title: The optimization of As(V) removal over mesoporous alumina by using response surface methodology and adsorption mechanism.
abstract: The Box-Behnken Design of the response surface methodology was employed to optimize four most important adsorption parameters (initial arsenic concentration, pH, adsorption temperature and time) and to investigate the interactive effects of these variables on arsenic(V) adsorption capacity of mesoporous alumina (MA). According to analysis of variance (ANOVA) and response surface analyses, the experiment data were excellent fitted to the quadratic model, and the interactive influence of initial concentration and pH on As(V) adsorption capacity was highly significant. The predicted maximum adsorption capacity was about 39.06 mg/g, and the corresponding optimal parameters of adsorption process were listed as below: time 720 min, temperature 52.8 °C, initial pH 3.9 and initial concentration 130 mg/L. Based on the results of arsenate species definition, FT-IR and pH change, As(V) adsorption mechanisms were proposed as follows: (1) at pH 2.0, H₃AsO₄ and H₂AsO₄(-) were adsorbed via hydrogen bond and electrostatic interaction, respectively; (2) at pH 6.6, arsenic species (H₂AsO₄(-) and HAsO₄(2-)) were removed via adsorption and ion exchange, (3) at pH 10.0, HAsO₄(2-) was adsorbed by MA via ion exchange together with adsorption, while AsO₄(3-) was removed by ion exchange.
authors: Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, PR China.
authors: Caiyun
authors: C
authors: Han
authors: Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, PR China.
authors: Hongping
authors: H
authors: Pu
authors: Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, PR China.
authors: Hongying
authors: H
authors: Li
authors: Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, PR China.
authors: Lian
authors: L
authors: Deng
authors: Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, PR China.
authors: Si
authors: S
authors: Huang
authors: Research Center for Analysis and Measurement, Kunming University of Science and Technology, Kunming 650093, PR China.
authors: Sufang
authors: S
authors: He
authors: Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, PR China. Electronic address: environcatalysis222@yahoo.com.
authors: Yongming
authors: Y
authors: Luo
mesh_terms: D000327:Adsorption; D000537:Aluminum Oxide / Q000737:chemistry*; D001151:Arsenic / Q000737:chemistry*; D012044:Regression Analysis; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D014874:Water Pollutants, Chemical; D000537:Aluminum Oxide; D001151:Arsenic