Continuous electrolytic decarbonation and recovery of a carbonate salt solution from a metal-contaminated carbonate solution.
This work studied the characteristic changes of a continuous electrolytic decarbonation and recovery of a carbonate salt solution from a metal-contaminated carbonate solution with changes of operational variables in an electrolytic system which consisted of a cell-stacked electrolyzer equipped with a cation exchange membrane and a gas absorber. The system could completely recover the carbonate salt solution from a uranyl carbonato complex solution in a continuous operation. The cathodic feed rate could control the carbonate concentration of the recovered solution and it affected the most transient pH drop phenomenon of a well type within the gas absorber before a steady state was reached, which caused the possibility of a CO(2) gas slip from the gas absorber. The pH drop problem could be overcome by temporarily increasing the OH(-) concentration of the cathodic solution flowing down within the gas absorber only during the time required for a steady state to be obtained in the case without the addition of outside NaOH. An overshooting peak of the carbonate concentration in the recovered solution before a steady state was observed, which was ascribed to the decarbonation of the initial solution filled within the stacked cells by a redundant current leftover from the complete decarbonation of the feeding carbonate solution.
Kim
Kwang-Wook
KW
Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong, Daejeon Republic of Korea. nkwkim@kaeri.re.kr
Kim
Yeon-Hwa
YH
Lee
Se-Yoon
SY
Lee
Eil-Hee
EH
Song
Kyusuk
K
Song
Kee-Chan
KC
D000327:Adsorption; D002244:Carbon / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry*; D002412:Cations; D004563:Electrochemistry / Q000379:methods*; D005740:Gases; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D008956:Models, Chemical; D012492:Salts / Q000737:chemistry; D012972:Sodium Hydroxide / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods
D002254:Carbonates; D002412:Cations; D005740:Gases; D006878:Hydroxides; D008670:Metals; D012492:Salts; D014874:Water Pollutants, Chemical; D002245:Carbon Dioxide; D012972:Sodium Hydroxide; D002244:Carbon