Development of hybrid electrodialysis-reverse osmosis domestic desalination unit for high recovery of product water

Reverse osmosis (RO) membrane-based domestic water desalination/purification units have gained wide acceptance even in India. Unfortunately, the recovery of product water from these units varies between 10 and 20% depending on total dissolved solid (TDS) of the feed water. Problem of tap water salinity is increasing, because of ground water depletion. Also, low recovery of product water during desalination is a serious problem, in view of water scarcity. In this manuscript, we are reporting electrodialysis (ED)-RO hybrid process for high recovery of product water from brackish water without compromising on water quality (Indian Patent Application No. 1418/DEL/2010). In hybrid process, ED unit was operated in high TDS region (low system resistance and thus high efficiency), and RO system operated in low TDS region, to reduce salinity load on membrane.