共查询到19条相似文献,搜索用时 203 毫秒
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铝柱撑改性膨润土处理电镀废水中Cr6+的实验研究 总被引:1,自引:0,他引:1
以膨润土为原料制备了铝柱撑改性膨润土,并研究了不同影响因素对铝柱撑改性膨润土去除电镀废水中Cr6+的影响.结果表明:铝柱撑改性膨润土对Cr6+的去除率明显优于膨润土原土;废水的pH、吸附时间和膨润土投加量对Cr6+的去除率影响较大;pH=4,吸附时间为40 min,投加质量浓度为40 g/L,铝柱撑改性膨润土对Cr6+的去除率达到最大86.1%;铝柱撑改性膨润土对电镀废水中Cr6+的吸附符合Langmuir吸附等温方程. 相似文献
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以钠基膨润土为原料,制备了4种二氧化钛(TiO2)改性柱撑膨润土,并探讨了膨润土的改性方法、投土量、溶液的振荡时间、温度、pH值等因素对膨润土吸附副品红实验的影响.结果表明,4种TiO2改性柱撑膨润土对副品红的吸附效果明显好于原土;未经煅烧的TiO2改性柱撑膨润土的吸附效果要明显优于经高温(500 ℃)煅烧过的柱撑膨润土;掺杂钇的TiO2改性柱撑膨润土的吸附性能略好于未经掺杂的柱撑膨润土;膨润土投土量、溶液的振荡时间、温度和pH值均会对柱撑膨润土的吸附效果产生影响;20 ℃时,4种柱撑膨润土对溶液中副品红的吸附等温线均符合Langmuir吸附等温方程. 相似文献
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用三氯化铁、三氯化铝及硅酸钠配制了聚硅酸铝铁,研究了其作为絮凝剂对Cr(Ⅵ)的处理效果。结果表明,聚硅酸铝铁对Cr(Ⅵ)有很好的去除效果,聚硅酸铝铁投加量、pH及搅拌时间对Cr(Ⅵ)的吸附有较明显的影响。其中pH的影响最为显著。由正交试验分析得出的最佳条件为:絮凝剂质量浓度为6g/L,pH=6,搅拌t为40min时,Cr(Ⅵ)的去除率为99.77%。 相似文献
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以钙基膨润土为原料,通过柱撑改性制得两种不同的改性膨润土-铁柱撑膨润土和铝柱撑膨润土。两种膨润土分别应用于溴离子的去除当中。结果表明,两种鹏润如对溴离子的去除效果相差不大。以投加量为0.5 g为例,反应进行20 min时,溴离子的去除率已达到平衡时的90%以上。随着温度由10℃上升到45℃,铝柱撑膨润土和铁柱撑膨润土对溴离子的去除率分别由86.5%和91.7%下降到56.1%和49.6%。随着pH的升高,溴离子的去除率要显著的降低,实验条件下,选取pH 6时,效果最佳。通过吸附动力学和等温线的分析,可知改性膨润土对溴离子的吸附属于自发的放热的过程。 相似文献
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采用光沉积法制备了铂修饰TiO2柱撑膨润土光催化剂,并将其应用于含Cr(Ⅵ)废水降解还原的光催化反应。研究了废水的pH值、Cr(Ⅵ)的初始浓度、有机物等因素对含铬废水中Cr(Ⅵ)的去除率的影响。结果表明,Pt-TiO2-bentonite用量为6 g/L,废水初始pH为3.0,初始浓度为0.48 mmol/L的Cr(Ⅵ)离子,经12 W紫外灯照射反应75 min,即能达到国家排放标准,Cr(Ⅵ)的光催化还原符合L-H动力学规律,并且该复合光催化剂具有良好的沉降性能和较好的重复使用性能。 相似文献
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采用溶胶-凝胶法结合超临界流体干燥技术制备了TiO2柱撑膨润土复合光催化剂,通过XRD、BET和FT-IR等分析方法对复合催化剂的物相组成、比表面积和键合状况等物化性能进行了表征,并以Cr(Ⅵ)的光催化还原反应考察其光催化性能。结果表明,用超临界法制备的复合催化剂具有大孔、锐钛矿晶型和沉降性能好等特点,且可实现晶化、干燥一步完成;该复合催化剂的光催化活性接近P25 TiO2,且明显比空气干燥法制备的高。对于初始浓度为25 mg·L-1的Cr(Ⅵ)离子,在最佳反应条件2.5 g·L-1 TiO2 柱撑膨润土、溶液初始pH为3.0时,其光催化还原率达到77.6%。 相似文献
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三氯化铁改性膨润土对铬(Ⅵ)的吸附性能研究 总被引:3,自引:0,他引:3
通过几种不同金属盐改性的膨润土对模拟含Cr(Ⅵ)废水进行吸附实验,最终得出三氯化铁改性膨润土对cr(VI)的吸附效果最好,并着重研究了三氯化铁改性膨润土去除模拟水样中重金属离子Cr(Ⅵ)的适宜条件。结果表明,当改性膨润土用量为12g·L^-1,pH值为3~5,振荡吸附时间30min,溶液温度25%,起始Cr(Ⅵ)浓度≤20mg/L时,有机膨润土对Cr(Ⅵ)废水的去除率超过95%。 相似文献
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《分离科学与技术》2012,47(10):2177-2193
