Cu-Zn-AI-CO3 layered double hydroxide （LDH）, with a Cu to Zn mole ratio of 5：1 and a （Cu＋Zn） to AI mole ratio of nearly 2, was prepared and its calcined product （CLDH） was obtained. Batch sorption studies were...Cu-Zn-AI-CO3 layered double hydroxide （LDH）, with a Cu to Zn mole ratio of 5：1 and a （Cu＋Zn） to AI mole ratio of nearly 2, was prepared and its calcined product （CLDH） was obtained. Batch sorption studies were conducted to investigate removal of phenylalanine from water with CLDH. The results show that CLDH can be used as an effective adsorbent and its sorption capacity is higher than that of Mg-A1--CO3-LDH. The maximum adsorption was observed at pH 6.7. A maximum adsorption capacity is 37.25 mg/g. The adsorption processes follow the Lagergren＇s first order kinetic model. The adsorption data are fitted well with the Langmuir isotherm equation. The thermodynamic parameters were calculated, and the negative △G and positive △H indicate that the adsorption processes are spontaneous endothermic in nature. The mechanism of adsorption also suggests that the benzoate molecules are tilted, forming an angle with the hydroxyl layers.展开更多
2D carbon ribbon/Al_(2)O_(3) was synthesized with two-dimensional metal organic frameworks 2D-MOFs as precursors using the solvothermal and calcination methods.Batch experiments of adsorption parameters such as pH,liq...2D carbon ribbon/Al_(2)O_(3) was synthesized with two-dimensional metal organic frameworks 2D-MOFs as precursors using the solvothermal and calcination methods.Batch experiments of adsorption parameters such as pH,liquid/solid ratio,adsorption kinetics,adsorption thermodynamics,and anions competitions were investigated to understand the adsorptive behavior of fluoride on carbon ribbon/Al_(2)O_(3) and nitrogen-doped carbon ribbon/Al_(2)O_(3).The adsorption of fluoride on carbon ribbon/Al_(2)O_(3) could be described as the chemical and multilayer adsorption,while the adsorption of fluoride on nitrogen-doped carbon ribbon/Al_(2)O_(3) followed the chemical and monolayer adsorption phenomenon.The fluoride on nitrogen-doped carbon ribbon/Al_(2)O_(3) had a much faster adsorption rate of 3.1×10^(−7) m/s than carbon ribbon/Al_(2)O_(3),which was 1.2×10^(−7) m/s.The nitrogen-doping on carbon ribbon enhances structural defects and improves the adsorption performance of fluoride.Also,the diacetylene linkages(—C≡C—)and pyridinic-N were studied to understand their influences on removing fluoride.The result indicates that carbon ribbon and nitrogen-doped ribbon could serve as good adsorbents for removing fluoride.展开更多
基金Project (21176263) supported by the National Natural Science Foundation of ChinaProject (2009RS3039) supported by Hunan Provincial Postdoctoral Special Foundation of ChinaProject (09JJ3026) supported by Hunan Provincial Natural Science Foundation of China
文摘Cu-Zn-AI-CO3 layered double hydroxide （LDH）, with a Cu to Zn mole ratio of 5：1 and a （Cu＋Zn） to AI mole ratio of nearly 2, was prepared and its calcined product （CLDH） was obtained. Batch sorption studies were conducted to investigate removal of phenylalanine from water with CLDH. The results show that CLDH can be used as an effective adsorbent and its sorption capacity is higher than that of Mg-A1--CO3-LDH. The maximum adsorption was observed at pH 6.7. A maximum adsorption capacity is 37.25 mg/g. The adsorption processes follow the Lagergren＇s first order kinetic model. The adsorption data are fitted well with the Langmuir isotherm equation. The thermodynamic parameters were calculated, and the negative △G and positive △H indicate that the adsorption processes are spontaneous endothermic in nature. The mechanism of adsorption also suggests that the benzoate molecules are tilted, forming an angle with the hydroxyl layers.
基金the financial supports from the Key R&D Program of Hunan Province,China(No.2018SK2026)the National Key R&D Program of China(No.2018YFC1802204)the National Natural Science Foundation of China(No.51634010).
文摘2D carbon ribbon/Al_(2)O_(3) was synthesized with two-dimensional metal organic frameworks 2D-MOFs as precursors using the solvothermal and calcination methods.Batch experiments of adsorption parameters such as pH,liquid/solid ratio,adsorption kinetics,adsorption thermodynamics,and anions competitions were investigated to understand the adsorptive behavior of fluoride on carbon ribbon/Al_(2)O_(3) and nitrogen-doped carbon ribbon/Al_(2)O_(3).The adsorption of fluoride on carbon ribbon/Al_(2)O_(3) could be described as the chemical and multilayer adsorption,while the adsorption of fluoride on nitrogen-doped carbon ribbon/Al_(2)O_(3) followed the chemical and monolayer adsorption phenomenon.The fluoride on nitrogen-doped carbon ribbon/Al_(2)O_(3) had a much faster adsorption rate of 3.1×10^(−7) m/s than carbon ribbon/Al_(2)O_(3),which was 1.2×10^(−7) m/s.The nitrogen-doping on carbon ribbon enhances structural defects and improves the adsorption performance of fluoride.Also,the diacetylene linkages(—C≡C—)and pyridinic-N were studied to understand their influences on removing fluoride.The result indicates that carbon ribbon and nitrogen-doped ribbon could serve as good adsorbents for removing fluoride.
