Removal of beta blockers using polyelectrolyte monolayered membrane and its antifouling performance

Abstract

Surfaces of commercially available polyamide membranes were modified by polyelectrolyte monolayer by dip coating method. The formation of monolayered membranes was confirmed by spectroscopic and microscopic methods. The membrane performance is evaluated for the removal of beta blockers (β-blockers) from aqueous solution and resulted in nearly complete (98%) removal. Also, in presence of ions, surfactant and humic acid above 85% of removal was observed. For atenolol (ATL), metoprolol (MPL) and timolol (TML) the rejection was very poor at acidic pH values and from pH 6 onwards nearly complete removal was observed. The removal percentage was unaltered for propranolol (PPL) and labetalol (LTL). A reduction in rejection percentage was observed for PPL (42%) and LTL (17%) respectively as the concentration of the salt increases from 0M to 0.2M while the others were almost completely permeated. The adsorbed β-blockers could be desorbed from the membrane (ATL (86%), MPL (93%), TML (83%), PPL (44%) and LTL (32%)). The performance of the membrane was also evaluated by continuously exposing it to the feed solution. The removal was found to be decreasing on increasing the feed volume at steps. The performance was further improved by the inclusion of chitosan/poly(styrene sulfonate) (CHI/PSS) multilayers.