Introduction

Adsorption of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) onto modified activated carbons (AC-H₃PO₄) produced from leaf biomass of Vitis vinifera leaf litter in a fixed bed column experiment was investigated in this study.

Methods

The column bed was packed with the produced activated carbons in a uniform particle size of ˃ 64 μm. Experimental parameters including the initial concentration of the solution, column bed height, the mass of adsorbent and flow rate were optimized to establish the best adsorption efficiency parameters for the system. Breakthrough and saturated time were estimated from the column fixed bed experimental data and analysed using the Adam-Bohart, Thomas model, and Yoon-Nelson models.

Results

Maximum sorption capacities of produced activated carbon ACH₃PO₄ based on Thomas model were 159.61 and 208.64 mg/g for PFOA and PFOS, respectively. The results indicated the breakthrough and saturated time of the system increased concurrently with the increase in bed height and initial concentrations, while an increase in flow rate enhanced fractional bed utilization (FBU) efficiency of the column. Thomas and Yoon-Nelson model best describe the prediction of breakthrough data and sorption behaviour of PFOA and PFOS indicating suitability of AC-H₃PO₄ column design.

Conclusion

Findings suggest that agro based adsorbent is a good alternative to non-ago based adsorbent. The surface characteristics of the phosphoric acid modified activated carbons AC-H₃PO₄ affirmed the removal of PFOA and PFOS from the contaminated water.

中文翻译：

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在固定床柱研究中使用叶生物量 (Vitis vinifera) 从水中吸附全氟辛酸 (PFOA) 和全氟辛烷磺酸 (PFOS)。

介绍

本研究在固定床柱实验中研究了全氟辛酸 (PFOA) 和全氟辛烷磺酸 (PFOS) 在由葡萄叶凋落物的叶生物质产生的改性活性炭 (AC-H ₃ PO _{4 ) 上的吸附。}

方法

柱床填充有粒径均匀的 ˃ 64 μm 的活性炭。对溶液初始浓度、柱床高度、吸附剂质量和流速等实验参数进行了优化，以确定系统的最佳吸附效率参数。根据柱固定床实验数据估计突破和饱和时间，并使用 Adam-Bohart、Thomas 模型和 Yoon-Nelson 模型进行分析。

结果

基于 Thomas 模型，生产的活性炭 ACH ₃ PO _{4的最大吸附容量分别为 159.61 和 208.64 mg/g 的 PFOA 和 PFOS。}结果表明，随着床高和初始浓度的增加，系统的穿透和饱和时间同时增加，而流速的增加提高了柱的分级床利用率（FBU）效率。Thomas 和 Yoon-Nelson 模型最能描述突破数据的预测以及 PFOA 和 PFOS 的吸附行为，表明 AC-H ₃ PO ₄柱设计的适用性。

结论

研究结果表明，基于农业的吸附剂是非基于农业的吸附剂的良好替代品。磷酸改性活性炭 AC-H ₃ PO ₄的表面特性证实了从污染水中去除 PFOA 和 PFOS。