Adsorptive removal of anionic azo dye by Al3+-modified magnetic biochar obtained from low pyrolysis temperatures of chitosan
writer：Ru Jiang, Hua-Yue Zhu, Yong-Qian Fu, Xin Li, Sheng-Tao Jiang, Jian-Bing Li
keywords：chitosan, adsorption
source：期刊
Issue time：2023年
Magnetic γ-Fe2O3/Al3+@chitosan-derived biochar (m-Fe2O3/Al3+@CB) was prepared by introducing magnetic maghemite (γ-Fe2O3) nanoparticles and aluminium sulfate [Al2(SO4)3] into chitosan-derived biochar (CB) obtained at low pyrolysis temperatures. m-Fe2O3/Al3+@CB
was used to remove typical anionic azo dye (congo red, CR). Effects of initial CR concentration,
contact time, initial pH value, background electrolytes and temperature on CR adsorption by m-Fe2O3/Al3+@CB were studied. Compared with magnetic chitosan-derived biochar (m-Fe2O3@CB), m-Fe2O3/Al3+@CB exhibited excellent performance for a wider range of pH values (pH 1-7) and in the presence of background electrolyte. The introduction of Al3+ is an effective method for improving the properties of magnetic chitosan-derived biochar. High CR adsorption capacity (636.94 mg g-1) of m-Fe2O3/Al3+@CB could result from collaborative effect of flocculation/coagulation and electrostatic attraction. These results demonstrated that m-Fe2O3/Al3+@CB
is a potential adsorbent for effective removal of organic dyes from
aqueous solution due to its
high adsorption capacity and convenient magnetic recovery,
and stronger anti-interference ability against coexisting anions in wastewater.