Removal of phenol from simulated wastewater was investigated with silver–gold-nanoparticle-modified mango seed shell-activated carbon under batch experiment. The surface properties of the activated carbons were characterized using Fourier transform infrared spectroscopy (FTIR). Adsorption experiment was carried out at ambient temperature to study the effect of contact time, adsorbent dosage, and temperature on phenol adsorption. The equilibrium data were fitted to isotherm model, kinetic model, and intra-particle diffusion models. The maximum removal efficiencies increased from 55.5 to 94.55 and 71.4 to 98.1% for the unmodified and nano-modified activated carbon with increase concentration (50–250 mg/l). The correlation coefficient ( R 2 ) Langmuir, Freundlich, and Temkin were 0.3554–0.4563 and 0.2813–0.3191, 0.9150–0.9596 for nanoparticle-modified activated carbon (NCAMSS), as well as 0.5853–0.6598, 0.8159–0.8642, and 0.8159–0.8642, for unmodified activated carbon (UCAMSS). The R 2 of the pseudo-first and pseudo-second orders as well as Elovich kinetic models were in the ranges 0.8661–0.9925, 0.8260–0.9942, and 0.6032–0.7505 for NCAMSS as well as 0.4846–0.6032, 0.9567–0.9929, and 0.8842–0.9786, for UCAMSS and modified activated carbon, respectively, The order of fitness/suitability of the models is pseudo-first order > Elovich > pseudo-second order. The intra-particle diffusion model showed that the rate-controlling step is influenced by pore diffusion and that boundary layer diffusion and the adsorption process is heterogeneous, exothermic, and spontaneous. It can be deduced that mango seed shell is a good precursor in the production of activated due to its high yield and good adsorption capacity and the modification of the activated carbon with nanoparticles increased the precursor adsorption properties. Biosynthesises of silver/gold nanoparticles was successfully used to modify activated carbon developed from mango seed shell. The FTIR of the Mango seed shell AC and the nanoparticle-modified Mango seed shell AC indicated the presence of IR peak ranged from 729.5 to 3902.9 cm −1 and 717.8 to 3985.3 cm −1 , respectively. The adsorption results of both nanoparticle-modified and unmodified AC indicated removal efficiencies increased from 55.5 to 94.55% and 71.4 to 98.1%, respectively. Freundlich isotherm is suitable to fit the adsorption of phenol unto activated carbon produced from mango seed shell. The Δ H ° values gotten were negative which varied from − 8.8212 to − 22.8643 KJ/mol for the unmodified AC and − 3.694 KJ/mol to − 31.402 KJ/mol for nanoparticle-modified ACs. This showed that the adsorption process of phenol was spontaneous and exothermic.

中文翻译：

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微波辅助银-金纳米粒子改性芒果籽壳-活性炭吸附废水中的苯酚

用银-金-纳米颗粒改性芒果籽壳-活性炭在批量实验下研究了模拟废水中苯酚的去除。使用傅里叶变换红外光谱（FTIR）表征活性炭的表面性质。在室温下进行吸附实验，研究接触时间、吸附剂用量和温度对苯酚吸附的影响。平衡数据拟合等温线模型、动力学模型和颗粒内扩散模型。随着浓度的增加（50-250 mg/l），未改性和纳米改性活性炭的最大去除效率从 55.5% 增加到 94.55 和 71.4% 到 98.1%。相关系数 ( R 2 ) Langmuir、Freundlich 和 Temkin 分别为 0.3554–0.4563 和 0.2813–0.3191、0.9150–0。纳米颗粒改性活性炭 (NCAMSS) 为 9596，未改性活性炭 (UCAMSS) 为 0.5853–0.6598、0.8159–0.8642 和 0.8159–0.8642。NCAMSS 的准一级和准二级以及 Elovich 动力学模型的 R 2 范围为 0.8661–0.9925、0.8260–0.9942 和 0.6032–0.7505，以及 0.4846–0.6032、7,890和 0.4890.2。 –0.9786，分别对于 UCAMSS 和改性活性炭，模型的适合度/适用性顺序为伪一阶 > Elovich > 伪二阶。颗粒内扩散模型表明速率控制步骤受孔隙扩散的影响，边界层扩散和吸附过程是非均相、放热和自发的。可以推断芒果籽壳由于其高产率和良好的吸附能力而成为活性炭生产中的良好前驱体，并且用纳米颗粒改性活性炭增加了前驱体的吸附性能。银/金纳米粒子的生物合成成功地用于改性从芒果籽壳开发的活性炭。芒果种子壳AC和纳米颗粒改性的芒果种子壳AC的FTIR表明IR峰的存在范围分别为729.5至3902.9 cm -1 和717.8至3985.3 cm -1 。纳米颗粒改性和未改性活性炭的吸附结果表明，去除效率分别从 55.5% 提高到 94.55% 和 71.4% 提高到 98.1%。Freundlich 等温线适用于苯酚对芒果籽壳活性炭的吸附。得到的 Δ H ° 值为负，未改性活性炭的变化范围为 - 8.8212 至 - 22.8643 KJ/mol，纳米颗粒改性的活性炭为 - 3.694 KJ/mol 至 - 31.402 KJ/mol。这表明苯酚的吸附过程是自发放热的。