Phenol rejection by cellulose triacetate and thin film composite forward osmosis membranes

Abstract

This study aims to elucidate the separation of phenol by reverse osmosis (RO) and forward osmosis (FO) modes and propose strategies to enhance phenol rejection by these two processes. The results show that phenol rejection was strongly influenced by water flux, membrane materials, membrane structure, modes of operation, and feed solution chemistry (i.e. pH). The relationship between phenol rejection and water flux was demonstrated by the irreversible thermodynamic model which could accurately simulate phenol rejection as a function of water flux. At pH 7, phenol rejection by cellulose acetate (CTA) membranes was negligible while the thin film composite (TFC) polyamide (PA) membranes exhibited much higher phenol rejection. Through a systematic static adsorption experiment, results in this study show that phenol adsorption to CTA material was about 20 times higher than that to PA material. Thus, the observed higher phenol rejection by TFC PA compared to CTA membranes was attributed to the significantly higher affinity of phenol toward CTA and the sorption diffusion transport mechanism of phenol through the membrane. In particular, a TFC PA membrane specific for FO operation was prepared in this study. In FO mode, the tailor-made TFC PA membrane showed a slightly higher phenol rejection and a much higher water permeability compared to the commercial membrane. At the same water flux and solution pH, phenol rejection in FO mode was consistently higher than in RO mode. This observation could possibly be attributed to the reverse diffusion of draw solutes in the FO mode which hinders the forward diffusion of phenol through the membrane. A significant increase in phenol rejection was achieved by increasing the feed pH above the dissociation constant of the compound.

Forward Osmosis Application in Manufacturing Industries: A Short Review

“…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.…”

“…Another study investigated the rejection of phenol by different forward osmosis membranes [ 74 ]. The FS was an artificial wastewater from oil and gas industry.…”

Performance Improvement and Biofouling Mitigation in Osmotic Microbial Fuel Cells via In Situ Formation of Silver Nanoparticles on Forward Osmosis Membrane

“…In order to avoid the diminishing of the CTA-FO membrane property modified by AgNPs, we intend to prepare the AgNP modified FO membrane using the thin film composite (TFC) polyamide FO membrane according to the following two reasons. Compared with the CTA-FO membrane, the TFC-FO membrane has more potential to be applied in wastewater treatment owing to its higher flux and selectivity, better pH stability, and resistance to hydrolysis [22][23][24][25]. In addition, AgNPs could be directly coated by sodium borohydride (NaBH 4 ) on the TFC-FO membrane surface due to the presence of carboxyl groups on the membrane surface while AgNPs could not be directly formed on the CTA-FO membrane surface [13,26].…”

Phenol Removal by Novel Choline Chloride Blended Cellulose Acetate-Fly Ash Composite Membrane

“…Phenol is a primary pollutant and it has adverse effects on human health even at very low concentration. Effluents from many industries such as petrochemical, pharmaceutical, printing press, pulp and paper, coke oven contains phenol and its derivatives [1]. The permissible discharge limit for phenol is 0.5 mg•L −1 in effluent as per EPA (2002).…”

“…Membrane separation by composite membranes could be a better alternative due to its high selectivity towards solute, high separation efficiency, ease to handle and energy efficient [10]. Many literatures are reported about fabrication of polymeric-ceramic CM for wastewater treatment [1,10,11]. However, selection of polymeric material to create a suitable active layer is an important and challenging factor.…”