The water recycling scheme foreseen in the REWATCH project includes a final step using ion exchange resins aimed at removing trace ions. The aim of this polishing step after is achieve a water effluent fulfilling quality specifications for boiler feed water. Water demand for boilers accounts for the 8% of the total water consumption in DOW but quality requirements are extremely strict.
Experiments at bench-scale have been performed in CTM laboratories to simulate the ion exchange process, using resins manufactured by DOW. The experiments consisted on the evaluation of the column effluent composition and quality under different test conditions. To date, water qualities achieved during the operation of the system are promising.
For more information about this technology http://www.dow.com/en-us/water-and-process-solutions/products/ion-exchange-resins/dowex-marathon-ion-exchange-resins