title: Mitigation of Salinity Buildup and Recovery of Wasted Salts in a Hybrid Osmotic Membrane Bioreactor-Electrodialysis System.
abstract: The osmotic membrane bioreactor (OMBR) is an emerging technology that uses water osmosis to accomplish separation of biomass from the treated effluent; however, accumulation of salts in the wastewater due to water flux and loss of draw solute because of reverse salt flux seriously hinder OMBR development. In this study, a hybrid OMBR-electrodialysis (ED) system was proposed and investigated to alleviate the salinity buildup. The use of an ED (3 V applied) could maintain a relatively low conductivity of 8 mS cm(-1) in the feed solution, which allowed the OMBR to operate for 24 days, about 6 times longer than a conventional OMBR without a functional ED. It was found that the higher the voltage applied to the ED, the smaller area of ion-exchange membrane was needed for salt separation. The salts recovered by the ED were successfully reused as a draw solute in the OMBR. At an energy consumption of 1.88-4.01 kWh m(-3), the hybrid OMBR-ED system could achieve a stable water flux of about 6.23 L m(-2) h(-1) and an efficient waste salt recovery of 1.26 kg m(-3). The hybrid OMBR-ED system could be potentially more advantageous in terms of less waste saline water discharge and salt recovery compared with a combined OMBR and reverse osmosis system. It also offers potential advantages over the conventional OMBR+post ED treatment in higher water flux and less wastewater discharge.
authors.affiliation: Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24061, United States.
authors.forename: Yaobin
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24061, United States.
authors.forename: Zhen
authors.initials: Z
authors.lastname: He
mesh_terms: D019149:Bioreactors; D003956:Dialysis / Q000295:instrumentation* / Q000379:methods*; D004560:Electricity; D005240:Feasibility Studies; D005374:Filtration / Q000295:instrumentation; D008567:Membranes, Artificial; D009995:Osmosis; D054712:Salinity; D012965:Sodium Chloride / Q000032:analysis*; D012996:Solutions; D013816:Thermodynamics; D062065:Wastewater / Q000737:chemistry; D018508:Water Purification / Q000295:instrumentation
chemical_list: D008567:Membranes, Artificial; D012965:Sodium Chloride; D012996:Solutions; D062065:Wastewater