Abstract Hydrolyzed products of Al(III) have affinity below pHzpc for oppositely charged mono and bi‐nuclear species of hexavalent chromium. This study investigates the comparative performance of electrocoagulation (EC) and chemical coagulation (CC) for the removal of Cr(VI) from aqueous solution. The highest removal of Cr(VI) achieved with EC was about 42% with 4.36 mA/cm2 current density. Cathodic adsorption of chromium boosted up Cr(VI) removal during EC. Simultaneous electro‐ and chemical‐dissolution lead to high current efficiency of about 178%. Both the pH and the coagulant dosage have a significant impact on Cr(VI) removal in the pH ranges from 4.9 to 7.0. CC with alum and aluminum sulfate (AS) removed about 11% and 12% of Cr(VI). Co‐adsorption of divalent SO4 2? ions with Cr(VI) is responsible for the lower removal observed with chemical coagulants. About 0.061 and 0.099 mole of SO4 2? was adsorbed per mole Al in the precipitate in the pH range 4.9 to 7.0 with AS and alum. A higher coagulant dosage increases the removal of Cr(VI) but adversely affects the removal efficiency (Cr(VI) removed per unit of Al dosing). Cell current density (CD) has shown little effect on Cr(VI) removal and the pH elevation at the same charge density. Higher initial Cr(VI) concentration improves the removal efficiency as the species of Cr(VI) is acidic in solution and decreases the pH elevation rate. 相似文献
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Bin Li Mingxing Zhao Yanxia Qi Qidong Wang Nan Jiang Wenqin Luo 《International Journal of Applied Ceramic Technology》2021,18(5):1594-1606
A novel composite ceramsite derived from bamboo powders and bentonite was developed as adsorbents for waste water treatment. The microstructure, morphology, and thermal properties of ceramsite were characterized by X-ray powder diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray fluorescence, and differential thermal analysis. The effect of compositions, sintering temperatures, sintering time, pH, and adsorption time on the adsorption performance of the ceramsites were studied. The results revealed that the maximum Cr(VI) removal rate of 99% can be obtained in the ceramsite with weight ratio bamboo to bentonite of 6:4, the annealing temperature of 1000°C, the solution pH 1 and contact time of 12 h. The adsorption kinetics and adsorption isotherm analysis revealed that the adsorption process best followed pseudo-second-order reaction kinetics and the Freundlich adsorption isotherm. The adsorption mechanism was discussed and both chemisorption and physiosorption were proposed as adsorption mechanism of Cr(VI). Moreover, the thermodynamic parameters, including changes in Gibbs free energy, entropy, and enthalpy, were studied in detail. The bamboo powder/bentonite composite ceramsite developed in this work is a promising candidate as an effective and economical adsorbent for Cr(VI) ions removal. 相似文献