A convenient one-step synthesis of mesoporous ZrO 2 /SBA-15 and its uranium adsorption properties
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A convenient one‑step synthesis of mesoporous ZrO2/SBA‑15 and its uranium adsorption properties Li Chen1 · Wenping Yang1 · Xinmiao He1 · Enchao Wang1 · Qiang Xian1 · Hui Dan1 · Wenkun Zhu1 · Yi Ding1 Received: 4 May 2020 © Akadémiai Kiadó, Budapest, Hungary 2020
Abstract Mesoporous ZrO2/SBA-15 materials were prepared for the first time by a one-step method using ZrO2 as zirconium source and their uranium (U(VI)) adsorption behavior were studied. The influence of Z rO2 content on the structure, morphology and hydrothermal stability of the obtained Z rO2/SBA-15 was investigated. It was found that the structural order of Z rO2/SBA-15 decreased with increasing ZrO2 content. The hydrothermal stability of SBA-15 was improved by loading of ZrO2. Furthermore, the effects of pH, initial U(VI) concentration, contact time, temperature and ZrO2 content on the U(VI) adsorption capacity were studied. The results demonstrated that the U(VI) adsorption capacity decreased with increasing Z rO2 content and temperature. The adsorption process was found to be well fitted to the Langmuir and pseudo-second-order model. The calculated maximum adsorption capacities were 326 and 294 mg·g−1 for 0.4ZrO2/SBA-15 and 0.8ZrO2/SBA-15 samples at 283 K, respectively. Furthermore, the analysis of thermodynamic parameters (ΔG, ΔH, and ΔS) revealed that the process of U(VI) adsorption onto ZrO2/SBA-15 was feasible, spontaneous and exothermic. Keywords ZrO2/SBA-15 · One-step method · Radioactive waste water · Uranium · Adsorption
Introduction With the development of nuclear science and technology, a large amount of radioactive waste water will be inevitably produced. If not treated effectively, it is harmful to the environment and human beings [1]. Uranium is one of the major pollutants in radioactive waste water. The harm of uranium to human body comes from two aspects: chemical and radiation toxicity which can cause damage to the human kidney, immune and nervous system [2]. At present, a large number of methods were used to treat uranium-containing wastewater [3–7]. Among them, the adsorption method was considered as a radioactive wastewater treatment method with great development potential because of its advantages of low cost, easy design, simple equipment, convenient operation, * Yi Ding [email protected] Wenkun Zhu [email protected] 1
Key Subject Laboratory of National Defense for Radioactive Waste and Environmental Security, Southwest University of Science and Technology, Mianyang 621010, People’s Republic of China
high purification rate and low energy consumption [8, 9]. Up to now, different types of absorbents have been explored for the adsorption of uranium including active carbon [10], zeolite [11] and clay [12]. However, these adsorbents exhibit low adsorption capacity and slow adsorption rate because of its small pore size and low specific surface area. Thus, development of effective adsorbents to remove uranium from radioactive waste water is particularly indispensable. Mesoporous SBA-15 materials, one of the
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