Method of treatment of produced water and recovery of important divalent cations

A method of removing radium and recovering barium and strontium salts from contaminated wastewater, the method comprising the steps of:

• a. providing a feed wastewater containing metal cations including radium and at least one of barium or strontium;
• b. contacting the feed wastewater with a bed of a polymeric cation exchanger resin, the resin including barium sulfate salts, to thereby cause the radium in the wastewater to be adsorbed by the resin and produce a first effluent that is lower in radium than the wastewater, the first effluent optionally containing cations of any of calcium, magnesium, barium and strontium;
• c. optionally processing the first effluent to create a second effluent that is characterized by the presence of divalent cations selected from any of calcium, barium, and strontium;
• d. if the first effluent or second effluent contains barium, contacting the first or second effluent with at least one barium-removing bed comprising an acidic cation exchange resin having negatively charged fixed functional groups thereon until breakthrough of barium is detected, to thereby yield a third effluent having a lower barium content than the first effluent or second effluent;
• e. optionally, subsequent to step 1(d), contacting the barium-removing bed with a solution containing a soluble salt of barium until breakthrough of barium is detected to provide a fourth effluent;
• f. if the third or fourth effluents contain strontium, contacting the third or fourth effluents with a strontium-removing cation exchange bed until breakthrough of strontium is detected to yield a fifth effluent, the fifth effluent having less strontium content than the third or fourth effluents;
• wherein, upon completion of steps a-f, the first effluent, second effluent, third effluent, fourth effluent, and fifth effluent collectively contain less than 10% of the amount of any radium, barium, or strontium present in the feed wastewater.