Waste water nitrate removal from

R. Grinstead K.C. Jonos, Nitrate Removal from Waste Water by Ion Exchange , Rpt 17010 FSJ, US Environmental Protection Agency (1971) 11) D.H. Rosenblatt, G-E. 

Suharti, Strampraad MJ, Schroder I, de Vries S (2001) A novel copper A containing menaquinol NO reductase from Bacillus azotoformans. Biochemistry 40 2632-2639 Sumino T, Isaka K, Ikuta H, Saiki Y, Yokota T (2006) Nitrogen removal from waste-water using simultaneous nitrate reduction and anaerobic ammonium oxidation in single reactor. J Biosci Bioeng 102 346-351... 

In the presence of nitrate, formate dehydrogenase-N (FDH-N) and nitrate reductase are induced (8). As a result, the formate is consumed preferentially by FDH-N due to its inherent high affinity for formate versus FDH-H. The Km value for formate of FDH-N is 0.12 mM, while that of FDH-H is 26 mM. The FHL system is induced by the presence of formate, however, formate consumption by an FDH-N - nitrate reductase system depresses the expression level of the FHL system. Consequently, both expression of FHL and hydrogen production are repressed by the presence of nitrate in the medium. The removal of nitrate from waste water is not a practical process therefore a bacterial strain capable of hydrogen production even in the presence of nitrate is favorable. The subunits of nitrate reductase are encoded in the fdn operon. The a-subunit of nitrate reductase is encoded in the... 

Box 15.9 deals with the nitrogen cycle and the removal of nitrates and nitrites from waste water, (a) Urea is used to reduce [N02] to N2. Write a balanced equation for the reaction of HNO2 with urea, (b) Sulfamic acid is also used to reduce [N02] to N2 during water treatment. Give an equation for this reaction, (c) Nitrites can be removed using H2O2, [OCl] or HOCl as oxidants. How does the reduction potential for the following process depend on pH ... 

R/0 unit Reverse Osmosis Unit for water purification in small aquariums and miniature yard-ponds, utilizes a membrane under pressure to filter dissolved solids and pollutants from the water. Two different filter membranes can be used the CTA (cellulose triacetate) membrane is less expensive, but only works with chlorinated water and removes 50-70% of nitrates, and the TFC membrane, which is more expensive, removes 95% of nitrates, but is ruined by chlorine. R/0 wastes water and a system that cleans 100 gallons a day will cost ft-om 400 to 600 with membrane replacement adding to the cost. A unit that handles 140 gallons a day will cost above 700,00. 

Crude TNT contains isomers and nitrated phenolic compounds resulting from side reactions. The usual method of purification is to treat crude TNT with 4% sodium sulfite solution at pH 8-9, which converts the unsymmetrical trinitro compounds to sulfonic acid derivatives. These by-products are then removed by washing with an alkaline solution. Pure TNT is then washed with hot water, flaked and packed. It is important to remove the waste acid and unsymmetrical trinitrotoluenes together with any by-products of nitration as they will degrade the TNT, reduce its shelf life, increase its sensitivity and reduce its compatibility with metals and other materials. Trace amounts of unsymmetrical trinitrotoluenes and by-products will also lower the melting point of TNT. TNT can be further recrystallized from organic solvents or 62% nitric acid. 

Mercury salts have a number of important uses in industry and in chemical analysis. Because mercury compounds are poisonous, however, the mercury ions must be removed from the waste water. Suppose that 25.00 mL of 0.085 mol/L aqueous sodium sulfide is added to 56.5 mL of 0.10 mol/L mercury(II) nitrate. What mass of mercury(II) sulfide, HgS(s), precipitates ... 

