Effects of metal ions and pH on ofloxacin sorption to cassava residue-derived biochar

Peng Huang; Chengjun Ge; Dan Feng; Huamei Yu; Jiwei Luo; Jiatong Li; P J Strong; Ajit K Sarmah; Nanthi S Bolan; Hailong Wang

doi:10.1016/j.scitotenv.2017.10.177

Effects of metal ions and pH on ofloxacin sorption to cassava residue-derived biochar

Sci Total Environ. 2018 Mar:616-617:1384-1391. doi: 10.1016/j.scitotenv.2017.10.177. Epub 2017 Oct 23.

Authors

Peng Huang¹, Chengjun Ge², Dan Feng¹, Huamei Yu¹, Jiwei Luo¹, Jiatong Li¹, P J Strong³, Ajit K Sarmah⁴, Nanthi S Bolan⁵, Hailong Wang⁶

Affiliations

¹ College of Resources and Environment, Institute of Tropical Agriculture and Forestry, Hainan University, Renmin Road, Haikou 570228, China.
² College of Resources and Environment, Institute of Tropical Agriculture and Forestry, Hainan University, Renmin Road, Haikou 570228, China; College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China. Electronic address: 990963@hainu.edu.cn.
³ Queensland University of Technology, GPO Box 2432, 2 George St, Brisbane, QLD 4001, Australia.
⁴ Civil & Environmental Engineering Department, Faculty of Engineering, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
⁵ Global Centre for Environmental Remediation (GCER), Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia.
⁶ School of Environment and Chemical Engineering, Foshan University, Foshan, Guangdong 528000, China; Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang A & F University, Lin'an, Hangzhou 311300, China; Guangdong Dazhong Agriculture Science Co. Ltd., Dongguan, Guangdong 523169, China. Electronic address: hailong.wang@fosu.edu.cn.

PMID: 29074248
DOI: 10.1016/j.scitotenv.2017.10.177

Abstract

In this study, the impacts of various cations, cation strength and pH on ofloxacin (OFL) adsorption to cassava residue-derived biochars were determined. The associated adsorption mechanisms are discussed. The biochars were prepared at pyrolysis temperatures ranging from 350°C to 750°C, and labeled as CW350, CW450, CW550, CW650 and CW750. The Freundlich model provided the best fit to describe the adsorption capacity of OFL and the Freundlich coefficient (logK_f) increased with increasing pyrolysis temperature. The inclusion of Zn²⁺ or Al³⁺ increased OFL sorption capacities of five biochars, while Cu²⁺ reduced sorption to CW450 and CW550. No significant impacts on OFL sorption were observed in the presence of K⁺ and Ca²⁺. The concentration of Ca²⁺ affected the adsorption capacity of CW550, but had no significant impact on other biochars. The pH of OFL solution, ranging from 3 to 9, had no significant changes on OFL adsorption by all the tested biochars. Results of FTIR spectra and zeta potential indicated that electrostatic interactions, cationic exchange, metal bridging and micropore filling could be the main sorption mechanism between OFL and biochars. These studies indicated that cassava residue can be converted into biochars that are effective adsorbents for removing OFL from aqueous solution.

Keywords: Adsorption; Antibiotics; Cation species; Ion strength; Pyrolysis temperature.