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Potassium permanganate modification of hydrochar enhances sorption of Pb(II), Cu(II), and Cd(II)
Citation:
Zhang, Y., Y. Wan, Y. Zheng, Y. Yang, J. Huang, H. Chen, AND B. Gao. Potassium permanganate modification of hydrochar enhances sorption of Pb(II), Cu(II), and Cd(II). Bioresource Technology. Elsevier Online, New York, NY, 386:129482, (2023). https://doi.org/10.1016/j.biortech.2023.129482
Impact/Purpose:
Heavy metal pollution remains one of the most pressing global issues affecting human health and the environment. This study examined wheat straw hydrochar modified with 0.2 M KMnO4 as an adsorbent for remediation of Pb(II), Cd(II) and Cu(II). The KMnO4 modified hydrochar had a specific surface area eight times higher than the pristine hydrochar with increased oxygen-containing functional groups (e.g., hydroxyl and carboxyl) and MnOx on the surface. The heavy metal adsorption capacity was greatly improved compared with the pristine hydrochar and some other adsorbents. The modified hydrochar can be used as a low-cost adsorbent for practical applications.
Description:
Hydrochars formed by hydrothermal carbonization of hickory wood, bamboo, and wheat straw at 200 °C were modified by potassium permanganate (KMnO4) for the sorption of Pb(II), Cd(II), and Cu(II). The wheat straw hydrochar (WSHyC) modified with 0.2 M KMnO4 resulted in the most promising adsorbent (WSHyC-0.2KMnO4). Characterization of WSHyC and WSHyC-0.2KMnO4 revealed that the modified hydrochar features large specific surface area, rich of surface oxygenic functional groups (OCFG), and a significant amount of MnOx micro-particles. Batch adsorption experiments indicated that the adsorption rate by WSHyC-0.2KMnO4 was faster than for WSHyC, attaining equilibrium after around 5 h. The optimum adsorption capacity (Langmuir) of Pb(II), Cd(II), and Cu(II) by WSHyC-0.2KMnO4 was 189.24, 29.06 and 32.68 mg/g, respectively, 12 ∼ 17 times greater than by WSHyC. The significantly enhanced heavy metal adsorption can be attributable to the increased OCFG and MnOx microparticles on the surface, thereby promoting ion exchange, electrostatic interactions, and complexation mechanisms.
URLs/Downloads:
DOI: Potassium permanganate modification of hydrochar enhances sorption of Pb(II), Cu(II), and Cd(II)
https://pubmed.ncbi.nlm.nih.gov/37451511/