Delivered by Ingenta to: McMaster University IP: 188.68.1.41 On: Thu, 16 Jun 2016 16:13:34 Copyright: American Scientific Publishers RESEARCH ARTICLE Copyright © 2013 American Scientific Publishers All rights reserved Printed in the United States of America Journal of Nanoscience and Nanotechnology Vol. 13, 4106–4109, 2013 Preparation of Iron-Doped Titania from Flocculated Sludge with Iron-Titanium Composite Coagulant Jong Beom Kim 1 2 , Ki Won Lee 2 , Se Min Park 1 , Ho Kyong Shon 3 , Mohammad Shahid 3 , Ibrahim El Saliby 3 , Woong Eui Lee 4 , Geon-Joong Kim 5 , and Jong-Ho Kim 1 2 ∗ 1 School of Applied Chemical Engineering, Chonnam National University, Gwangju 500-757, Korea 2 Photo and Environmental Technology Co. Ltd., Gwangju 500-460, Korea 3 School of Civil and Environmental Engineering and CRC CARE, University of Technology, Sydney UTS, P. O. Box 123, Broadway, NSW 2007, Australia 4 Kwang Ju Women’s University, Gwangju 506-713, Korea 5 Department of Chemical Engineering, Inha University, Incheon 402-751, Korea The main drawback of flocculation process with dye wastewater is the large amount of unrecy- clable sludge which needs disposal. A novel process using Ti-salt flocculation to purify wastewater was developed to produced sludge that can be calcined to produce titania. In this study, iron- doped TiO 2 nanomaterial was successfully produced from sludge obtained by the flocculation of dye wastewater with a composite floculant including TiCl 4 and FeSO 4 . The titania was charac- terised using scanning electron microscopy (SEM/EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), and the photodecomposition of acetaldehyde. The XDR results showed that the anatase and rutile structures were found after sludge calcination at 550  C and 640  C respectively. The elemental analyses were carried out using EDX. The rutile titania sample con- sisted of Ti (35.7 wt.%), Fe (14.7 wt.%), O (42.3 wt.%), P (2.6 wt.%) and Ca (4.7 wt.%). The photocatalytic activity was monitored for the photodecomposition of gas acetaldehyde. Iron-doped titania seems to play an important role in increasing the photocatalytic activity under UV light irradiation. Keywords: Flocculation, Sludge, TiO 2 , Photocatalysis, Acetaldehyde. 1. INTRODUCTION Flocculation is a chemical treatment method for treating a wide range of wastewaters by removing suspended solids and organics. Aluminum sulphate, iron salt and polyalimu- nium chloride are common flocculants acting by destabiliz- ing the colloidal materials and causing the small particles to agglomerate into larger settleable flocs called sludge. But, the main drawback of flocculation process is the production of large amount of unrecyclable sludge which needs disposal. Disposal of sludge is often environmentally problematic and costly. A novel process using Ti-salt flocculation to purify wastewater was developed to produce sludge that can be calcined to produce titania nanomaterials. 1 Recently, Iron (Fe) has been used to dope TiO 2 and its photocatalytic activity was superior to the commercial ∗ Author to whom correspondence should be addressed. Degussa P-25 under visible light irradiation. 2 3 Optimum photocatalytic properties were achieved upon doping at a relatively weak level. Fe ions trapped not only electrons but also holes, which lead to increase of photoactivity. The maximum photoactivity appeared with 0.5 wt% of Fe 3+ due to the decrease in the density of the surface active centres. 4 To the best of our knowledge, no stud- ies have been made on the flocculation of dye wastewater using TiCl 4 coagulation together with FeSO 4 to produce Fe-doped TiO 2 nanomaterials. In this study, dye wastewater flocculation using com- posite coagulant including TiCl 4 and FeSO 4 was carried out to produce iron-doped titania. The objectives of this study was to investigate the performance of iron-titanium composite coagulant with dye wastewater and to charac- terise Fe-doped TiO 2 nanomaterials in terms of scanning electron microscopy (SEM/EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), and the pho- todecomposition of acetaldehyde. 4106 J. Nanosci. Nanotechnol. 2013, Vol. 13, No. 6 1533-4880/2013/13/4106/004 doi:10.1166/jnn.2013.7017