Scholarlink

<p>A novel substitute for perfluorooctane sulfonate (PFOS), 6:2 Chlorinated polyfluoroalkyl ether acid (6:2 Cl-PFAES, F-53B), has been widely used in the electroplating and firefighting industries, raising concerns due to increasing environmental prevalence. This study systematically investigated the adsorption characteristics of F-53B by coconut shell activated carbon (CSAC) and elucidated the underlying mechanisms through adsorption kinetics, isotherm modeling, and multi-scale characterization. Results show that the maximum adsorption capacity of CSAC for F-53B reached 261.64&#xa0;mg/g, with the process best described by the pseudo-second-order kinetic model (R<sup>2</sup> &gt; 0.97) and the Langmuir isotherm (R<sup>2</sup> &gt; 0.94). Intraparticle diffusion modeling revealed a three-stage adsorption sequence: surface adsorption (0–2&#xa0;h), pore diffusion (2–8&#xa0;h), and dynamic equilibrium (8–48&#xa0;h). Solution pH influenced adsorption efficiency by regulating surface charge. Under acidic conditions (pH &lt; point of zero charge, pHzpc = 4.49), strong electrostatic interactions between protonated CSAC surfaces and anionic F-53B resulted in an 85% removal efficiency. In contrast, alkaline conditions (pH &gt; 7) led to a 70% reduction in adsorption efficiency (<i>p</i> &lt; 0.05) due to electric repulsion. The microporous-dominated structure of CSAC (specific surface area: 857.69&#xa0;m<sup>2</sup>/g; pore volume: 0.34&#xa0;cm<sup>3</sup>/g) facilitated synergistic adsorption mechanisms. Oxygen-containing functional groups (C-O, -OH) promoted hydrogen bonding and hydrophobic interactions, enhancing F-53B adsorption. Besides, CSAC is optimized for emergency scenarios, it achieves 99.9% removal efficiency for 1&#xa0;mg/L F-53B within 8&#xa0;h at room temperature, with a maximum capacity of 261.64&#xa0;mg/g; also, it maintains &gt; 85% removal efficiency under wide pH conditions and tolerates coexisting ions (e.g., Cl<sup>−</sup>, SO<sub>4</sub><sup>2−</sup>, Ca<sup>2+</sup>).This study highlights the multi-mechanistic synergy of CSAC in theremoval of F-53B, providing theoretical foundations and technical insights for biochar-based remediation of emerging contaminants.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Coconut shell activated carbon engineered for triphasic adsorption and multimechanistic removal of emerging contaminant F-53B

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年7月18日

查看全文
  • Yongming Wu,
  • Kexuan Pei,
  • Jiayu Zhou,
  • Jianzhong Xiong,
  • Yu Liu,
  • Panrong Li,
  • Fangfei Li,
  • Jiaqi Wang,
  • Xiangmin Liu,
  • Mi Deng,
  • Chenxi Wu

摘要

A novel substitute for perfluorooctane sulfonate (PFOS), 6:2 Chlorinated polyfluoroalkyl ether acid (6:2 Cl-PFAES, F-53B), has been widely used in the electroplating and firefighting industries, raising concerns due to increasing environmental prevalence. This study systematically investigated the adsorption characteristics of F-53B by coconut shell activated carbon (CSAC) and elucidated the underlying mechanisms through adsorption kinetics, isotherm modeling, and multi-scale characterization. Results show that the maximum adsorption capacity of CSAC for F-53B reached 261.64 mg/g, with the process best described by the pseudo-second-order kinetic model (R2 > 0.97) and the Langmuir isotherm (R2 > 0.94). Intraparticle diffusion modeling revealed a three-stage adsorption sequence: surface adsorption (0–2 h), pore diffusion (2–8 h), and dynamic equilibrium (8–48 h). Solution pH influenced adsorption efficiency by regulating surface charge. Under acidic conditions (pH < point of zero charge, pHzpc = 4.49), strong electrostatic interactions between protonated CSAC surfaces and anionic F-53B resulted in an 85% removal efficiency. In contrast, alkaline conditions (pH > 7) led to a 70% reduction in adsorption efficiency (p < 0.05) due to electric repulsion. The microporous-dominated structure of CSAC (specific surface area: 857.69 m2/g; pore volume: 0.34 cm3/g) facilitated synergistic adsorption mechanisms. Oxygen-containing functional groups (C-O, -OH) promoted hydrogen bonding and hydrophobic interactions, enhancing F-53B adsorption. Besides, CSAC is optimized for emergency scenarios, it achieves 99.9% removal efficiency for 1 mg/L F-53B within 8 h at room temperature, with a maximum capacity of 261.64 mg/g; also, it maintains > 85% removal efficiency under wide pH conditions and tolerates coexisting ions (e.g., Cl−, SO42−, Ca2+).This study highlights the multi-mechanistic synergy of CSAC in theremoval of F-53B, providing theoretical foundations and technical insights for biochar-based remediation of emerging contaminants.