Development of Copper-Aluminum Layered Double Hydroxide in Thin Film Nanocomposite Nanofiltration Membrane for Water Purification Process.

Muhammad Hanis Tajuddin,Ahmad Fauzi Ismail,Nor Faizah Razali,Norhaniza Yusof,Kazukiyo Nagai,Wan Norharyati Wan Salleh,Farhana Aziz,Ihsan Wan Azelee,Juhana Jaafar

doi:10.3389/fchem.2019.00003

Abstract

This study aims to fabricate a thin film composite (TFC) membrane, modified with copper-aluminium layered double hydroxide (LDH) nanofillers via interfacial polymerization technique for nanofiltration (NF) processes. It was found that Cu-Al LDH nanofillers possessed layered structured materials with typical hexagonal plate-like shape and positive surface charge. The study revealed that TFN membrane exhibits a relatively smooth surface and a less nodular structure compared to pristine TFC membrane. The contact angle of TFN progressively decreased from 54.1° to 37.25°, indicating enhancement in surface hydrophilicity. Moreover, the incorporation of LDH nanofillers resulted in a less negative membrane as compared to the pristine TFC membrane. The best NF performance was achieved by TFN2 membrane with 0.1° of Cu-Al LDH loading and a water flux of 7.01 Lm-2h-1.bar. The addition of Cu-Al LDH resulted in excellent single salt rejections of Na2SO4 (96.8%), MgCl2 (95.6%), MgSO4 (95.4%), and NaCl (60.8%). The improvement in anti-fouling properties of resultant TFN membranes can be observed from the increments of pure water flux recovery and normalized water flux by 14% and 25% respectively. The findings indicated that Cu-Al LDH is a promising material in tailoring membrane surface properties and fouling resistance. The modification of the LDH-filled TFN membrane shows another alternative to fabricating a high-performance composite membrane, especially for water softening and partial desalination process.

Highlights

Global water scarcity has affected people in the twentyfirst century as the present water resource is insufficient to provide enough clean water, especially in the urban and waterstressed region
The successful fabrication of thin film nanocomposite membranes (TFN) membranes could indicate the potential of nanofillers in water separation processes
The CuAl layered double hydroxide (LDH) were synthesized based on co-precipitation methods

Summary

Introduction

Global water scarcity has affected people in the twentyfirst century as the present water resource is insufficient to provide enough clean water, especially in the urban and waterstressed region. With the latter problem address previously, technologies such as membrane separation process has serve as one of the alternatives to overcome this issue. The fabrication of thin film composite (TFC) membrane by interfacial polymerization has provided significant advantages owing to its unique structures such as ultra-thin selective layer and porous substrate of TFC membrane Both layers [polyamide (PA) thin layer and substrate layer] can be independently optimized and controlled to achieve desired selectivity while retaining the excellent mechanical strength and compression resistance. These intrinsic properties allow the fabricated TFC membrane to achieve high water flux and salt rejection

Objectives

Methods

Results

Conclusion