Characterization of electrospun polystyrene membrane for treatment of biodiesel's water-washing effluent using atomic force microscopy

• Published in: Desalination Vol. 329; pp. 1 - 8
• Main Authors: Shirazi, M.M.A., Kargari, A., Bazgir, S., Tabatabaei, M., Shirazi, M.J.A., Abdullah, M.S., Matsuura, T., Ismail, A.F.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.11.2013; Elsevier
• Subjects: Adsorption; Applied sciences; Atomic force microscopy; Biodiesel; Chemical engineering; desalination; Electrospinning; Exact sciences and technology; Filtration; General purification processes; hydrophobicity; Liquid-liquid and fluid-solid mechanical separations; Membrane; Pollution; polystyrenes; roughness; screening; surface roughness; topography; Treatment; Washwater effluent; wastewater; Wastewaters; Water treatment and pollution; Washwater effluent; Electrospinning; Atomic force microscopy; Membrane; Treatment; Biodiesel; Filtration; Porous membrane; Roughness; Washing; Hydrophobicity; Waste water; Pore size; Microporosity; Adsorption; Heating; Chemical oxygen demand; Morphology; Topography
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2013.08.019

The application of atomic force microscopy (AFM) for characterization of electrospun microporous membranes was assessed. The surface roughness, pore size and its distribution, nodule size as well as fiber diameter were analyzed for an electrospun polystyrene membrane before (M1) and after surface modification via contact-heating (CH) method (M2). It was found that thermal modification has improved the overall surface morphology and topography, exhibiting a decrease in mean pore size and nodule size, lowering roughness parameters, which led to more uniform and circular pore geometry, and higher hydrophobicity. As a result, separation performance was improved when the membranes were used for the treatment of biodiesel's wash water effluent. It was also observed that both membranes were effective in treating the highly polluting saponified wastewater. In particular, the application of M1 resulted in the reduction rates of 58, 26, 92, 95 and 50%, respectively, for COD, BOD, TS, TDS and TSS. More promising reduction rates were achieved with M2, where those of COD, BOD, TS, TDS and TSS were at 75%, 55%, 92%, 96% and 30%, respectively. The multi-objective separation mechanism of electrospun membranes (screening, depth filtration and adsorption), could be the cause of their superior separation performance. •Investigating the effect of thermal modification on the ES membrane's morphology.•Comprehensive characterization of the electrospun membranes using AFM.•Using CH led to decease the membranes roughness whilst increased the hydrophobicity.•Application of electrospun membranes for biodiesel's washwater effluent.•Considerable COD and BOD removals (75 and 55%, respectively) were achieved.