Behaviours of poly(ε-caprolactone)/silver-montmorillonite nanocomposite in membrane ultrafiltration for wastewater treatment

• Published in: Environmental technology 2020-07, Vol.41 (16), p.2049-2060
• Main Authors: Benhacine, Fayçal, Abdellaoui, Naima, Arous, Omar, Hadj-Hamou, Assia Siham
• Format: Article
• Language: English
• Subjects: Antiinfectives and antibacterials; Bentonite; Bicarbonates; Cadmium; Coliforms; Contact angle; E coli; Electric contacts; Electrical resistivity; Heavy metals; Lead; membrane ultrafiltration; Membranes; Metal Nanoparticles; Montmorillonite; nanocomposite; Nanocomposites; Nanoparticles; Nitrates; Poly(ε-caprolactone); Polycaprolactone; Polyesters; Scanning electron microscopy; Silver; silver-montmorillonite nanoparticles; Solid suspensions; Surface properties; Total suspended solids; Trace elements; Trace metals; Ultrafiltration; Waste Water; Wastewater treatment; water purification; Water treatment; Zinc
• ISSN: 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2018.1555283

The scope of this work consists in studying the possibility of using the long-lasting antimicrobial poly(ε-caprolactone)/silver-montmorillonite (PCL/Ag-MMT) materials which we have developed in our previous research, as new class of nanocomposite membranes, finding their application in the wastewater treatment. The surface properties of these hybrid membranes were investigated by scanning electron microscopy (SEM) analysis and contact angle measurements. The SEM results showed that the synthesized membranes exhibited homogeneous sponge microstructures. It was found that the gradual inclusion of nanoparticles (2, 3 and 5 wt. %) into PCL matrix induced a remarkable increase of the membrane thickness. Moreover, these hybrid materials exhibited an enhancement of the surface hydrophilicity attributed to the hydrophilic nature of clay incorporated. The water contact angle of the PCL membrane surface noticeably decreased after the Ag-MMT addition: dropping from 82.60° for PCL 0%Ag-MMT to 64.28° for PCL 5%Ag-MMT membrane. The antimicrobial properties of the membranes were confirmed using Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) as the model bacteria. Quality parameters including total suspended solids (TSS), electric conductivity (EC), nitrates, chlorides, bicarbonates, heavy metals and other trace elements, were determined before and after treatment of real wastewater. A decrease of nitrates by 15.12%, a diminution of sulphates by 45.61% and a removal of 41.38%, 53.57% and61.11% for heavy metals Pb, Zn and Cd respectively indicating clearly that the ultrafiltration process using PCL/AgMMT nanocomposite membranes is an effective way to eliminate the wastewater effluents.