Techno-economic preferability of cost-performance effective draw solutions for forward osmosis and osmotic anaerobic bioreactor applications

Abstract

Cost and performance efficient integrations of biological treatments with membrane processes are very worthy for water and resource recovery among of which osmotic anaerobic digestion suffers from exactly elucidating desirable techno-economic features of key operating factors. Cost-performance effective draw solutions (DSs) were ascertained for forward osmosis (FO) and its anaerobic bioreactor (AnBR) configurations, anaerobic osmotic membrane bioreactor (AnOMBR) and [FO/AnBR]. In case study comprising literature data pre-screening, selected DS experiments, and preferability analysis, dual modeling was executed for prioritizing DSs eligible to osmotic AnBRs by analytic hierarchy process (AHP). Through AHP screening of 29 DSs' FO data, NaNO3, NaCl, MgCl2, CaCl2, NH4H2PO4, HCOONa and CH3COONa were established between the best 10% worth researching for osmotic AnBRs. Experiments showed that isothermally varied temperatures hardly affected DS performances in submerged, but DS concentration raises led to those distinguished by reverse solute fluxes. Reverse solute flux selectivity was differed significantly by DS kinds and FO configurations because of varying interactions among predominant inorganic ion and soluble organics. Submerged FO fed by distilled water provided better performance than sidestream but not by wastewater. Anaerobic bioactivities showed longer acclimation times increased by alkalinity unlike seawater (SW) and better CH4 productivity of organics enhanced by DS concentration. Upon AHP analyses, CaCl2, MgCl2, both organics, and SW were more techno-economically favorable DS kinds. Irrespective of technological alternatives, CaCl2 and MgCl2 were found as top two except just SW was the best for AnOMBR by low-cost supply. It was finally proved that eligible DSs should be designated technology dependently due to their distinctive performances and replenishment costs, and topmost priority to SW should be attributed in sustainable wastewater reclamations by AnOMBR in coastal countries.