Chemically modified magnetic chitosan microspheres for Cr(VI) removal from acidic aqueous solution--颗粒学报PARTICUOLOGY

Sun, X., Li, Q., Yang, L., & Liu, H. (2016). Chemically modified magnetic chitosan microspheres for Cr(VI) removal from acidic aqueous solution. Particuology, 26, 79-86. https://doi.org/10.1016/j.partic.2015.11.003

Chemically modified magnetic chitosan microspheres for Cr(VI) removal from acidic aqueous solution

Xitong Sun ^{a 1}, Qian Li ^{b 1}, Liangrong Yang ^c, Huizhou Liu ^{a c *}

a CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
b School of Biological Engineering, Dalian Polytechnic University, Dalian 116034, China
c CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China

10.1016/j.partic.2015.11.003

Volume 26, June 2016, Pages 79-86

Received 19 September 2015, Revised 17 November 2015, Accepted 30 November 2015, Available online 24 February 2016, Version of Record 18 April 2016.

E-mail: sunxt@qibebt.ac.cn; hzliu@ipe.ac.cn

Highlights

• Chemically modified magnetic chitosan microspheres were prepared and used for Cr(VI) removal.

• Its maximum adsorption capacity was 233.1 mg/g at pH 2.5 and 25 °C.

• The adsorbent exhibited strong acid resistance and a magnetic responsive nature.

• The adsorbent with 95.6% desorption efficiency had a good reusability.

Abstract

A bioadsorbent composed of magnetic silica nanoparticles encapsulated by chitosan microspheres was prepared by the emulsion cross-linking method, and it was then modified with quaternary ammonium groups by reaction with ethylenediamine and glycidyl trimethylammonium chloride. Characterization of the bioadsorbent indicated that it was highly acid resistant and magnetically responsive. The bioadsorbent was then used to remove Cr(VI) from acidic aqueous solution. The results of batch experiments indicated that the optimal pH value was 2.5, and the adsorbent exhibited low pH dependence. The maximum adsorption capacity was 233.1 mg/g at pH 2.5 and 25 °C, and the equilibrium time was determined to be 40–120 min depending on the initial Cr(VI) concentration. The adsorbent could be effectively regenerated using a mixture of 0.3 mol/L NaOH and 0.3 mol/L NaCl with a desorption efficiency of 95.6%, indicating high reusability. In conclusion, the bioadsorbent shows potential for Cr(VI) removal from acidic wastewater.

Graphical abstract

Keywords

Chitosan; Quaternary ammonium; Magnetic; Adsorption; Cr(VI)

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