TY - JOUR ID - 3266 TI - Sulfate Removal from Water Using Activated Red Mud: Kinetic, Isotherm and Thermodynamic Studies JO - Amirkabir Journal of Civil Engineering JA - CEEJ LA - en SN - 2588-297X AU - Dolat Abad, Alireza Arhami AU - Ganjidoust, Hossein AD - Tarbiat Modares University, Civil and Environmental Engineering Faculty, Tehran, Iran AD - Y1 - 2021 PY - 2021 VL - 53 IS - 2 SP - 439 EP - 456 KW - Adsorption KW - Red mud KW - Activated red mud KW - Sulfate KW - Thermodynamics DO - 10.22060/ceej.2019.15356.5894 N2 - In this study, the absorption of sulfates on activated aluminum industry waste (red mud) has been investigated in a batch system by the OFAT method. The properties of the absorbent were analyzed using a scanning electron microscope (SEM), BET surface area, X-ray diffraction (XRD), XRF. The process of sulfate absorption was done in a volume of 200 mL and a mixer speed of 150 rpm. The optimum absorption conditions were derived in an equilibrium time of 90 minutes, initial concentration of 100 ppm, pH=4, the temperature of 65 ◦C, and 7.5 g/L doses of the absorbent. The efficiency of sulfate removal was 73.1 percent at the optimum conditions. Thermodynamic analysis of absorption showed that the absorption process at all analyzed temperatures had occurred spontaneously. Sulfate absorption kinetics on composite surfaces followed a pseudo second-order equation and absorption isotherm had high conformity with Langmuir isotherm (r=0.994) and the maximum absorption capacity of it according to Langmuir isotherm is 13.07 mg of sulfate per gram of the absorbent. UR - https://ceej.aut.ac.ir/article_3266.html L1 - https://ceej.aut.ac.ir/article_3266_a25ea1c3c79593fc1a1ea51e562cf111.pdf ER -