Cellulose acetate/layered double hydroxide adsorptive membranes for efficient removal of pharmaceutical environmental contaminants

Matei D Raicopol; Corina Andronescu; Stefan I Voicu; Eugeniu Vasile; Andreea M Pandele

doi:10.1016/j.carbpol.2019.03.042

Cellulose acetate/layered double hydroxide adsorptive membranes for efficient removal of pharmaceutical environmental contaminants

Carbohydr Polym. 2019 Jun 15:214:204-212. doi: 10.1016/j.carbpol.2019.03.042. Epub 2019 Mar 14.

Authors

Matei D Raicopol¹, Corina Andronescu², Stefan I Voicu³, Eugeniu Vasile⁴, Andreea M Pandele⁵

Affiliations

¹ University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Polizu 1-7, Bucharest, Romania.
² Chemical Technology III, University Duisburg-Essen and NETZ - Nano Energie Technik Zentrum, CENIDE Center for Nanointegration, Carl-Benz-Straße 199, D-47057 Duisburg, Germany.
³ Advanced Polymer Materials Group, University Politehnica of Bucharest, Polizu 1-7, Bucharest, Romania; Department of Analytical Chemistry and Environmental Engineering, University Politehnica of Bucharest, Polizu 1-7, Bucharest, Romania.
⁴ Univerisity Politehnica of Bucharest, Romania.
⁵ Advanced Polymer Materials Group, University Politehnica of Bucharest, Polizu 1-7, Bucharest, Romania; Department of Analytical Chemistry and Environmental Engineering, University Politehnica of Bucharest, Polizu 1-7, Bucharest, Romania. Electronic address: pandele.m.a@gmail.com.

PMID: 30925990
DOI: 10.1016/j.carbpol.2019.03.042

Abstract

The increasing amount of residual pharmaceutical contaminants in wastewater has a negative impact on both the environment and human health. In the present study, we developed new cellulose acetate/Mg-Al layered double hydroxide (Mg-Al LDH) nanocomposite membranes as an efficient method to remove pharmaceutical substances from wastewater. The morphology, porosity, surface properties and thermal stability of nanocomposite membranes containing various amounts of nanofiller were evaluated by scanning electron microscopy (SEM), X-ray microtomography (μCT), contact angle measurements and thermogravimetric analysis (TGA). The Mg-Al LDH nanofiller showed a high degree of exfoliation in the polymer matrix, evidenced by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The hydrodynamic properties and adsorption capacity were evaluated with pure water and aqueous solutions of two common drugs, diclofenac sodium (DS) and tetracycline (TC), and the nanocomposite membranes showed an improved permeability compared with neat cellulose acetate. The membrane prepared with 4 wt.% Mg-Al LDH loading exhibited the highest water flux compared with the pure polymer one (529 vs 36 L·m^-2·h^-1) and a tenfold increase in adsorption capacity for DS. This enhancement is attributed to electrostatic interactions between the negatively charged drug molecule and positively charged Mg-Al LDH layers. Conversely, in the case of TC, the increase in adsorption capacity was smaller and was assigned to hydrogen bonding interactions between the drug molecule and the nanofiller.

Keywords: Cellulose acetate; Layered double hydroxide; Nanocomposite membrane.