Scholarlink

<p>This study focuses on developing a closed-loop system for waste management and pollutant removal, enhancing the sustainability and efficiency of treatment processes. Initially, the adsorption capacity of raw cypress nut powder (CN) for the removal of methylene blue (MB) from an aqueous medium is assessed. Once saturated with MB, the spent biosorbent underwent hydrothermal carbonization (HTC), followed by chemical activation using phosphoric acid. This process yielded an advanced material designated as CN/MB-AC. The transformation led to a significant enhancement in the specific surface area (SSA), increasing from 0.97 m<sup>2</sup>&#xa0;g⁻<sup>1</sup> for the CN to 1362.6 m<sup>2</sup>&#xa0;g⁻<sup>1</sup> for CN/MB-AC. The newly developed CN/MB-AC was then evaluated for its adsorption performance toward MB. Optimal adsorption efficiencies were achieved under experimental conditions of 1&#xa0;g&#xa0;L⁻<sup>1</sup> for CN and 0.2&#xa0;g&#xa0;L⁻<sup>1</sup> for CN/MB-AC, respectively. The adsorption kinetics were best described by the pseudo-second-order (PSO) model, while the equilibrium data were most accurately fitted by the Langmuir isotherm. Thermodynamic analysis revealed that the adsorption process was spontaneous for both materials and was associated with an increase in disorder at the MB–adsorbent interface. The process is exothermic for CN and endothermic for CN/MB-AC. Overall, the findings demonstrate the effectiveness of both materials in removing MB, with CN/MB-AC exhibiting superior performance (Q<sub>max</sub> = 357.14&#xa0;mg&#xa0;g<sup>−1</sup>) compared to raw CN (Q<sub>max</sub> = 90.09&#xa0;mg&#xa0;g<sup>−1</sup>). Furthermore, both CN and CN/MB-AC demonstrated retention of their adsorption efficiency following five successive regeneration cycles, thereby confirming their stability and suitability for repeated use in wastewater treatment processes.</p> Graphical abstract <p></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

A circular system for sustainable waste management: from cypress nut powder to activated carbon for methylene blue removal

  • 期刊论文

  • 发表日期：

    2025年8月11日

查看全文
  • Anas Salhi,
  • Sana Esserrar,
  • Zineb Naribi,
  • Imane Kasmi,
  • Mohammed El Amine Ghanjaoui,
  • Mohammed El Krati,
  • Mohammed Mountadar,
  • Soufiane Tahiri

摘要

This study focuses on developing a closed-loop system for waste management and pollutant removal, enhancing the sustainability and efficiency of treatment processes. Initially, the adsorption capacity of raw cypress nut powder (CN) for the removal of methylene blue (MB) from an aqueous medium is assessed. Once saturated with MB, the spent biosorbent underwent hydrothermal carbonization (HTC), followed by chemical activation using phosphoric acid. This process yielded an advanced material designated as CN/MB-AC. The transformation led to a significant enhancement in the specific surface area (SSA), increasing from 0.97 m2 g⁻1 for the CN to 1362.6 m2 g⁻1 for CN/MB-AC. The newly developed CN/MB-AC was then evaluated for its adsorption performance toward MB. Optimal adsorption efficiencies were achieved under experimental conditions of 1 g L⁻1 for CN and 0.2 g L⁻1 for CN/MB-AC, respectively. The adsorption kinetics were best described by the pseudo-second-order (PSO) model, while the equilibrium data were most accurately fitted by the Langmuir isotherm. Thermodynamic analysis revealed that the adsorption process was spontaneous for both materials and was associated with an increase in disorder at the MB–adsorbent interface. The process is exothermic for CN and endothermic for CN/MB-AC. Overall, the findings demonstrate the effectiveness of both materials in removing MB, with CN/MB-AC exhibiting superior performance (Qmax = 357.14 mg g−1) compared to raw CN (Qmax = 90.09 mg g−1). Furthermore, both CN and CN/MB-AC demonstrated retention of their adsorption efficiency following five successive regeneration cycles, thereby confirming their stability and suitability for repeated use in wastewater treatment processes.

Graphical abstract