Research Article Comparison of Acid Red 114 Dye Adsorption by Fe 3 O 4 and Fe 3 O 4 Impregnated Rice Husk Ash Gul Kaykioglu and Elcin Gunes Department of Environmental Engineering, Faculty of Corlu Engineering, Namik Kemal University, Corlu, 59860 Tekirdag, Turkey Correspondence should be addressed to Gul Kaykioglu; gkaykioglu@nku.edu.tr Received 29 April 2016; Revised 17 June 2016; Accepted 21 July 2016 Academic Editor: Xingmao Ma Copyright © 2016 G. Kaykioglu and E. Gunes. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te removal of Acid Red 114 (AR114) dye by adsorption process, using the magnetic nanoparticle (RHA-MNP) which is produced from rice husk ash burned at 300 ∘ C and the magnetic nanoparticle (MNP, Fe 3 O 4 ), was studied. Batch processes were used under diferent test parameters: pH (2, 4, 6, and 10) and without pH, initial dye concentration (20, 40, 60, 80, and 100 mg/L), and contact time (0, 1, 5, 10, 15, 30, 45, 60, 90, and 150 min). Optimum conditions for AR114 removal were found to be at natural pH (pH without correction) for both adsorbents. Freundlich isotherm was found to be more consistent for MNP and Langmuir isotherm was found to be more consistent for RHA-MNP. Te maximum adsorption capacities of MNP and RHA-MNP adsorbents for AR114 dye were equal to 111 mg/g. Te kinetic experimental data ftted the pseudo-second-order model for both MNP and RHA-MNP. It can be concluded that RHA-MNP which is a waste could be used as low-cost adsorbent to remove AR114 from aqueous solution. 1. Introduction Dyes are widely used in textile, plastic, food, cosmetics, paper, and carpet industries. Te existence of dyes in the wastewater creates signifcant environmental problems. Dyes resist biodegradation with biological treatment. Coagulation- focculation which includes chemical and physical methods, advanced oxidation processes like Fenton process (H 2 O 2 + Fe +2 ), membrane processes, and electrochemical methods are efective in the removal of dyes. However, these pro- cesses have some disadvantages such as being expensive and producing excessive amount of sludge. Most of the existing processes are adsorption processes, and generally activated carbon (AC) is used as the adsorbent in these processes [1]. Some researchers have investigated the usage of the agricultural wastes as the raw materials to produce activated carbon, which has a high adsorption capacity. In Turkey, the annual average production amount of rice is 700,000 tons. Disposal of rice husks is done in landfll sites, which causes an aesthetic pollution, eutrophication, and problems in aquatic life. Rice husks do not dissolve in water. Tey show silica-cellulose, ligneous, and corrosive characteristics. Te most important materials that compose the internal structure of the rice husk are cellulose, hemicellulose, lignin, hydrated silica, and the ash content [2]. Te adsorbent, which is obtained from rice husk, can be a good alternative for the activated carbon applications [1–8]. Magnetic nanoparticles can also be used in adsorption process as adsorbent. Te features of the nanoparticles, whose sizes are less than 100 nm, are far more favorable than the fea- tures of the materials that have higher volumes. By the recent improvements in nanotechnology, the types of nanoparticles are synthesized successfully and gained attention to solve some of the environmental problems (acceleration of the coagulation of sludge, adsorption of radio nucleotides and organic dyes, and remediation of contaminated soil). Mag- netic nanoparticles have large surface areas, highly magnetic characteristics, and high removal efciencies. In addition, they have an advantage as the speedy and easy removal of the adsorbent from the solution (by the help of magnetic feld). Also, compounds can be removed from the magnetic particles and can be reused [9–11]. Tere are some studies (AC/TiO 2 , GAC/ZrO 2 , TiO 2 /sepiolite, and chitosan/ZnO) which prove that nanotechnological applications improved Hindawi Publishing Corporation Journal of Nanomaterials Volume 2016, Article ID 6304096, 10 pages http://dx.doi.org/10.1155/2016/6304096