Fluoride is an impurity in nickel sulfate production,which is required for electric vehicle batteries.Hydrous zirconium oxide(HZO)was evaluated for removing fl uoride from nickel sulfate solution.Maximum fluoride remo...Fluoride is an impurity in nickel sulfate production,which is required for electric vehicle batteries.Hydrous zirconium oxide(HZO)was evaluated for removing fl uoride from nickel sulfate solution.Maximum fluoride removal occurred at pH value 4 and optimal pH value is 4–5,considering Zr solubility.Fluoride availability decreases with pH due to hydrogen fluoride and zirconium fluoride aqueous species.Fluoride removal is initially rapid,with 50 wt.%removal in 7 min,followed by slow removal up to 68 wt.%after 72 h and follows second order rate kinetics.Fluoride removal was dominated by an ion exchange mechanism and resulting Zr–F bonds were observed using Fourier-transform infrared spectroscopy.The presence of nickel sulfate decreased loading capacity compared to a salt-free solution.HZO maintained adsorption capacity through five cycles of loading and regeneration.展开更多
To understand the effect of precipitation pH and coexisting Mg^(2+) on phosphate adsorption onto zirconium oxide(ZrO_2), ZrO_2 particles precipitated at pH 5.3, 7.1 and 10.5, i.e., ZrO_2(5.3), ZrO_2(7.1)and ZrO_2(10.5...To understand the effect of precipitation pH and coexisting Mg^(2+) on phosphate adsorption onto zirconium oxide(ZrO_2), ZrO_2 particles precipitated at pH 5.3, 7.1 and 10.5, i.e., ZrO_2(5.3), ZrO_2(7.1)and ZrO_2(10.5), respectively were prepared and characterized, then their adsorption performance and mechanism in the absence and presence of Mg^(2+) were comparatively investigated in this study. The results showed that the Elovich, pseudo-second-order and Langmuir isotherm models correlated with the experimental data well. The adsorption mechanism involved the complexation between phosphate and zirconium. Coexisting Mg^(2+) slightly inhibited the adsorption of phosphate on ZrO_2(5.3), including the adsorption capacity and rate, but coexisting Mg^(2+) greatly increased the adsorption capacity and rate for ZrO_2(7.1)and ZrO_2(10.5). The enhanced adsorption of phosphate on ZrO_2(7.1) and ZrO_2(10.5) in the presence of Mg^(2+) was mainly due to the formation of Mg^(2+)-HPO_4^(2-) ion pair(MgHPO_4~0) in the solution and then the adsorption of MgHPO_4~0 on the adsorbent surface, forming the phosphatebridged ternary complex Zr(OPO_3H)Mg. In the absence of Mg^(2+) , the maximum phosphate adsorption capacity at pH 7 calculated from the Langmuir isotherm model decreased in the order of ZrO 2(7.1)(67.3 mg/g) > ZrO_2(5.3)(53.6 mg/g) ≈ ZrO_2(10.5)(53.1 mg/g), but it followed the order of Zr O2(7.1)(97.0 mg/g) > ZrO_2(10.5)(79.7 mg/g) > ZrO_2(5.3)(51.3 mg/g) in the presence of Mg^(2+) . The results of this work suggest that ZrO_2(7.1) is more suitable for use as an adsorbent for the effective removal of phosphate from municipal wastewater than ZrO_2(5.3) and ZrO_2(10.5),because Mg^(2+) is generally present in this wastewater.展开更多
采用3-氯-2-羟丙基三甲基氯化胺(CTA)对生物质秸秆进行胺基化改性获得St-N',通过正交试验确定其最佳合成条件为Na OH质量分数30%、CTA体积100 m L、反应温度80℃、反应时间3h.通过原位沉积法将纳米水合氧化锆(HZO)固载于St-N'内...采用3-氯-2-羟丙基三甲基氯化胺(CTA)对生物质秸秆进行胺基化改性获得St-N',通过正交试验确定其最佳合成条件为Na OH质量分数30%、CTA体积100 m L、反应温度80℃、反应时间3h.通过原位沉积法将纳米水合氧化锆(HZO)固载于St-N'内部,制备得到生物质基纳米HZO杂化材料St-N'-Zr.SEM、TEM、XRD与BET等技术表明纳米HZO已成功负载于StN'内部,以无定形为主,分布均匀,粒径为50~100 nm.批次吸附实验结果表明,St-N'-Zr吸附磷酸根符合Langmuir吸附等温模型,最大吸附量为33.90 mg·g-1;最佳吸附pH为1.8~6.0,可用于酸性水体除磷;强竞争离子体系中,磷去除率始终高于初始吸附量的70%,性能明显优于商用阴离子交换树脂D-201,吸附选择性良好.经10次吸附-解吸循环,再生性能良好,表明在水体磷污染深度治理领域具有一定应用潜力.展开更多
