VATIS UPDATE Article

Researchers from Okayama University, Japan, have found a new technique effective in removing strontium 90 (90Sr) from aqueous solution. The method is based on the hydroxyapatite (HAP) column procedure, which could help remove strontium 90 from water and wastewater. HAP is a major mineral constituent of bone and tooth and has an outstanding biocompatibility. HAP is also a possible sorbent for heavy metals in wastewater due to its high adsorption capacity and low water solubility.

Tests indicated that HAP particles adsorbed more than 90 percent of 90Sr, which was significantly more than tests using zeolite. Calcium ion concentrations of up to 1 millimolar (mM) did not affect its adsorption. 90Sr was also barely affected by the magnesium levels tested. Using a small amount of eluate, the researchers stripped90Sr from the column and regenerated the column for another round of separation.

In addition to removing 90Sr from wastewater, researchers hope the technique will also remove it from natural water in the environment. The concentrated element could also be stored as dry, solid waste, therefore reducing disposal space and lowering costs.