Practical considerations for operability of an 8″ spiral wound forward osmosis module: Hydrodynamics, fouling behaviour and cleaning strategy

Abstract

A better understanding of large spiral wound forward osmosis (SW FO) module operation is needed to provide practical insight for a full-scale FO desalination plant. Therefore, this study investigated two different 8" SW FO modules (i.e. cellulose tri acetate, CTA and thin film composite, TFC) in terms of hydrodynamics, operating pressure, water and solute fluxes, fouling behaviour and cleaning strategy. For both modules, a significantly lower flow rate was required in the draw channel than in the feed channel due to important pressure-drop in the draw channel and was a particularly critical operating challenge in the CTA module when permeate spacers are used. Under FO and pressure assisted osmosis (PAO, up to 2.5 bar) operations, the TFC module featured higher water flux and lower reverse salt flux than the CTA module. For both modules, fouling tests demonstrated that feed inlet pressure was more sensitive to foulant deposition than the flux, thus confirming that FO fouling deposition occurs in the feed channel rather than on the membrane surface. Osmotic backwash combined with physical cleaning used in this study confirmed to be effective and adapted to large-scale FO module operation.

Forward Osmosis Application in Manufacturing Industries: A Short Review

“…Pilot-scale investigations are necessary to prove the technical practicability of forward osmosis. One pilot-scale plant, which is shown in Figure 8 , is operated by the working group of Prof. Shon in Sydney [ 51 , 52 ]. The overall layout is similar to the one for the lab-scale experiments.…”

“…The FO modules are operated in parallel. Different FO membrane modules have been used: two CTA FO modules from HTI (20.2 m 2 ) [ 51 ], CTA FO module from HTI (9 m 2 ) [ 52 , 53 ], TFC FO module from Toray Chemical Korea Inc. (15 m 2 ) [ 52 ]. …”

“…They are (in alphabetical order): Aquaporin A/S (Kongens Lyngby, Denmark) [ 66 , 67 ], Aquaporin Asia Pte. Ltd. (Singapore) [ 68 , 69 ], BLUE-tec BV (Renkum, The Netherlands) [ 56 , 70 ], Darco Water Technologies Ltd. (Singapore) [ 71 , 72 ], De.mem Ltd. (Singapore) [ 73 ], Fluid Technology Solutions, Inc. (FTS, Albany, OR, USA) [ 74 ], Hydration Technology Innovations, LLC (HTI, Albany, OR, USA)—meanwhile out of business [ 52 ], Modern Water plc. (London, UK) [ 62 , 63 , 64 ], Oasys Water, Inc. (Cambridge, MA, USA) [ 75 , 76 ], Porifera, Inc. (Hayward, CA, USA) [ 55 ], Toray Chemical Korea, Inc. (Seoul, Korea) [ 52 ], Trevi Systems, Inc. (Petaluma, CA, USA) [ 77 ], W.O.G.…”

A review of efforts to reduce membrane fouling by control of feed spacer characteristics

“…Kim et al [79] investigated two spiral wound forward osmosis modules containing cellulose tri-acetate and thin film composite membranes, in terms of hydrodynamics, fouling behaviour and cleaning strategy. For both modules, a 5-times lower flow rate was demanded in the draw than needed in the feed channel, attributable to significant pressure drop in the draw channel, and was a remarkably critical operating challenge in the cellulose tri-acetate module when permeate spacers were employed.…”

Short Communication: Requiring Reverse Osmosis Membranes Modifications – An Overview

“…They degrade membrane efficiency and decrease its life span [115]. Consequently, membranes require to be changed usually conducting to elevated operating costs [116]. The great reason of fouling is the elevated pressures implicated in RO [4,[117][118][119].…”