title: The adsorption and mass-transfer process of cationic red X-GRL dye on natural zeolite.
abstract: The adsorption behavior of natural zeolite was studied in order to determine the adsorption capacity and mass-transfer process of cationic red X-GRL (C(18)H(21)BrN(6)) onto the adsorbent. The adsorption tests to determine both the uptake capacity and the mass-transfer process at equilibrium were performed under batch conditions, which showed rapid uptake in general for the initial 5 min, corresponding to 92% total removal. The equilibrium adsorption capacity value (q(e,cal)) in pseudo-second-order kinetics was 13.51 mg/g at 293 K and the whole adsorption process was governed by physical adsorption with an endothermic, endothermic spontaneous nature. Adsorption tests indicated that the zeolite has great potential as an alternative low-cost material in the treatment of X-GRL drainage. However, the mass-transfer process to determine the rate-controlling steps showed that both film diffusion and pore diffusion were important in controlling the adsorption rate. The adsorption process was governed by film diffusion while pore diffusion was poor because the X-GRL molecules could not penetrate into the zeolite easily. The X-GRL molecules were only adsorbed on the external surface of the zeolite. Hence, to improve the adsorption capacity of natural zeolite further, modification to expand its micropores is necessary.
authors.affiliation: School of Resources and Environment Engineering, Wuhan University of Technology, No. 122 Luoshi Road, Hongshan, Wuhan 430070, China E-mail: 1289231430@qq.com.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Tian
authors.affiliation: School of Resources and Environment Engineering, Wuhan University of Technology, No. 122 Luoshi Road, Hongshan, Wuhan 430070, China E-mail: 1289231430@qq.com.
authors.forename: Junfang
authors.initials: J
authors.lastname: Guan
authors.affiliation: School of Resources and Environment Engineering, Wuhan University of Technology, No. 122 Luoshi Road, Hongshan, Wuhan 430070, China E-mail: 1289231430@qq.com.
authors.forename: Huimin
authors.initials: H
authors.lastname: Gao
authors.affiliation: Wuhu Conch Profiles and Science Co., Ltd, Wuhu Anhui 241009, China.
authors.forename: Yafei
authors.initials: Y
authors.lastname: Wen
authors.affiliation: School of Resources and Environment Engineering, Wuhan University of Technology, No. 122 Luoshi Road, Hongshan, Wuhan 430070, China E-mail: 1289231430@qq.com.
authors.forename: Zijie
authors.initials: Z
authors.lastname: Ren
mesh_terms: D000327:Adsorption; D001391:Azo Compounds; D002412:Cations; D004396:Coloring Agents / Q000737:chemistry; D004058:Diffusion; D007700:Kinetics; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods; D017641:Zeolites
chemical_list: D001391:Azo Compounds; D002412:Cations; D004396:Coloring Agents; C516485:Red X-GRL; D014874:Water Pollutants, Chemical; D017641:Zeolites