EDTA for Adsorptive Removal of Sulfamethoxazole

Desalination and Water Treatment 207 (2020) 321–331 www.deswater.com December

doi: 10.5004/dwt.2020.26391

Magnetic porous Fe–C materials prepared by one-step pyrolyzation of NaFe(III)EDTA for adsorptive removal of sulfamethoxazole

Jiandong Zhua,†, Liang Wanga,†, Yawei Shia,*, Bofeng Zhangb, Yajie Tianc, Zhaohui Zhanga, Bin Zhaoa, Guozhu Liub,*, Hongwei Zhanga,d aState Key Laboratory of Separation Membranes and Membrane Processes, School of Environmental Science and Engineering, Tiangong University, Tianjin 300387, China, Tel./Fax: +86 22 83955392; emails: [email protected] (Y.W. Shi), [email protected] (J.D. Zhu), [email protected] (L. Wang), [email protected] (Z.H. Zhang), [email protected] (B. Zhao), [email protected] (H.W. Zhang) bSchool of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China, Tel. +86 22 27892340; emails: [email protected] (G.Z. Liu), [email protected] (B.F. Zhang) cHenan Engineering Research Center of Resource & Energy Recovery from Waste, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, China, email: [email protected] (Y.J. Tian) dSchool of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China

Received 25 February 2020; Accepted 25 July 2020

abstract A series of magnetic porous Fe–C materials were prepared by one-step pyrolyzation of ethylene- diaminetetraacetic acid sodium iron(III) at 500°C–800°C and then employed as adsorbents for sulfamethoxazole (SMX) adsorption. The one prepared at 700°C (Fe–C-700) was selected as the opti- mum one with an adsorption amount of 82.3 mg g–1 at pH 5.0 and 30°C. This was mainly ascribed to its higher surface area which offered more space for hydrophobic and electron donor–acceptor interactions between SMX and its surface. The adsorption kinetics was analyzed with three models. –1 With the increase of concentration, the k1 value decreased from 0.383 to 0.329 min , and the k2 value decreased from 0.0292 to 0.0101 g mg–1 min–1. The thermodynamic analysis showed that SMX adsorption on Fe–C-700 was a spontaneous exothermic entropy-decreasing process. The effects of adsorbent dosage, pH, metal ions and humic acid on SMX adsorption were also investigated. The spent Fe–C-700 could be easily separated and recycled after adsorption due to its magnetic feature. Keywords: Adsorption; Sulfamethoxazole; Magnetic carbon; Pyrolyzation

* Corresponding authors. † These authors contributed equally.