| 摘要: |
| 以水化普通硅酸盐水泥颗粒为吸附剂,研究了时间、温度和粒径等因素对其吸附PO3-4效果的影响.结果表明:在20℃,粒径0.5~1.0mm,初始PO3-4质量浓度100mg/L条件下,水化普通硅酸盐水泥颗粒吸附平衡时间为192h,平衡吸附量高达16.06mg/g;经0.25mol/L盐酸活化后,水化水泥颗粒对PO3-4的平衡吸附量增至18.54mg/g;粒径2.0~3.0mm的颗粒对PO3-4的吸附效果优于0.5~1.0mm和5.0~60mm的颗粒.吸附过程遵循假二级动力学模型,符合Freundlich等温方程.热力学解析的结果表明:酸活化水化水泥颗粒吸附PO3-4时焓变ΔH=7.56kJ/mol,熵变ΔS=0.0416kJ/（mol·K）；4,20℃的吉布斯自由能ΔG分别为-3.98,-4.65kJ/mol；酸活化水化水泥颗粒对PO3-4的吸附是一个以吸热、化学吸附为主，熵推动且自发的过程. |
| 关键词: 水化普通硅酸盐水泥 磷酸盐 吸附行为 酸活化 热力学解析 |
| DOI：10.3969/j.issn.1007 9629.2013.02.025 |
| 分类号: |
| 基金项目:住房和城乡建设部科学技术项目计划(2012 k7 21);国家水体污染控制与治理科技重大专项(2009ZX07212 002 004 003);国家自然科学基金资助项目(50830303) |
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| Behavior of Phosphate Adsorption to the Hydrated Ordinary Portland Cement |
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REN Yong xiang1, WANG Yan ping1, DUAN Xiao xing1, LIU Gang2, YANG Yong zhe1, HUANG Ting lin1
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1.School of Environmental and Municipal Engineering, Xian University of Architecture and Technology, Xian 710055, China;2.Realty Estate Company of Logistic Group, Wuhan Iron and SteelGroup Corporation, Wuhan 430080, China
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| Abstract: |
| Effects of time, temperature and particle size on phosphate adsorption by the hydrated ordinary Portland cement(HPC) were studied. The results show that the adsorption equilibrium reach in 192h and the adsorption capacity is higher than 16.06 mg/g when the temperature is 20℃, particle size is 0.51.0mm and the initial concentration is 100mg/L. The acid activation of HPC can enhance phosphate removal and the adsorption capacity of HPC subject to the treatment of 0.25 mol/L of hydrochloric acid, resulting in the adsorption capacity increased to 18.54 mg/g. Adsorption capacity of HPC with particle size of 2.03.0 mm is better than that of 0.51.0 mm and 5.06.0 mm. Kinetics data are fitted with pseudo second order model, the behaviour of phosphate adsorption on the particle of HPC could be appropriately fitted as Freundlich isotherm. Results of thermodynamic analysis on the phosphate adsorption to the particle of HPC subjected to the acid activation indicated that the adsorption heat ΔH is 7.56 kJ/mol, the entropy ΔS is 0.0416kJ/（mol·K） and the Gibbs free energy ΔG at 4℃ and 20℃ are -3.98 kJ/mol and -4.65 kJ/mol, respectively. It means that the adsorption is an endothermic and spontaneous process with entropy increase and chemisorption. |
| Key words: hydrated ordinary Portland cement(HPC) phosphate adsorption behaviour acid activation thermodynamic analysis |
