Vibrio neptunius-ULV11 cell-free supernatant as a promising antifouling approach in reverse osmosis systems

One of the most common problems observed in continuous operation of desalination plants, is the presence of biofouling in ultrafiltration (UF) modules and reverse osmosis membranes (ROMs), decreasing permeated water obtention and increasing energy consumption among other adverse effects. To solve this problem, desalination industry applied UF modules and ROMs cleaning procedures that aims to increase half-life operation time, however, many of the actual cleaning procedures are focused on the addition of chemical compounds that provokes secondary effects such as UF modules and ROMs disintegration leading to structural changes and a decrease in plant performance. Thus, new approaches to replace current cleaning compounds with new ecofriendly and less secondary effects technologies are necessary. In this study, we present a Vibrio neptunius strain ULV11 isolate, with a high capacity to remove fouling in RO systems. In detail, ULV11 cell-free supernatant (CFS) was used in replace of chemical agents as a cleaning solution according to standard operational protocol on 3-year-old membranes of continuous operation. The results showed that CFS can be used under operational conditions (such high pressure and flux) allowed us to recover permeate volumes similar to those observed in traditional chemical treatment with better conductivity. This recovery was accompanied by a reestablishment of membrane topology observed by atomic force microscopy and EPS remotion since concanavalin A signal trough confocal microscopy was decrease as compared with biofouling control. •Traditional cleaning agents reduce half-life of ROMs.•New approaches are necessary to cope chemical effects of cleaning solutions.•Bacterial supernatants can be a suitable alternative as an antifouling solution.•CFS-ULV11 is capable to be applied under operational conditions.•Performance of CFS-ULV11 is similar to those observed in traditional treatments.