title: Efficient removal of crystal violet using Fe3O4-coated biochar: the role of the Fe3O4 nanoparticles and modeling study their adsorption behavior.
abstract: Biochar shows great promise for use in adsorbing pollutants. However, a process for enhancing its adsorption capacity and re-collection efficiency is yet to be further developed. Hence, in this study, we developed a type of biochar coated with magnetic Fe3O4 nanoparticles (i.e., magnetic biochar (MBC)) and assessed its use for crystal violet (CV) adsorption as well as its recycling potential. The coating of Fe3O4 nanoparticles, which was not only on the surface, but also in the interior of biochar, performed two functions. Firstly, it produced a saturation magnetization of 61.48 emu/g, which enabled the biochar being efficiently re-collected using a magnet. Secondly, it significantly enhanced the adsorption capacity of the biochar (from 80.36 to 99.19 mg/g). The adsorption capacity of the MBC was determined to be the largest by so far (349.40 mg/g) for an initial CV concentration of 400 mg/L, pH of 6.0, and temperature of 40 °C, and the adsorption capacity of re-collected MBC was 73.31 mg/g. The adsorption of CV by the MBC was found to be a spontaneous and endothermic physical process in which the intraparticle diffusion was the limiting step. These findings inspire us to use other similar materials to tackle the menace of pollutions.
authors.affiliation: College of Life Sciences, Zhejiang University, 310058 Hangzhou, Zhejiang, PR China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Sun
authors.affiliation: College of Life Sciences, Zhejiang University, 310058 Hangzhou, Zhejiang, PR China.
authors.forename: Cai
authors.initials: C
authors.lastname: Hui
authors.affiliation: College of Life Sciences, Zhejiang University, 310058 Hangzhou, Zhejiang, PR China.
authors.forename: Rashid
authors.initials: R
authors.lastname: Azim Khan
authors.affiliation: School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, 311300 Lin'an, Zhejiang, PR China.
authors.forename: Jingting
authors.initials: J
authors.lastname: Du
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, 310058 Hangzhou, Zhejiang, PR China.
authors.forename: Qichun
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: College of Life Sciences, Zhejiang University, 310058 Hangzhou, Zhejiang, PR China.
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Zhao