Porosity Effect of Polystyrene Membranes on Desalination Performance: A Combined Experimental and Numerical Heat and Mass Transfer Study in Direct Contact Membrane Distillation

Abstract

Membrane distillation (MD) is a thermal-based membrane operation with high potential for use in the treatment of aqueous streams. In this study, the linear relationship between the permeate flux and the bulk feed temperature for different electrospun polystyrene membranes is discussed. The dynamics of combined heat and mass transfer mechanisms across different membrane porosities of 77%, 89%, and 94%, each with different thicknesses, are examined. The main results for the effect of porosity with respect to the thermal efficiency and evaporation efficiency of the DCMD system are reported for electrospun polystyrene membranes. A 14.6% increase in thermal efficiency was noted for a 15% increase in membrane porosity. Meanwhile, a 15.6% rise in porosity resulted in a 5% increase in evaporation efficiency. A mathematical validation along with computational predictions is presented and interlinked with the maximum thermal and evaporation efficiencies for the surface membrane temperatures at the feed and temperature boundary regions. This work helps to further understand the interlinked correlations of the surface membrane temperatures at the feed and temperature boundary regions with respect to the change in membrane porosity.

Solar desalination with charcoal briquettes from plants as an additional absorption sorbent

“…The difference in charcoal types lies in the porosity of each charcoal. This porosity affects the absorption of sunlight, and the wider the porosity of the charcoal, the higher the evaporation efficiency [45].…”

Salt resistant and self‐cleaning CNTs‐SEBS‐MAH composite membrane for seawater desalination

“…14 Graphene thin films tend to excessively swell in water, and the mechanical properties within the film's large pores are compromised, leading to poor stability. 15,16 Meanwhile, due to the two-dimensional lamellar structure of graphene, the vapor circulation is poor during the vapor-phase pore-forming process, and it is not easy to form pore structures. 17,18 Thus, polymer composite materials incorporated with CNTs have proved to be efficient solar evaporation agents, such as CNTs-containing hydrogel systems and CNTs-containing thermoplastic composites.…”