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Indexed by:期刊论文

Date of Publication:2018-01-15

Journal:JOURNAL OF ENVIRONMENTAL MANAGEMENT

Included Journals:PubMed、SCIE

Volume:206

Page Number:989-998

ISSN No.:0301-4797

Key Words:Eucalyptus sawdust; Hydrothermal carbonization; Hexavalent chromium; Low concentration potassium hydroxide; Adsorption

Abstract:In this study, Eucalyptus sawdust was hydrothermally carbonized, and the resulting biochar was modified by a low concentration potassium hydroxide. The morphology and surface property was characterized by SEM-EDS, BET, FFIR and XPS techniques. A series of batch adsorption experiments were conducted to screen out the optimum conditions, and to investigate the isotherm, kinetics and thermodynamic behaviors. The results indicated that a high adsorption capacity of hexavalent chromium (q(e) 45.88 mg/g) was achieved by the combining of hydrothermal carbonization at 220 degrees C and 0.05 N potassium hydroxide modification, and a high biochar yield (47.61%) was obtained. The isotherm, kinetics and thermodynamic studies suggested that the spontaneously and endothermically chemical adsorption was the main mechanism, which was partially supported by BET, FTIR and XPS results. This finding suggested that the combination of hydrothermal carbonization and a subsequent low alkali modification was an effective method to prepare a high-performance adsorbent for hexavalent chromium removal. (C) 2017 Elsevier Ltd. All rights reserved.