Synthesis of a Novel Ce-bpdc for the Effective Removal of Fluoride from Aqueous Solution

Abstract

Ce-1,1 -biphenyl-4,4 -dicarboxylic acid (Ce-bpdc), a novel type of metal organic framework, was synthesized and applied to remove excessive fluoride from water. The structure and morphology of Ce-bpdc were measured by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The effects, such as saturated adsorption capacity, HCO 3 − , and pH, were investigated. The optimal pH value for fluoride adsorption was the range from 5 to 6. The coexisting bicarbonate anions have a little influence on fluoride removal. The fluoride adsorption over the Ce-bpdc adsorbent could reach its equilibrium in about 20 min. The Ce-bpdc coordination complex exhibited high binding capacity for fluoride ions. The maximum adsorption capacity calculated from Langmuir model was high up to 45.5 mg/g at 298 K (pH = 7.0) and the removal efficiency was greater than 80%. In order to investigate the mechanism of fluoride removal, various adsorption isotherms such as Langmuir and Freundlich were fitted. The experimental data revealed that the Langmuir isotherm gave a more satisfactory fit for fluoride removal. Finally, the tested results of ground water samples from three places, Yuefang, Jiangji, and Sanyi which exhibited high removal efficiency, also demonstrate the potential utility of the Ce-bpdc as an effective adsorbent.

Room‐Temperature Aerobic Oxidation of Amines to Nitriles over Ruthenium Oxide Supported on CeO2 Derived from MOFs

“…The catalyst BPDC−RuO 2 −CeO 2 and its precursor were characterized by XRD. XRD diffraction peaks of Ce−BPDC [36] are shown in Figure 5a, which indicates that the synthesized Ce−BPDC has excellent crystallinity [37] . Then, from the XRD patterns of BPDC−RuO 2 −CeO 2 (Figure 5b), we can note that its peak shapes and diffraction angles are completely different from those of Ce−BPDC.…”

“…The synthesis of CeÀ BPDC was according to the previously reported method, [36] in a round bottom flask 4, 4'-biphthalic acid (H 2 BPDC, 7.5 mmol) was dissolved in 30 mL deionized water and stirred violently to make it completely dispersed. Then sodium hydroxide solution (15 mL, 1 mol • L À 1 ) was added into the above solution and the mixture was stirred continuously until the Na 2 BPDC solid precipitation was formed.…”

Performance of metal–organic frameworks for the adsorptive removal of potentially toxic elements in a water system: a critical review

“…This represented a PC value of 1.54 L g À1 and a removal efficiency greater than 80%. 155 Furthermore, Ce-bpdc removed uoride from groundwater samples taken from Yuefang, Jiangji, and Sanyi in China with a removal efficiency of 78, 64, and 50%, respectively, indicating the potential of Ce-bpdc to be an effective adsorbent for this purpose.…”

Next‐generation organometallic adsorbents for safe removal of excessive fluoride from aqueous systems

“…To avoid the effects of OH − , the pH of the solution was adjusted to 7.0. 35 Generally, multivalent anions are more competent than monovalent anions. Moreover, multivalent anions had negative effects, possibly because they were involved in stronger electrostatic interactions with the positively charged adsorbents, which may be the reason for reduced fluoride removal in the presence of SO 2− 4 .…”