Synthesis of crosslinked PVA-ceramic composite membrane for phenol removal from aqueous solution

Abstract

In this study, the thin-film composite membrane (TFCM) was fabricated for phenol–water separation using formaldehyde crosslinked polyvinyl-alcohol (PVA) coating on fly ash-fuller clay ceramic substrate. Thin film was created using 10 % PVA with different concentrations of formaldehyde (1–5 g). The characterization of synthesized membrane such as swelling and chemical stability, permeation study, molecular weight cut off (MWCO), scanning electron microscopy (SEM) and contact angle analysis was carried out to optimize the membrane. The stability of active layer increases with increase in the amount of formaldehyde, whereas the hydrophilicity, degree of swelling, flux and pore size decrease. The smallest pore (1.91 nm) was obtained in the active layer when PVA crosslinked with 3 g formaldehyde (PF3). Phenol–water separation was conducted with PF3 to optimize the process parameters, such as feed concentration, pH and operating pressure. Maximum phenol separation (85 %) was obtained at 207 kPa for 200 mg L-1 of feed phenol. High phenol removal was found at pH 6.0 and thereafter it decreased in alkaline pH. Phenol removal decreased from 80.6 to 19.8 % with the increase in pressure from 207 to 414 kPa, whereas flux increased from 5.3 to 52.38 L m-2 h-1. The results demonstrate that fabricated CM can be successfully used for phenol–water separation.