A case study of cesium sorption onto concrete materials and evaluation of wash agents: implications for wide area recovery

Publication date: Available online 7 May 2019Source: Journal of Environmental Chemical EngineeringAuthor(s): Michael D. Kaminski, Carol J. Mertz, James Jerden, Michael Kalensky, Nadia Kivenas, Matthew MagnusonAbstractTo support the viability of a wash-down approach to mitigating nuclear contamination, this study presents a characterization of the aggregate of a common concrete by optical microscopy and the sorption-desorption characteristics of cesium from these into potential wash solutions. Various minerals with weathered surfaces displayed strong affinity for 137Cs with an effective partition coefficient Kd = 120 mL/g for micas,>25-90 mL/g for feldspars, and>25-30 mL/g for amphiboles. The desorption Kd into 0.1 M NH4Cl varied greatly but for amphiboles, sandstones, granite, and fine-grained quartzite it was>200 mL/g as a result of irreversible sorption. These same mineral phases are prevalent in all types of building materials, extending our conclusions more broadly to the problem of wide-area urban decontamination. In contrast, ionic solutions desorbed up to 98% of 137Cs from cement, suggesting that fresh concretes with an intact surface layer of cement could be more easily decontaminated if Cs+ interactions with the underlying minerals could be avoided. For practical applications common, non-hazardous chemicals such as sodium, potassium, and ammonium salts are as effective or more effective than harsher chemicals and expensive chelating agents. For example,...
Source: Journal of Environmental Chemical Engineering - Category: Chemistry Source Type: research