Belaye Mitin, Taddesse Abi M, Teju Endale, Sanchez-Sanchez Manuel, Yassin Jemal M
Department of Chemistry, Haramaya University, P.O.Box 138, 138 Dire Dawa, Ethiopia.
Instituto de Catálisis y Petroleoquímica (ICP), CSIC, C/Marie Curie 2, 28049 Madrid, Spain.
ACS Omega. 2023 Jun 16;8(26):23860-23869. doi: 10.1021/acsomega.3c02290. eCollection 2023 Jul 4.
The discharge of inorganic pollutants like phosphate and fluoride is a cause of mounting concern to the world due to the substantial environmental and human health risk. Adsorption is one of the most common and affordable technologies widely utilized for removing inorganic pollutants such as phosphate and fluoride anions. Investigating efficient sorbents for the adsorption of these pollutants is extremely important and challenging. This work aimed at studying the adsorption efficiency of the Ce(III)-BDC metal-organic framework (MOF) for the removal of these anions from an aqueous solution using a batch mode. Powder X-ray diffraction (XRD), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) techniques evidenced the successful synthesis of Ce(III)-BDC MOF in water as a solvent without any energy input within a short reaction time. The outstanding removal efficiency of phosphate and fluoride was exhibited at an optimized pH (3, 4), adsorbent dose (0.20, 0.35 g), contact time (3, 6 h), agitation speed (120, 100 rpm), and concentration (10, 15 ppm) for each ion, respectively. The experiment on the effect of coexisting ions demonstrated that SO and PO ions are the primary interfering ions in phosphate and fluoride adsorption, respectively, while the HCO and Cl ions were found to have interfered less. Furthermore, the isotherm experiment showed that the equilibrium data fitted well with the Langmuir isotherm model and the kinetic data correlated well with the pseudo-second-order model for both ions. The results of thermodynamic parameters such as Δ°, Δ°, and Δ° evidenced an endothermic and spontaneous process. The regeneration of the adsorbent made using water and NaOH solution showed the easy regeneration of the sorbent Ce(III)-BDC MOF, which can be reused four times, revealing its potential application for the removal of these anions from aqueous environment.
由于存在重大的环境和人类健康风险，磷酸盐和氟化物等无机污染物的排放引起了全球越来越多的关注。吸附是广泛用于去除磷酸盐和氟化物阴离子等无机污染物的最常见且经济实惠的技术之一。研究用于吸附这些污染物的高效吸附剂极其重要且具有挑战性。这项工作旨在研究Ce(III)-BDC金属有机框架（MOF）在间歇模式下从水溶液中去除这些阴离子的吸附效率。粉末X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、热重分析（TGA）、布鲁诺尔-埃米特-泰勒（BET）和扫描电子显微镜-能量色散X射线分析（SEM-EDX）技术证明，在短反应时间内，以水为溶剂，无需任何能量输入，成功合成了Ce(III)-BDC MOF。在每种离子的优化pH值（3、4）、吸附剂剂量（0.20、0.35 g）、接触时间（3、6 h）、搅拌速度（120、100 rpm）和浓度（10、15 ppm）下，分别表现出对磷酸盐和氟化物的出色去除效率。共存离子影响实验表明，SO和PO离子分别是磷酸盐和氟化物吸附中的主要干扰离子，而HCO和Cl离子的干扰较小。此外，等温线实验表明，平衡数据与朗缪尔等温线模型拟合良好，动力学数据与两种离子的准二级模型相关性良好。诸如Δ°、Δ°和Δ°等热力学参数的结果证明该过程是吸热且自发的。用水和氢氧化钠溶液对吸附剂进行再生表明，吸附剂Ce(III)-BDC MOF易于再生，可重复使用四次，揭示了其在从水环境中去除这些阴离子方面的潜在应用。
