Desorption of 137Cs from Homalothecium sericeum (Hedw.) Schim. moss using weakly acid solutions

• Main Authors: Čučulović Ana A., Veselinović Dragan S.
• Format: Article
• Language: English
• Published: Association of Chemical Engineers of Serbia 2013-01-01
• Series: Hemijska Industrija
• Subjects: 137Cs desorption; Homalothecium sericeum (Hedw.) Schim.; acid rain
• Online Access: http://www.doiserbia.nb.rs/img/doi/0367-598X/2013/0367-598X1300014C.pdf

Desorption of 137Cs from Homalothecium sericeum (Hedw.) Schim. moss was performed using five consecutive desorptions with five identical solution volumes. The following solutions were used for desorption: H2SO4, HNO3 and their mixture H2SO4-HNO3, with pH values of 4.61; 5.15 and 5.75; and also distilled water pH 6,50. After five consecutive desorptions from 22.8% (solution H2SO4-HNO3 pH 5.75) to 33.2% (solution H2SO4-HNO3 pH 4.60) of 137Cs was desorbed by the sorbed acid, while by distilled water 31.3% of 137Cs was desorbed. The highest amount of 137Cs is desorbed by the first desorption, from 9.0% to 17.9%. Mean values of the total percentage of desorbed 137Cs from moss are similar: for solution H2SO4 28.8%; HNO3 25.7% and H2SO4-HNO3 28.6%, that indicates that NO3- and SO42- anions do not have an influence on Cs+ desorption. The used pH values of solutions do not significantly influence 137Cs desorption from moss. After five consecutive desorptions 137Cs is not significantly desorbed from moss. In the pH interval of 4.61 to 6.50 the desorbed substances are H2O and H+ ions, while SO42- and NO3- ions have a smaller influence. There are two sorption points, i.e. two sorption types where one is dominant. [Projekat Ministarstva nauke Republike Srbije, br. III 43009]