Abstract：
With variable atomic ratios, Ce-Al bimetallic oxides were fabricated using the sol-gel combustion method and utilized for efficient fluoride removal. The synthesized bimetallic oxides were extensively studied using advanced characterization techniques, including TGA, XRD, FTIR, BET surface area analysis, EDX-assisted FESEM, XPS and impedance analysis. These techniques facilitate the interpretation of the chemical and physical properties of the synthesized material. The Ce-Al (1:1) bimetallic oxide was selected as an adsorbent for the defluoridation. The Ce-Al (1:1) oxide demonstrates a moderately high surface area of 108.67 m2/g. The sorption behaviour of fluoride on Ce-Al (1:1) was thoroughly investigated using batch and column modes. The maximum fluoride removal efficiency (99.4%) was achieved at a temperature of 45 °C and pH of 7.0 using an adsorbent dose of 0.18 g/L for 35 min. Pseudo-second-order kinetic model appropriately describes the sorption process. Freundlich\'s adsorption isotherm was more pertinent in representing fluoride adsorption behaviour. The maximum fluoride adsorption capacity is 146.73 mg/g at 45 °C. Thermodynamics study indicates fluoride adsorption on Ce-Al (1:1) bimetallic oxide is spontaneous and feasible. The adsorption mechanism was interpreted through XPS spectra, indicating that the physisorption process is mainly responsible for fluoride adsorption. An in-depth investigation of the adsorption dynamics was carried out using mass transfer models and found that the external diffusion process limits the overall adsorption rate. An electrochemical investigation was performed to understand the effect of fluoride adsorption on the electrochemical behaviour of bimetallic oxide. The fixed-bed column adsorption study suggested that the lower flow rate and increased bed height favourably impacted the overall defluoridation process, and column adsorption results were suitably interpreted through both the Adam-Bohart model and Yoon-Nelson dynamics model. The sustainable aspect of the defluoridation process was elucidated in terms of carbon footprint measurement using life cycle assessment analysis. The carbon footprint of the entire treatment process was calculated as 0.094 tons/year.
摘要：
随着可变原子比，使用溶胶-凝胶燃烧法制备Ce-Al双金属氧化物，并将其用于有效去除氟化物。使用先进的表征技术对合成的双金属氧化物进行了广泛的研究，包括TGA,XRD,FTIR,BET表面积分析，EDX辅助FESEM，XPS和阻抗分析。这些技术有助于解释合成材料的化学和物理性质。选择Ce-Al（1：1）双金属氧化物作为脱氟的吸附剂。Ce-Al(1:1)氧化物显示108.67m2/g的中等高表面积。使用分批和色谱柱模式彻底研究了氟化物在Ce-Al（1：1）上的吸附行为。在45°C的温度和7.0的pH下，使用0.18g/L的吸附剂剂量持续35分钟，可实现最大的氟化物去除效率（99.4％）。伪二级动力学模型恰当地描述了吸附过程。Freundlich的吸附等温线在表示氟化物吸附行为方面更为相关。45℃时的最大氟化物吸附容量为146.73mg/g。热力学研究表明，氟化物在Ce-Al（1：1）双金属氧化物上的吸附是自发且可行的。通过XPS谱解释了吸附机理，表明物理吸附过程主要负责氟化物的吸附。使用传质模型对吸附动力学进行了深入研究，发现外部扩散过程限制了整体吸附速率。进行了电化学研究，以了解氟化物吸附对双金属氧化物电化学行为的影响。固定床柱吸附研究表明，较低的流速和增加的床高度有利地影响了整个脱氟过程，并通过Adam-Bohart模型和Yoon-Nelson动力学模型对色谱柱吸附结果进行了适当解释。使用生命周期评估分析在碳足迹测量方面阐明了脱氟过程的可持续方面。整个处理过程的碳足迹计算为0.094吨/年。
