Enhanced adsorption of tetracycline by an iron and manganese oxides loaded biochar: Kinetics, mechanism and column adsorption

• Published in: Bioresource technology Vol. 320; no. Pt A; p. 124264
• Main Authors: Zhang, Xin, Li, Yaru, Wu, Mengru, Pang, Yao, Hao, Zhenbing, Hu, Mian, Qiu, Rongliang, Chen, Zhihua
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2021
• Subjects: Adsorption; Biochar; Charcoal; Iron; Kinetics; Manganese; Manganese Compounds; Mechanism; Oxides; sorption isotherms; technology; Tetracycline; wastewater; Water Pollutants, Chemical - analysis; Adsorption; Biochar; Mechanism; Tetracycline
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2020.124264

[Display omitted] •Fe/Mn oxides loaded biochar could enhance the adsorption of tetracycline.•γ-Fe2O3 and MnO2 were the main crystalline phases of Fe/Mn oxides.•Fe/Mn oxides play complex acid and base roles to enhance the tetracycline adsorption.•Adsorption of tetracycline follow Elovich kinetic model and Langmuir isotherm. A Fe/Mn oxides loaded biochar (FeMn-BC) was prepared to enhance the adsorption of tetracycline (TC). γ-Fe2O3 and MnO2 were assigned to the Fe and Mn oxides, respectively. The enhanced adsorption of TC was dominated by the loaded γ-Fe2O3 and MnO2. According to Akaike-Information-Criteria evaluation, Elovich kinetic and Langmuir isotherm models could best describe the adsorption with a maximum capacity of 14.24 mg/g. During adsorption process, the γ-Fe2O3 and MnO2 hydrolyzed into hydroxides (FeOOH and MnOOH) which acted as bases to complex with TC2− ion under alkaline condition (pH = 11). After the adsorption, the concentrations of leached Fe and Mn could meet the requirements PRC standards GB13456-2012 and GB8978-1996, respectively. The FeMn-BC had ~24% on TC removal (initial concentration of 20 mg/L) after four-cycles regeneration. The FeMn-BC was also available for TC adsorptions in column tests and actual wastewater.