Water used in the experiments was doubly distilled and passed through an ion exchange unit. The conductivity was approximately 1 x 10"6 S/m. Simulated HLLW consisted of 21 metal nitrates in an aqueous 1.6 M nitric acid solution as shown in Table 1 and was supplied by EBARA Co. (Tokyo, Japan). Concentrations were verified by AA for Na and Cs with 1000 1 dilution and by ICP for the other elements with 100 1 dilution. Total metal ion concentration was 98,393 ppm. The experimental apparatus consisted of nominal 9.2 cm3 batch reactors (O.D. 12.7 mm, I.D. 8.5 mm) constructed of 316 stainless steel with an internal K-type thermocouple for temperature measurement. Heating of each reactor was accomplished with a 50%NaNO2 + 50% KNO 2 salt bath that was stirred to insure uniform temperature. Temperature in the bath did not vary more than 1 K. The reactors were loaded with the simulated HLLW waste at atmospheric conditions according to an approximate calculated pressure. Each reactor was then immersed in the salt bath for 2 min -24 hours. After a predetermined time, the reactor was removed from the bath and quenched in a 293 K water bath. The reactor was opened and the contents were passed through a 0.1 pm nitro-ceflulose filter while diluting with water. Analysis of the liquid was performed with methods in Table 1. Analysis of filtered solids were carried out with X-ray diffraction with a CuK a beam and Ni filter. Reaction time was defined as the time that the sample spent at the desired temperature. Typical cumulative heat-up and cool-down time was on the order of one minute. Results of this work are reported in terms of recoveries as defined by ... 

Nitrogen( total) Wastewaters from urban waste water treatment plant Microwave-assisted oxidation of nitrogen-containing compounds to nitrate with an alkaline peroxydisulfate solution UV-Vis 0.21 mg L 1 Flow injection system chamber-like de- [434] bubbler for removal of the gaseous species formed during in-line oxidation nitrate reduction to nitrite Griess-Ilosvay reaction... 

Similar studies of application of anion exchangers Amberlite IRA-900 (macroporous, polystyrene, strongly basic anion exchanger of type 1, 16-50 mesh) [133-135] and Amberlite IRA-410 (gel, polystyrene, strongly basic of type 2,16-50 mesh) [135] for recovery and removal of trace amounts of Pd(II), Pt(II), Ru(III), Rh(III), Au(III) and Ir(IV) ions from chloride and radioactive nitrate waste waters were carried out by the Els et al. [133, 134] and El-Said et al. 

Fertilizers are a major source of phosphates entering rivers and lakes. However, domestic and industrial waste water (e.g. from detergent manufacturing) also contains [P04] and condensed phosphates, and the levels that must be removed before the waste can be discharged are controlled by legislation. In most cases, phosphates are removed by methods based on precipitation (this is the reverse of the situation for nitrate removal see Box 15.9). Fe, Al and Ca are most commonly used to give precipitates that can be separated by filtration. 

Chile, production is based on the Guggenheim method, which permits ores containing under 10% nitrate to be profitably worked. Caliche is mined by open-pit operations, using draglines and power shovels, and is crushed to about 80% between 3/4 and 3/8 inches (1.9-0.95 cm). This product is leached at about 40°C wth water in a series of vats each vat has a capacity of some 10,000 tonnes of crushed ore. The underflow from each vat is heated before passing to the next since sodium nitrate has a negative heat of solution. After extraction and washing are complete, the residue is removed from the vats and transported to a waste dump. 

The LEM technique was first proposed by Li (1) in the 1960s as a possible industrial technique for the separation of substances from aqueous solutions. Initially, Li s work concentrated on the separation of hydrocarbons and, later, on the removal of dissolved constituents (phenols, phosphoric acid, sodium nitrate, and ammonia) from aqueous solutions. During the 1970s, research on this technique was extended to the removal of copper from acidic leach solutions and the extraction of uranium from wet-process phosphoric acid (2-3), Research in Japan involved the extraction of NH3, Cr Hg , Cd ", and Cu " from industrial waste waters (4), Draxler, Furst, Protsch, and Man investigated the extraction of zinc from a waste water at a rayon plant in Austria (5-6), However,... 

---