coating of mercury. Droplets of mercury readily cling to the spiral and may be shaken off into a mercury waste container.

The US Navy has also investigated the use of biodegradation for the disposal of TNT containing rinse w ( pink water ) (Ref 41). Likewise, the combined disposal in stabilization ponds of monomethyl hydrazine, nitrate and nitrite salts and nitrogen tetroxide waste liquors... 

The conventional nitration process,[2,5] that involves a mixture of nitric and sulfuric acids (mixed acids method) has remained unchallenged, in the commercial area, for the last 150 years owing to the very favourable economics. However, the method is notoriously unselective for nitration of substituted aromatic compounds and the disposal of waste products and spent acids is a serious environmental issue. For instance, nitration of toluene for production of mononitrotoluenes (MNTs) is conducted using a nitrating mixture usually composed of 52-56 % (w/w) H2SO4, 28-32% (w/w) HNO3 and 12-20% (w/w) H20. The reaction performed at temperatures between 25 and 40°C, yields ca. 96 % MNTs, which are composed of a mixture of ca. 60 % (w/w) o-nitrotoluene, ca. 37 % (w/w) p-nitrotoluene and... 

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