<p> SUPPORTING INFORMATION</p><p>Green Preparation of a Novel Red Mud@Carbon Composite and </p><p>Its Application for Adsorption of 2,4-Dichlorophenoxyacetic Acid</p><p> from Aqueous Solution</p><p>Omer Kazaka, Yasin Ramazan Ekerb, Ilker Akinc, Haluk Bingold, Ali Tora,</p><p> aDepartment of Environmental Engineering, Necmettin Erbakan University, 42090, Konya, Turkey bDepartment of Metallurgical and Materials Engineering, Necmettin Erbakan University, 42090, Konya, Turkey cDepartment of Chemistry, Selcuk University, 42075, Konya, Turkey dDepartment of Chemistry, A.K. Education Faculty, Necmettin Erbakan University, Konya, 42090, Turkey</p><p> Corresponding author. e-mail: [email protected], Tel: + 90 332 3237926-4018, Fax: + 90 332 3238225. 1 Figure S1. XRD patterns of red mud, carbon spheres and red mud@C composite. (a:</p><p> boehmite (AlOOH), b: goethite (FeOOH), c: hematite (Fe2O3), d: rutile (TiO2),</p><p> e: quartz (SiO2).</p><p>2 Figure S2. Removal efficiency of red mud, carbon spheres and red mud@C composite. (pH</p><p> of solution: 3.0, amount of red mud@C composite: 1 g/L, contact time: 2 h,</p><p> shaking speed: 150 rpm, temperature: 251 oC).</p><p>3 Figure S3. Linear plot of pseudo first-order kinetic model (Concentrations of 2,4-D: 20 and 100 mg/L, initial pH: 3.0, amount of red mud@C composite: 1 g/L, shaking speed: 150 rpm, temperature: 251 oC).</p><p>Figure S4. Linear plot of pseudo second-order kinetic model (Concentrations of 2,4-D: 20 and 100 mg/L, initial pH: 3.0, amount of red mud@C composite: 1 g/L, shaking speed: 150 rpm, temperature: 251 oC).</p><p>4 Figure S5. Plot of intra-particle diffusion model (Concentrations of 2,4-D: 20 and 100 mg/L,</p><p> initial pH: 3.0, amount of red mud@C composite: 1 g/L, shaking speed: 150 rpm,</p><p> temperature: 251 oC).</p><p>5 Figure S6. Linear plots of Langmuir, Freundlich and Redlich-Peterson isotherm models for </p><p> the adsorption of 2,4-D from aqueous solution (initial pH: 3.0, contact time: 1 h, </p><p> amount of red mud@C composite: 1 g/L, shaking speed: 150 rpm, temperature: </p><p>251 oC).</p><p>6 Figure S7. Changes in adsorption capacity of regenerated red mud@C composite with</p><p> adsorption/desorption cycles.</p><p>7</p>