Cr(VI) removal from aqueous solution using biochar modified with Mg/Al-layered double hydroxide intercalated with ethylenediaminetetraacetic acid

• Published in: Bioresource technology Vol. 276; pp. 127 - 132
• Main Authors: Huang, Danlian, Liu, Caihong, Zhang, Chen, Deng, Rui, Wang, Rongzhong, Xue, Wenjing, Luo, Hao, Zeng, Guangming, Zhang, Qing, Guo, Xueying
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2019
• Subjects: Adsorption; aqueous solutions; bamboos; Biochar; biomass; chromium; Cr(VI); EDTA (chelating agent); electrostatic interactions; Fourier transform infrared spectroscopy; heavy metals; hydroxides; Layered double hydroxides; wastewater; X-ray diffraction; Cr(VI); Adsorption; Biochar; Layered double hydroxides
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2018.12.114

•Biochar loaded with nanoparticles was prepared for Cr(VI) adsorption.•EDTA intercalated LDH significantly improved sorption capacity of Cr(VI).•Adsorption process obeys chemisorption and monolayer adsorption. In this study, the bamboo biomass loaded with ethylenediaminetetraacetic acid (EDTA) intercalated Mg/Al-layered double hydroxides (LDH) was calcined to obtain a novel nano-adsorbent (BC@EDTA-LDH), and BC@EDTA-LDH was used to remove hexavalent chromium (Cr(VI)) in aqueous solutions. The results showed that the interaction between LDH and Cr(VI) on biochar played a dominant part in adsorption. The LDH of Cr(VI) intercalation was successfully reconstructed after adsorption. Fourier transform infrared spectra and X-ray diffraction results confirmed the reconstruction of Mg/Al-LDH. LDH had sustained release effect on the solution. As the pH values increased, the electrostatic repulsion between Cr2O72− and OH– increased, and there existed competition for adsorption sites. The maximum adsorption capacity of Cr(VI) was 38 mg/g. The data was well-fitted with pseudo second-order model and Langmuir-Freundlich model. BC@EDTA-LDH showed a high adsorption capacity and was potentially suitable for removing heavy metals in wastewater.