Comparative study of fly ash derived adsorbents, synthesis, and application

This study aimed to develop and evaluate various fly ash (FA)-derived adsorbents for TC removal, leveraging waste materials for environmental sustainability. Several adsorbents were derived from FA, including acid-modified FA (AM-FA), base-modified FA (BM-FA). and zeolite Na-P1 (ZNa-P1). Furthermore, silica nanoparticles (SiNPs) were derived from FA (FA-SiNPs) and subsequently FA-SiNPs was doped with iron to create Fe-SiNPs. Note that FA, AM-FA, BM-FA, and ZNa-P1 were tested separately to the silica nanoparticles-based adsorbents. The comparative adsorption test among FA, AM-FA, BM-FA and ZNa-P1, ZNa-P1 removed the most TC, at 90 % removal. Optimal TC removal with ZNa-P1 was achieved at 7.5 g/L dosage and pH 5. The adsorption of TC on ZNa-P1 followed pseudo-second-order kinetics and the Langmuir isotherm model, with a maximum capacity of 46.34 mg/g at 30 <b>°</b>C. The comparative adsorption tests among FA-SiNPs, SSSNPs, and Fe-SiNPs revealed that Fe-SiNPs demonstrated superior performance, removing 59 % of tetracycline. Optimal TC removal using Fe-SiNPs was achieved at a dosage of 5 g/L and within a pH range of 4-5. The adsorption of TC on Fe-SiNPs followed Elovich kinetics and the Langmuir isotherm model, with a maximum capacity of 32.31 mg/g at 30 <b>°</b>C. This study highlights the potential of FA-derived adsorbents, particularly ZNa-P1 and Fe-SiNPs, as sustainable solutions for removing TC from contaminated water. The findings contribute to advancing waste utilization strategies, particularly adsorption, for environmental remediation.

本研究旨在开发并评估多种以粉煤灰（Fly Ash，FA）为原料制备的吸附剂，用于去除四环素（Tetracycline，TC），以实现废弃物资源化利用与环境可持续发展。本研究制备的粉煤灰基吸附剂包括酸改性粉煤灰（Acid-modified FA，AM-FA）、碱改性粉煤灰（Base-modified FA，BM-FA）以及沸石Na-P1（Zeolite Na-P1，ZNa-P1）。此外，研究人员从粉煤灰中提取得到二氧化硅纳米颗粒（Silica Nanoparticles，SiNPs），并将其命名为FA-SiNPs；随后通过铁掺杂对FA-SiNPs进行改性，制备得到铁掺杂二氧化硅纳米颗粒（Fe-SiNPs）。需特别说明的是，本研究将FA、AM-FA、BM-FA及ZNa-P1与二氧化硅纳米颗粒基吸附剂分为两组分别开展吸附实验。在FA、AM-FA、BM-FA及ZNa-P1的对比吸附实验中，沸石Na-P1（ZNa-P1）对TC的去除效果最优，去除率可达90%。ZNa-P1的最佳吸附工况为投加量7.5 g/L、溶液初始pH值为5。ZNa-P1对TC的吸附动力学行为符合准二级动力学模型与朗缪尔（Langmuir）等温吸附模型，在30℃下的最大吸附容量可达46.34 mg/g。在FA-SiNPs、SSSNPs及Fe-SiNPs的对比吸附实验中，Fe-SiNPs表现出最优的吸附性能，对四环素的去除率可达59%。Fe-SiNPs的最佳吸附工况为投加量5 g/L、溶液初始pH值范围为4~5。Fe-SiNPs对TC的吸附动力学行为符合埃洛维奇（Elovich）动力学模型与朗缪尔等温吸附模型，在30℃下的最大吸附容量可达32.31 mg/g。本研究证实了粉煤灰基吸附剂（尤其是ZNa-P1与Fe-SiNPs）作为受污染水体中TC去除的可持续方案的应用潜力。本研究结果可为环境修复领域的废弃物资源化利用策略（尤其是吸附技术方向）提供理论支撑与技术参考。