Selective Uptake of Cesium by Ammonium Molybdophosphate (AMP)-Calcium Alginate Composites

Abstract

The uptake properties of Cs + for ammonium molybdophosphate (AMP, (NH 4 ) was found to have a relatively low value of −9.7 kJ/mol compared to other inorganic ion exchangers, indicating high selectivity of AMP for Cs + ions. The fine crystals of AMP exchanger were granulated with calcium alginate (CaALG) gel polymer as an immobilization matrices. The uptake rate of Cs + for AMP-CaALG composite was fairly fast and the uptake attained equilibrium within 3 h; the uptake was above 96% even in the presence of 5 M (=mol/dm 3 ) NaNO 3 . The distribution coefficient of Cs + , K d,Cs , decreased in the order of coexisting ions, H + >Na + >K + >NH + 4 . In a wide HNO 3 concentration region of 10 −2 -5 M, the K d,Cs value for the composite was around 10 4 cm 3 /g, while those for other elements, Na + , Sr 2+ , Co 2+ , Eu 3+ and Am 3+ , were less than 10 2 cm 3 /g. The uptake of Cs + followed a Langmuir adsorption isotherm, and the uptake capacity of Cs + increased with the content of AMP immobilized in the composite. The trace amounts of Cs + in the presence of HNO 3 were selectively adsorbed on the composite column.)

Synthesis of Tobermorite from the Ash after Treatment of Asbesto-Containing Disaster Waste, and Its Removal Ability of Cs(I) from Aqueous Solution

“…Among them, ion exchange using different materials is the most studied [14]. Much attention has been focused toward the uptake of Cs + on zeolites [15][16][17][18], clay minerals [13,14,[19][20][21][22], and other adsorbents [23][24][25][26][27].…”

Radionuclides: Accumulation and Transport in Plants

“…Specific absorption mechanism in soil by plant may depend upon several factors like availability and exchangeability of Cs along with the particular salt content and its interionic effects, soil type, water submergence time etc. (Tensho et al 1961, Mimura et al 2001. Salts like ammonium molybdophosphate (AMP) and rubidium chloride augment in uptake of Cs from soil.…”

“…Salts like ammonium molybdophosphate (AMP) and rubidium chloride augment in uptake of Cs from soil. The application of AMP for partitioning and recovery of radioactive 137 Cs from HNO 3 and NaNO 3 rich liquid waste is well documented (Mimura et al 2001).…”

Preparation and characterization of a novel electrospun ammonium molybdophosphate/polyacrylonitrile nanofiber adsorbent for cesium removal

“…Recently, different adsorbents were used for Cs ? removal from aqueous solutions using prussian blue caged in alginate/calcium beads [13], potassium hexacyanocobalt ferrate [14], ammonium molybdophosphate-calcium alginate composite [15] and polyacrylonitrile based manganese dioxide composite [16]. Among the previous adsorbents, combination of ammonium molybdophosphate-polyacrylonitrile (AMP-PAN) in the form of granule composite prepared by Sebesta [17] and later developed by Park et al [18] had effective properties of removing Cs ?…”