[Radiolysis of aqueous solution of thiocyanate by gamma-rays].

Radiolysis of aqueous solution of thiocyanate by 60Co gamma-rays was studied. In condition of pH = 1 and pH = 3,25 mg/L SCN- was decomposed under the dose of 6 kGy, with decomposition rate of 98.11% (pH = 1) and 95.97% (pH = 3) respectively. 25 mg/L SCN- (pH = 7) was decomposed under the dose of 9 kGy and the decomposition rate is 99.33%. In the alkaline condition, pH = 10 and pH = 12, the dose of 18 kGy was need, and the decomposition rate is 99.64% and 99.93% respectively. High SCN- concentration means that more radiation dose is need. From the comparison of before radiolysis and after radiolysis's TOC (total organic carbon) and TN (total nitrogen) of SCN- solution, little TOC and TN was removed. The determination of SO4(2-) and NO3- concentration indicated that sulfur element was removed and converted to SO4(2-), and nitrogen element rarely converted to NO3-, but converted to other forms of nitrogen.

[Radiolysis of aqueous thiocyanate and its complicated system].

We studied the 60Co gamma-ray radiolysis of thiocyanate aqueous solutions in the presence of free radical scavengers, determination of cyanide of radiated thiocyanate solutions, degradation of cyanide and thiocyanate complicated system and cyanide, thiocyanate and copper (I) cyanide complicated system. The presence of NaHCO3 and n-butanol made the degradation efficiency of thiocyanate decreased, in the radiation procession of thiocyanate, cyanide was produced; and the possible reaction equation is SCN(-) + 8*OH-->SO4(2-) + CN(-) +4H2O, in the cyanide and thiocyanate system, the thiocyanate degradation rate can obtained 30%, free cyanide degradation was little effected by coexistence of thiocyanate; and due to strong complex ability of copper (I), the main form of copper (I) cyanide is Cu(CN)3(2-), the total cyanide of the system can't be degraded completely and degradation rate is about 80%.