A CaCl2 10.8, NaCl 5.35, and SO4 0.037% soda-ash process waste brine, pH 7, was treated 0.5-1 h (optimum similar to45 min) at 60degreesC in a 63-mL glass-PTFE agitated reactor (Fig. 1) with 18-34 g/L adsorbent containing hydrated Zr oxide to reduce the SO4 to 0.002%. The ion-exchange adsorbents prepared by fusing (1) Australian-grade Zr silicate and (2) tech.-grade zirconia with NaOH, were 196 and 1.7 mum in particle size, resp., and the minimum amounts ensuring the required desulfation degree were (1) 34 and (2) 26 gl L. The pH of the brine, adjusted with 1.4-2.2 g HCl/kg, was optimum at 2.2 (Fig. 2). Desorption was followed by a hot condensate (90degreesC) wash. After 7 and 3 regeneration runs of ion-exchangers (1) and (2) with aq. NaOH, the adsorption efficiency fell by 2-3%. The small particle size of (2) resulted in low filtration efficiency. This nontoxic, no-waste process involving simple and efficient regeneration and lower consumption of adsorbents, is superior to the critically evaluated conventional precipitation of toxic BaSO4 with BaCl2.