Integration of Forward Osmosis Membrane Bioreactor (FO-MBR) and Membrane Distillation (MD) units for water reclamation and regeneration of draw solutions

In the current lab scale study, two treatment technologies of FO (Forward osmosis) and DCMD (Direct contact membrane distillation) were used in combination to create a continuous system for water reclamation using, inorganic NaCl, surfactant (Tetraethyl ammonium bromide, TEAB) polyelectrolyte (Polydiallyldimethylammonium chloride, PDAC) as draw solutes with both DI (FO-MD), monoculture municipal synthetic wastewater Bacillus subtillis inoculum feed (FOMBR-MD). Each units was optimized separately at bench scale, then combined form Forward Osmosis Membrane Bioreactor – Distillation (FOMBR-MD) hybrid from wastewater. this system, diluted solution fed MD unit reconcentration. The tested various operating temperatures; FO-MD, temperature difference 15 °C chosen, 35 permeate 20 °C. For FOMBR, increased 25 When cross flow velocity kept constant, flux significantly increasing temperature. Low grade waste heat industry can potentially be utilised FO-MD process. increase higher NaCl TEAB (60–80 %) when compared PDAC (20–50 %), A greater turbulence channel, flux. Up 60 % observed 0.12 0.17 m/s, while not high 0.21 m/s thus chosen cross- MD. Higher concentrations tended reduce vapour pressures hence decreased fluxes. FO-MBR well balanced lower molecular weight solutes, but fluxes (TEAB, PDAC). This imbalance reflected their diffusivities tendencies toward concentration polarization. Reverse solute transport (RST) values leading salinity or toxicity by observations, therefore it feasible run an FOMBR-MD Hybrid extended times. However, decline versus time than TEAB. showed lowest most stable flux, lesser fouling tendency that Overall, enabled pure production non-volatile component rejection nearly 99 %, RST <0.1 GMH solutions back much permeate. other low are recommended stability priorities where reverse (RST), MBR tank, is issue. such PDAC, less critical sensitivity microbial consortium concern. all cases, some degree process control order bring systems more quickly state; periodic cleaning deemed necessary maintain state.