Faculty of Chemical & Petroleum Engineering, University of Tabriz, Tabriz, Iran.
Physical Inorganic Chemistry Research Laboratory, Department of Inorganic Chemistry, Faculty of Chemistry, Tabriz, Iran.
Environ Technol. 2022 Jan;43(1):116-130. doi: 10.1080/09593330.2020.1779821. Epub 2020 Jun 19.
Natural clinoptilolite (Clin) was modified with iron oxide using three different methods including precipitation, wet-impregnation and ion-exchange and then the modified adsorbent with highest As(V) removal efficiency was encapsulated into Alginate by a simple cross-linking method to obtain Fe-Clin granules. The surface morphology and chemical composition of the Fe-Clin sorbents were characterized by scanning electron microscope and X-ray diffraction analysis. The selected Fe-Clin powders and granules possessed enhanced affinity towards the highly toxic arsenic pollutant in a very short time. Batch adsorption experiments showed that the Fe-Clin adsorbent can be widely used within a wide range of pH (2-9). In addition, to reach a high removal percentage (over 90%) of As(V), the optimum dosage of powder and granule shaped adsorbents was obtained as 0.1 and 0.6 g L, respectively. Both adsorbents could successfully remove As(V) in a very short amount of time as 20 and 30 min in the case of powders and granules, respectively. The maximum adsorption capacity of Fe-Clin granules evaluated by using Langmuir adsorption isotherm was found to be 11.17 mg g. By testing the granules in a circulated fluidized column experiment, it was demonstrated that Fe-Clin granules could remove As(V) up to an acceptable level (93%) within 10 min. This study demonstrates that Fe-Clin granules, obtained by exploiting natural clinoptilolite, iron oxide and alginate, are efficient, sustainable and fairly cheap adsorbents for the removal of arsenate from the aquatic environment in a very short contact time.
天然斜发沸石（Clin）经三种不同方法（沉淀、湿浸渍和离子交换）用氧化铁改性，然后用一种简单的交联法将具有最高砷（V）去除效率的改性吸附剂包埋在藻酸盐中，得到 Fe-Clin 颗粒。通过扫描电子显微镜和 X 射线衍射分析对 Fe-Clin 吸附剂的表面形貌和化学组成进行了表征。所选的 Fe-Clin 粉末和颗粒在很短的时间内对剧毒砷污染物表现出增强的亲和力。批处理吸附实验表明，Fe-Clin 吸附剂可在很宽的 pH 值范围内（2-9）广泛使用。此外，为了达到高去除率（超过 90%）的 As(V)，分别获得了粉末和颗粒状吸附剂的最佳用量为 0.1 和 0.6 g/L。两种吸附剂都可以在很短的时间内（粉末的 20 分钟和颗粒的 30 分钟）成功去除 As(V)。通过使用 Langmuir 吸附等温线评估，Fe-Clin 颗粒的最大吸附容量被发现为 11.17mg/g。通过在循环流化床实验中测试颗粒，证明 Fe-Clin 颗粒可以在 10 分钟内将 As(V)去除到可接受的水平（93%）。本研究表明，利用天然斜发沸石、氧化铁和藻酸盐制备的 Fe-Clin 颗粒是一种高效、可持续且相当便宜的吸附剂，可在很短的接触时间内从水环境中去除砷酸盐。
