New insights into co-adsorption of Cr6+ and chlortetracycline by a new fruit peel based biochar composite from water: Behavior and mechanism

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2023-09, Vol.672, p.131764, Article 131764
• Main Authors: Liang, Jing-Yi, Zhang, Wen-Xuan, Yao, Xiao-Wen, Chen, Man-Li, Chen, Xie, Kong, Ling-Jun, Diao, Zeng-Hui
• Format: Article
• Language: English
• Subjects: Antibiotics; Biochar; Chlortetracycline (CTC); Cr6; Heavy metals
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2023.131764

Nowadays, the residual heavy metals and antibiotics in water and soil have a potential threat to human being health, thereby their purification is of great importance. In this study, the application of Cr6+ and chlortetracycline (CTC) removal using a new fruit peel based biochar composite (FPBC) had been explored. Batch experiments results showed that FPBC presented excellent removal performance on Cr6+ and CTC, and the simultaneous removal efficiencies of Cr6+ and CTC were 97% and 81% within 180 min, respectively. The adsorption kinetics and isotherms of Cr6+ by FPBC could be well described by the pseudo-second-order and Langmuir models, respectively, and its adsorption was a spontaneous endothermic process. The inhibitory of the coexisting anions on Cr6+ removal of followed the order of HPO43-> HCO3-> SO42->NO3-> Cl-. The simultaneous removal of Cr6+ and CTC by FPBC had been achieved at low CTC content levels. The presence of NaCl showed a significant inhibitory on Cr6+ removal but a positive effect on CTC removal at low content level. A potential reaction mechanism of both Cr6+ and CTC removal over FPBC was proposed on the basic of the comprehensive characterizations and adsorption performance. Both reduction and surface precipitation reactions might be dominant in Cr6+ removal process, whereas both complexation and hydrogen bond interaction might be mainly responsible for CTC removal. These findings suggested that this fruit peel based biochar composite might be a promising material for the remediation of Cr6+ and CTC-contaminated wastewater. [Display omitted] •A new fruit peel based biochar composite (FPBC) was firstly synthesized.•Cr6+ adsorption was well described by pseudo-second-order and Langmuir models.•NaCl showed an inhibitory on Cr6+ removal but a positive effect on CTC removal.•FPBC presented a high simultaneous removal of Cr6+ and CTC.•A potential mechanism for Cr6+ and CTC removal over FPBC was proposed.