41-OR: The DQ dichotomy; to V or not to V (virtual XM)

Evaluation of direct osmosis high salinity (DO-HS) method by nitrate salts as draw solution in fouled RO membrane cleaning

“…Chemical method is an effective method to remove foulants, but this method, resulting in process downtime and membrane degradation, has also increased operation costs and requires stopping the RO plant operation [9]. Recently the new DO-HS technology offered a novel backwash approach for on-line membrane cleaning in RO operation without stopping the RO pump [10,11]. There was no interruption of RO operation in a new DO cleaning technology development where a high salinity solution (HS) was injected into the feed water for certain time that could induce multiple cleaning mechanisms composed of fouling lifting and sweeping as well as bio-osmotic shock and salt dissolve shock, thus could provide high cleaning efficiency [12].…”

“…Even with seemingly appropriate pretreatment processes in place, full-scale NF and RO system can suffer from bio fouling and scaling, which increase applied pressure (such as energy and cost) and limit product water recovery, respectively. Therefore, fouling control at real NF and RO plants has been a decade's long battle despite exhaustive efforts to improve the membrane and module properties, optimize pretreatment processes, and improve the chemical cleaning agents [1,2].…”