Nitrate salts removal from waste water

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 ... 

Since 2003, RO-based unit operation to remove the radionuclides C Cs, ° Ru, U, Pu) from delay tank is continued, and the performance of the system was found to be promising [49-51]. The final discharge of low-level active waste (i.e., a mixture of evaporator condensate, ADU filtrate, and waste generated from personnel contamination [like hand washing to remove contamination from hand]) is carried out from the delay tank, which temporarily holds low-active waste. We thus evaluated RO for the removal of alpha activity, beta activity, nitrates, and total dissolved salts (TDSs) from delay tank water at the pilot plant. The delay tank water composition is given in Table 26.4. The specification of the membrane module, which was supplied by the Desalination Division of the BARC (Mumbai), is listed in Table 26.5. The module was... 

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