Adsorption of nitrate in water by CTAB-modified MgFe layered double hydroxide composite biochar at low temperature: Adsorption characteristics and mechanisms. Issue 1 (February 2023)

• Record Type: Journal Article
• Authors: Wang, Weixin; Zhu, Qi; Huang, Ruiyao; Hu, Yuhan
• Is Part Of: Journal of environmental chemical engineering. Volume 11:Issue 1(2023)
• Publication Date: 2023-02
• Subjects: Layered double hydroxide -- Biochar -- Low temperature -- Adsorption -- Nitrate; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.109090
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: In this study, for the purpose of improving the removal effect of biochar on nitrate in wastewater at lower temperature, MgFe layered double hydroxides (MgFe-LDHs) were precipitated on the surface and in the pores of corn stover biochar (BC) in the presence of surfactant cetyltrimethylammonium bromide (CTAB) to prepare a novel adsorbent MgFe-CTAB-LDHs/BC. The result shows that BC has abundant pore structure and MgFe-LDHs has been uniformly loaded on the surface of BC and in the pores, which greatly reduced the agglomeration of LDHs. Part of CTAB was on the surface of BC, making it more positively charged, and the other part entered the interlayer of LDHs, changing the interlayer spacing, which is beneficial to adsorption. Meanwhile, the hydroxyl groups and metal hydroxides in LDHs and numerous active groups of BC enhanced the adsorption capacity through synergistic effect. The successful preparation of MgFe-CTAB-LDHs/BC was proved by various characterization analyses and the adsorption mechanism of nitrate on MgFe-CTAB-LDHs/BC was investigated through experimental demonstration and characterization analysis. The adsorption kinetics and isotherm studies also showed that the adsorption rate of MgFe-CTAB-LDHs/BC for nitrate was improved, and it still had a good adsorption effect at lower temperature. This study aims to provide a novel environmentally friendly adsorbent for nitrate adsorption at lower temperature. Graphical Abstract: ga1 Highlights: Modified MgFe-LDHs composite biochar was successfully synthesized. The maximum adsorption capacity was 65.13 mg/g for nitrate. The material could be effectively used for the adsorption of nitrate in water. The material maintained a good ability to adsorb nitrate at low temperature. There were both physical adsorption and chemical adsorption in the process.