Mixed-bed systems comprising both strong-acid (cation) and strong-base (anion) ion exchange (IEX) resins can be used for the removal of salts to produce drinking quality water from saline feedwater. In this study, complete regeneration in situ was achieved by washing with concentrated ammonium bicarbonate (AB) solution, which produces complete regeneration of the mixed resins, without the need for their separation. This process was found to be more effective than regeneration with AB using a resin heat-decomposition process, previously studied. The results presented here show that a mixed-bed resin can desalt 0.1 M NaCI solution, producing about 6 Chi the resin mass of drinking quality water, The resin can then be regenerated using concentrated AB and then reused again to remove NaCI, producing ammonium bicarbonate solution. The product AB solution can then be readily converted into drinking water (DW) simply by heating to 60-80 degrees C or by using a recently developed bubble column evaporator (BCE) process or by using multiple distillation columns (MDC). These processes decompose the AB solution to both produce drinking water product and gaseous NH3 and CO2, which can then be collected and used to re-form the AB solution. In this way the resin can be regenerated in a continuous process, without the need for further acid and base consumption, minimizing chemical waste, environmental impact, and costs. (C) 2017 Elsevier B.V. All rights reserved.