Research
Title: | Almond Shell-Derived, Biochar-Supported, Nano-Zero-Valent Iron Composite for Aqueous Hexavalent Chromium Removal: Performance and Mechanisms |
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First author: | Shu, Yaorong; Ji, Bin; Cui, Baihui; Shi, Yuting; Wang, Jian; Hu, Mian; Luo, Siyi; Guo, Dabin |
Journal: | NANOMATERIALS |
Years: | 2020 |
DOI: | 10.3390/nano10020198 |
Abstract: | Nano-zero-valent iron biochar derived from almond shell (nZVI-ASBC) was used for hexavalent chromium (CR) removal. Experiments showed that pH was the main factor (p < 0.01) that affected the experimental results. At a dosage of 10 mg.L-1 and pH of 2-6, in the first 60 min, nZVI-ASBC exhibited a removal efficiency of 99.8%, which was approximately 20% higher than the removal yield at pH 7-11. Fourier transform infrared spectroscopy results indicated N-H was the main functional group that influenced the chemisorption process. The pseudo second-order dynamics and Langmuir isotherm models proved to be the most suitable. Thermodynamic studies showed that the reaction was exothermic and spontaneous at low temperatures (T < 317 K). Various interaction mechanisms, including adsorption and reduction, were adopted for the removal of Cr(VI) using the nZVI-ASBC composite. The findings showed that the BC-modified nZVI prepared with almond shell exerts a good effect and could be used for the removal of Cr(VI). |