title: Mathematical modeling based evaluation and simulation of boron removal in bioelectrochemical systems.
abstract: Boron removal is an arising issue in desalination plants due to boron's toxicity. As an emerging treatment concept, bioelectrochemical systems (BES) can achieve potentially cost-effective boron removal by taking advantage of cathodic-produced alkali. Prior studies have demonstrated successful removal of boron in microbial desalination cells (MDCs) and microbial fuel cells (MFCs), both of which are representative BES. Herein, mathematical models were developed to further evaluate boron removal by different BES and understand the key operating factors. The models delivered very good prediction of the boron concentration in the MDC integrated with Donnan Dialysis (DD) system with the lowest relative root-mean-square error (RMSE) of 0.00%; the predication of the MFC performance generated the highest RMSE of 18.55%. The model results of salt concentration, solution pH, and current generation were well fitted with experimental data for RMSE values mostly below 10%. The long term simulation of the MDC-DD system suggests that the accumulation of salt in the catholyte/stripping solution could have a positive impact on the removal of boron due to osmosis-driven convection. The current generation in the MDC may have little influence on the boron removal, while in the MFC the current-driven electromigration can contribute up to 40% of boron removal. Osmosis-induced convection transport of boron could be the major driving force for boron removal to a low level <2mgL(-1). The ratio between the anolyte and the catholyte flow rates should be kept >22.2 in order to avoid boron accumulation in the anolyte effluent.
authors.affiliation: Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
authors.forename: Qingyun
authors.initials: Q
authors.lastname: Ping
authors.affiliation: Department of Chemical Engineering, College of Engineering, Qatar University, P.O. Box 2713, Doha, Qatar.
authors.forename: Ibrahim M
authors.initials: IM
authors.lastname: Abu-Reesh
authors.affiliation: Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA. Electronic address: zhenhe@vt.edu.
authors.forename: Zhen
authors.initials: Z
authors.lastname: He
mesh_terms: D001674:Bioelectric Energy Sources; D001895:Boron / Q000737:chemistry*; D055664:Electrochemical Techniques; D008962:Models, Theoretical; D054712:Salinity; D062065:Wastewater / Q000032:analysis*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods
chemical_list: D001895:Boron; D062065:Wastewater
keywords: Bioelectrochemical systems; Boron removal; Mathematical modeling; Microbial desalination cells; Microbial fuel cells; Water treatment