Application of TiO 2 /perlite photocatalysis for degradation of ammonia in wastewater Y. Shavisi a , S. Sharifnia a, *, S.N. Hosseini b , M.A. Khadivi a a Catalyst Research Center, Chemical Engineering Department, Razi University, Kermanshah 67149-67246, Iran b Research and Production Complex, Pasteur Institute of Iran, Tehran, Iran 1. Introduction Ammonia is a useful chemical material in the manufactures and industrial plants. However, it is a common material in industrial effluents and when it’s released into rivers in excess amounts, causes noticeable effects on fishes and human health [1]. It attacks the breathing system, skin, and eyes, and at a concentration higher than 300 ppm might lead to death [2,3]. Different technical methods were applied to remove ammonia from industrial wastewater, such as biological treatments [4], chemical precipitation [5], advanced oxidation processes [6], air stripping [7], ion exchange [8], adsorption [9], membrane [10], and photocatalytic processes [1,11–15]. The photocatalytic degradation of various toxic compounds has been proposed as a practical method in the decontamination of wastewater for renewable use [16–18]. Meanwhile, titanium dioxide (TiO 2 ) has been widely used as a photocatalyst due to its ability to oxidize toxic substances into nontoxic substances in polluted aqueous systems [19–21]. So far, the use of TiO 2 nanoparticle structures on the photocatalytic degradation of ammonia has been reported by several researchers [1,11–15]. The photodegradation of ammonia using TiO 2 catalyst reveals that this photochemical reaction treats the ammonia into harmless N 2 and H 2 gases [22]. The photocatalytic oxidation using titanium (IV) oxide is activated by ultraviolet (UV) light irradiation (Eq. (1)) [15]. TiO 2 þ h v ! h þ þ e  (1) In photocatalytic reactions, the generated hole (h + ) and electron (e  ) play a main role. Also, the hydroxyl produced from the decomposition of water (Eq. (2)) facilitates ammonia oxidation to N 2 (Eqs. (3) and (4)) or to NO 3  (Eq. (5)) [11]. It seems that the main difference, between the two mechanisms is in the final products. h þ þ H 2 O ! H þ þ  OH (2) NH 3 !  OH NH 2 þ H 2 O !  OH NH þ H 2 O !  OH N þ H 2 O (3) NH x þ NH y ! N 2 H xþy ! H þ N 2 ðx;y¼0;1;2Þ (4) NH 3 !  OH HONH 2 !  OH NO  2 ! NO  3 (5) The process of separation is inevitable by considering nano- sized TiO 2 particles in the photocatalytical reactor [11,13,21]. However, the application of techniques to eliminate the separation process that reduces costs and simplifies the wastewater treatment system has been considered by researchers. In this area many techniques have been applied for solving this problem with immobilizing TiO 2 catalysts onto a suitable solid inert Journal of Industrial and Engineering Chemistry xxx (2013) xxx–xxx A R T I C L E I N F O Article history: Received 19 September 2012 Accepted 25 March 2013 Available online xxx Keywords: Wastewater Ammonia Photocatalyst TiO 2 Perlite A B S T R A C T The purpose of this study was removal of ammonia by a new photocatalytic process from synthetic wastewater under UV irradiation. TiO 2 was used as the photocatalyst and immobilized on perlite granules as a supporter. The prepared catalysts were characterized by SEM and FTIR analysis showed that TiO 2 /perlite catalyst has mesoporous structures and uniform coating of TiO 2 on support. Also, the optimum efficiency of photocatalytical degradation of ammonia was obtained at pH 11 for UV intensity irradiation with 125 W lamp. About 68% degradation of ammonia in wastewater was achieved after 180 min of irradiation by using the optimized reaction conditions. ß 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved. * Corresponding author. Tel.: +98 831 4274535 9 284; fax: +98 831 4274542. E-mail addresses: sharif@razi.ac.ir, ssharif_99@yahoo.com (S. Sharifnia). G Model JIEC-1303; No. of Pages 6 Please cite this article in press as: Y. Shavisi, et al., J. Ind. Eng. Chem. (2013), http://dx.doi.org/10.1016/j.jiec.2013.03.037 Contents lists available at SciVerse ScienceDirect Journal of Industrial and Engineering Chemistry jou r n al h o mep ag e: w ww .elsevier .co m /loc ate/jiec 1226-086X/$ – see front matter ß 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jiec.2013.03.037