Abstract

This study describes the preparation of nanoporous activated carbons from the agricultural waste of peach stones. These materials were utilized as adsorbents for removing imidacloprid pesticide from aqueous media. Two types of activated carbons (PSAC 300 and PSAC 500) were synthesized via chemical activation with orthophosphoric acid followed by pyrolysis at 300 and 500 °C, respectively. Brunauer, Emmet, and Teller (BET) analysis revealed a mesoporous structure for PSAC 500 with lower surface area and pore volume than that of the microporous PSAC 300. Both PSAC 300 and PSAC 500 successfully removed imidacloprid with removal efficiencies of about 80% and 99%, respectively, at 10 mg/L of imidacloprid and pH 5.2, while PSAC 500 exhibited a maximum adsorption capacity of 39.37 mg/g. Fourier transform infrared (FTIR) spectroscopy measurements along with thermodynamic calculations inferred that physisorption occurred via hydrogen bonding and pi–pi stacking. The two activated carbons were successfully regenerated and reused for three consecutive cycles. This work has implications for waste valorization and production of value-added products from waste.

摘要

本研究描述了从桃核的农业废弃物制备纳米多孔活性炭。这些材料被用作吸附剂，用于从水性介质中去除吡虫啉农药。通过用正磷酸进行化学活化，然后分别在 300 和 500 °C 下热解，合成了两种类型的活性炭（PSAC 300 和 PSAC 500）。Brunauer、Emmet 和 Teller (BET) 分析显示 PSAC 500 具有比微孔 PSAC 300 更低的表面积和孔体积的介孔结构。 PSAC 300 和 PSAC 500 均成功去除吡虫啉，去除效率分别为 80% 和 99% %，分别为 10 mg/L 吡虫啉和 pH 5.2，而 PSAC 500 的最大吸附容量为 39.37 mg/g。傅里叶变换红外 (FTIR) 光谱测量以及热力学计算推断物理吸附是通过氢键和 pi-pi 堆叠发生的。两种活性炭成功再生并重复使用三个连续循环。这项工作对废物价值化和从废物中生产增值产品具有重要意义。