Luo X, Du H, Zhang X, Yang Y. Amine-functionalized magnetic biochars derived from invasive plants Alternanthera philoxeroides for enhanced efficient removal of Cr(VI): performance, kinetics and mechanism studies.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022;
29:78092-78106. [PMID:
35689769 DOI:
10.1007/s11356-022-20987-4]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
In this study, novel magnetic biochars derived from Alternanthera philoxeroides and modified by different amines (hexanediamine, melamine, and L-glutathione) were successfully prepared by hydrothermal carbonization and employed as an efficient adsorbent for Cr(VI). When pH = 2.0, T = 25 °C, c0 = 100 mg/L, and the dosage of biochars is 0.05 g, the maximum adsorption capacity of Cr(VI) by pristine biochar (BAP) was 42.47 mg/g and modified biochars (MFBAP, MEBAP, LBAP) was 80.58, 62.26, and 55.66 mg/g, respectively. It was found that hexanediamine and melamine could enhance the SBET of biochars, while L-glutathione could reduce its SBET, which could be supported by BET measurement and SEM images. Adsorption kinetics and isotherm studies showed that the Cr(VI) adsorption process of MFBAP followed Elovich kinetic model and Langmuir isotherm, respectively, which means that it was mainly a chemical adsorption process. The characterization results proved that -NH2 derived from amines plays a significant role in removing Cr(VI), which is mainly degraded by complexation reaction, electrostatic interaction, and reduction. In sum, the biochar modified by amines has excellent Cr(VI) adsorption performance, highly enhanced SBET, and excellent recyclability, which is a promising candidate for solving the problem of invasive plants and wastewater treatment.
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