Removal of hexavalent chromium using activated and magnetic Ziziphus Jujube seed biochar - a column study

• Published in: Separation science and technology Vol. 59; no. 16; pp. 1550 - 1570
• Main Authors: Manthira Giri, Prathap, Parthasarathy, Purushothaman
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 01.11.2024; Taylor & Francis Ltd
• Subjects: Adsorption; Bed height; Charcoal; Chromium; chromium: flow rate; fixed bed column; Fixed beds; Flow rates; Flow velocity; Functional groups; Hexavalent chromium; magnetic biochar; Magnetic properties; Physical characteristics; Ziziphus
• ISSN: 0149-6395; 1520-5754
• DOI: 10.1080/01496395.2024.2394476

In this study, activated and magnetic biochar prepared from Ziziphus Jujube Seeds (ZJS) is used to remove Hexavalent Chromium (Cr(VI)) using Fixed Bed Column Experiment. Physicochemical characteristics of the activated and magnetic biochar such as functional groups, surface area, morphological study, and magnetic properties were analyzed. The column experiment was carried out for varying bed heights (2, 4, 6, 8, 10 cm), flow rates (20, 30 ml/min), and initial chromium concentrations (40, 60, 80 ppm) to determine adsorption performance of the studied biochar. The characteristic study found that magnetic biochar (MB) has good magnetic properties and crystallinity nature with essential functional groups such as C-O, FeO. The study found that Magnetic Biochar (MB) effectively removed 99% of hexavalent chromium through column adsorption under optimal conditions, including bed height of 6 cm, 60ppm Chromium concentration, and flow rate of 20 ml/min. Kinetic model study showed that Magnetic Biochar (MB) showed very good agreement with Adam Bohart Model, with R 2 of 0.97, which is best fit model than other model studies whereas the other model showed a lesser R 2 value. The study reveals that magnetic biochar from Ziziphus Jujube Seed is optimal adsorbent for removal of Cr(VI) through column adsorption experiment. Activated, Magnetic biochar and Magnetic activated biochar was used to remove Cr(VI) in fixed bed column studies. Maximum Cr(VI) removal efficiency was achieved at 6 cm bed height and 20 ml/min for all biochars. Magnetic biochar showed maximum Cr(VI) removal efficiency of 99% at 60 ppm and 95% at 40 and 80 ppm. Langmuir isotherm, Pseudo second order kinetic and Adam Bohart Model were the best fit kinetic model.