基金the financial support from the Brazilian research funding agencies Coordination for the Improvement of Higher Education Personnel(CAPES)for the postdoctoral scholarshipresearch fellow National Council for Scientific and Technological Development(CNPq-Process 308044/20185)+1 种基金Minas Gerais State Agency for Research and Development(FAPEMIG)the financial support from the University of Queensland Research Stimulus Allocation 2(Fellowships)scheme for the year of 2021 for awarding a post-doctoral fellowship。
文摘Fluoride is an impurity in nickel sulfate production,which is required for electric vehicle batteries.Hydrous zirconium oxide(HZO)was evaluated for removing fl uoride from nickel sulfate solution.Maximum fluoride removal occurred at pH value 4 and optimal pH value is 4–5,considering Zr solubility.Fluoride availability decreases with pH due to hydrogen fluoride and zirconium fluoride aqueous species.Fluoride removal is initially rapid,with 50 wt.%removal in 7 min,followed by slow removal up to 68 wt.%after 72 h and follows second order rate kinetics.Fluoride removal was dominated by an ion exchange mechanism and resulting Zr–F bonds were observed using Fourier-transform infrared spectroscopy.The presence of nickel sulfate decreased loading capacity compared to a salt-free solution.HZO maintained adsorption capacity through five cycles of loading and regeneration.
基金supported by the Shanghai Natural Science Foundation (No.15ZR1420700)the National Science Foundation of China (Nos.51408354 and 50908142)the Scientific Research Project of Shanghai Science and Technology Committee (No.10230502900)
文摘To understand the effect of precipitation pH and coexisting Mg^(2+) on phosphate adsorption onto zirconium oxide(ZrO_2), ZrO_2 particles precipitated at pH 5.3, 7.1 and 10.5, i.e., ZrO_2(5.3), ZrO_2(7.1)and ZrO_2(10.5), respectively were prepared and characterized, then their adsorption performance and mechanism in the absence and presence of Mg^(2+) were comparatively investigated in this study. The results showed that the Elovich, pseudo-second-order and Langmuir isotherm models correlated with the experimental data well. The adsorption mechanism involved the complexation between phosphate and zirconium. Coexisting Mg^(2+) slightly inhibited the adsorption of phosphate on ZrO_2(5.3), including the adsorption capacity and rate, but coexisting Mg^(2+) greatly increased the adsorption capacity and rate for ZrO_2(7.1)and ZrO_2(10.5). The enhanced adsorption of phosphate on ZrO_2(7.1) and ZrO_2(10.5) in the presence of Mg^(2+) was mainly due to the formation of Mg^(2+)-HPO_4^(2-) ion pair(MgHPO_4~0) in the solution and then the adsorption of MgHPO_4~0 on the adsorbent surface, forming the phosphatebridged ternary complex Zr(OPO_3H)Mg. In the absence of Mg^(2+) , the maximum phosphate adsorption capacity at pH 7 calculated from the Langmuir isotherm model decreased in the order of ZrO 2(7.1)(67.3 mg/g) > ZrO_2(5.3)(53.6 mg/g) ≈ ZrO_2(10.5)(53.1 mg/g), but it followed the order of Zr O2(7.1)(97.0 mg/g) > ZrO_2(10.5)(79.7 mg/g) > ZrO_2(5.3)(51.3 mg/g) in the presence of Mg^(2+) . The results of this work suggest that ZrO_2(7.1) is more suitable for use as an adsorbent for the effective removal of phosphate from municipal wastewater than ZrO_2(5.3) and ZrO_2(10.5),because Mg^(2+) is generally present in this wastewater.
