|About this Abstract
||Part C-1: Hydrometallurgy 2018
||Alkaline Metals Removal from Radioactive Wastewater by Combined CO2 Capture and Adsorption into Bone Char
||Elbert Muller Nigri, André Luiz Alvarenga Santos, Leonardo Fernandes Santos, Sonia Rocha
|On-Site Speaker (Planned)
Radioactive wastewater from nuclear source of electrical energy production needs to be treated and disposed. Sr, Ca, Mg and Ba are common elements in this effluent which can cause incrustation and also be dangerous to human health (90Sr). Fixation of CO2 can be applied to brines to remove the ions mentioned and provide a solution where CO2 is sequestered and the deleterious elements precipitated, becoming one of the possible steps to get the water reused back into the process. Moreover, removal of several metals from distinct wastewater have been evaluated using bone char through adsorption. The chemical similarity of calcium and strontium makes the substitution of these metals into hydroxyapatite structure of bone char. This paper evaluated the combined action of precipitation and adsorption process with injection of CO2 and bone char adsorbent in simulated nuclear wastewater. Removal of 89.0% (Sr) and 83.3% (Ca) was obtained in combined process. The presence of bone char as seed increased the precipitation kinetics, allowing a Sr removal of 85.2 % in five minutes, higher than 75.3 % obtained in absence of seeds. However, at longer times (25h) removal of 91.6% (Sr) and 89.8% (Ca) were obtained in absence of seeds. Analysis of solids have evidenced that CO2 was consumed to precipitate the metals in carbonate form.
||Planned: At-meeting proceedings