Contribution of boron specific resins co

Permeable reactive barrier (PRB) column tests for removal of borate were carried out over 287 days corresponding to 76 pore volumes (PV), using MgO agglomerates as the primary reactive material, with and without boron-specific resin (CR805). Adding 3 (w %) CR805 increased the column shelf life (the time until effluent contains the maximum boron concentration for drinking water) by about 50%, and increased boron accumulation within the column by 15% over 76 PV. The quantities of boron captured were 15–17 mg/g-CR805, and 1–2 mg-B/g-MgO, decreasing with increasing distance along the column. Refined refinement of X-ray diffraction patterns from solid residues after 76 PV revealed that 69-78% of the MgO was transformed into Mg(OH)2 independent of distance along the column, implying that hydration of MgO is not always associated with integration of borate. 11B-NMR spectra demonstrated that trigonal B (18B) is predominantly immobilized in M(OH)2 in both columns, while tetragonal B (14B) is largely trapped in the added CR805. The complexed forms of 14B with the N-methylglucamine group after 76 PV were mostly bischelate.