Chin.J.Chem.Eng. ›› 2018, Vol. 26 ›› Issue (5): 1192-1199.doi: 10.1016/j.cjche.2017.11.008

• Energy, Resources and Environmental Technology • Previous Articles     Next Articles

Cr(Ⅲ) removal from simulated solution using hydrous magnesium oxide coated fly ash: Optimization by response surface methodology (RSM)

Min Xia1, Chunsong Ye1, Kewu Pi2, Defu Liu2, Andrea R. Gerson3   

  1. 1 School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, Hubei, China;
    2 School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan 430068, Hubei, China;
    3 Blue Minerals Consultancy, Wattle Grove, Tasmania 7109, Australia
  • Received:2017-09-25 Revised:2017-11-19 Online:2018-05-28 Published:2018-06-29
  • Contact: Min Xia,E-mail
  • Supported by:

    Supported by the State Key Development Program for Basic Research of China (2014CB460601) and the International S&T Cooperation Program of China (2014DFE70070).

Abstract: Hydrous magnesium oxide coated fly ash (MFA) has environmental remediation potential by providing a substrate for the adsorption of aqueous Cr(Ⅲ). Aqueous Cr(Ⅲ) adsorption onto MFA was examined as a function of MFA dosage, pH and initial Cr(Ⅲ) concentration with the Box-Behnken approach used for experimental design and optimization using response surface methodology (RSM). pH and dosage (dosage and concentration) have significant interactive effects on Cr(Ⅲ) adsorption efficiency. Analysis of variance shows that the response surface quadratic model is highly significant and can effectively predict the experimental outcomes. Cr(Ⅲ) removal efficiency of 98% was obtained using optimized conditions of MFA dosage, pH and initial Cr(Ⅲ) concentration of 1.57 g·L-1, 4.11 and 126 mg·L-1, respectively. Cr(Ⅲ) adsorption onto MFA is mainly attributed to the interaction between Cr(Ⅲ) and the functional group —OH of the hydrous magnesium oxide, in all probability caused by chemisorptions. The results of this study can conduce to reveal the interactions between Cr(Ⅲ) pollutant and MFA characteristics, posing important implications for the cost-effective alternative adsorption technology in the treatment of heavy metal containing wastewater.

Key words: Hydrous magnesium oxide, Fly ash, Cr (III) removal, Optimization, Response surface methodology (RSM)