Soluble and particle-bound^234,238U,²²⁶Ra and²¹⁰Po in ground waters

Abstract

Summary Water of five drilled wells was filtered with three membranes (pore size 0.45 µm-5 kD) to determine the soluble and particle-bound forms of 234,238 U, 226 Ra and 210 Po. Three of the waters were of Ca-HCO 3 type and two of Na-Cl type. Some of the waters also exhibited high concentrations of Fe, Mn and humic substances. 234,238 U was present entirely in soluble form in all waters, probably as uranyl ion (UO 2 2+ ) in soluble carbonate complexes. 226 Ra was in soluble form in the waters with low concentrations of Fe and Mn, but 10% of the total 226 Ra activity was bound to particles in the Fe-Mn-rich waters. The behaviour of Po varied with water composition. Particle-bound 210 Po was observed to correlate with the combined concentration of iron and manganese in the raw waters. In the two of waters of Na-Cl type, in which the concentrations of Fe, Mn and humic substances were high, salinity of the waters did not enhance the solubility of polonium. Polonium was present in both soluble and particle-bound forms in all the ground waters.