吴昊
,
孙丽娜
,
王辉
,
王晓旭
环境化学
doi:10.7524/j.issn.0254-6108.2016.04.2015110101
本文探讨了利用过氧化钙活化过硫酸钠氧化修复实际污染场地长期高浓度石油类(TPH)污染土壤的可行性.研究了过氧化氢、过氧化钙、过氧化钙/Fe2+等活化方法对TPH降解效率的影响.结果表明,对于TPH污染较重的土壤(浓度15000 mg·kg-1),过氧化钙较过氧化氢活化过硫酸钠降解的效果更好,使用过氧化氢活化方法,TPH最高降解率仅为25.6％,而当过氧化钙/过硫酸钠的用量(物质的量之比)为1/5时,反应7d,TPH去除率达到67.4％,反应不需要添加额外的活化剂.当Fe2+/过氧化钙/过硫酸钠的用量为1/2/5时,反应7d,TPH降解率为82.1％,较不添加Fe2+高14.6％,反应后体系呈中性.进一步增加过氧化钙的用量,TPH去除率和体系pH均增加.研究表明,CaO2/Fe2+活化过硫酸钠氧化修复石油类污染土壤效果较好,考虑到实际场地后续利用的可行性,Fe2+/过氧化钙/过硫酸钠的用量为1/2/5较为合适.
关键词:
活化过硫酸钠
,
过氧化钙
,
石油类
,
土壤修复
Weizhen OUYANG
,
Xia CAO2
,
Ning WANG
金属学报(英文版)
The aim of this article was to theoretically study diffusion and migration of chloride ions during electrochemical chloride removal. The proposed model would enable optimization of its application by predicting the optimal treatment time and current combination. A mathematical model for simulating the transport behavior of chloride ions was developed by consideration of diffusion and migration of chloride ions when a constant DC current density was applied through the marine cast iron artifacts. The corresponding tests were conducted to validate the mathematical model. This model predicted the data of the extraction ratio of the chloride ion that correlated satisfactorily with the experimental values. An important issue in electrochemical chloride removal was to understand how chloride ions moved, taking account of diffusion and migration of chloride ions and the release of binding chloride ions. The effects of the treatment time, externally applied current density, chloride diffusion coefficient, and rate constant of release of binding chloride ion on chloride removal are studied. The specific quantitative details applied to one-dimensional model were discussed here. This article has proposed a mathematical model for the first time, which was showed to be a useful tool that can reveal the ionic transport mechanism and optimize the application during electrochemical chloride removal.
关键词:
Marine cast iron
,
null
,
null
邹元爔
,
赵彭年
,
曹兆民
金属学报
利用石灰的加碳还原反应,设计了一个新的研究方法,以直接测定液态高炉型渣中CaO的活度.这一方法的成功,依靠溶剂金属的正确选择以降低熔液中钙的化学位,而使金属钙量提高到可以用化学分析测定的水平.我们估计钙在锡稀溶液中的活度系数很小,可能符合于我们的要求,因此研究了下列反应:CaO+C(石墨)=Ca(锡)+CO(气).以测定液态CaO-SiO_2和CaO-Al_2O_3-SiO_2渣中CaO的活度,在上式中符号下波纹线表示溶于渣中的组分,直线表示溶子金属中的组分,下同.对于CaO-Si0_2系,应用Gibbs-Duhem关系从CaO活度值算出了SiO_2的活度值,并根据一个统计力学模型讨论了活度曲线的形状.从CaO-Al_2O_3-SiO_2系的研究结果,可知在所研究的整个碱度范围內,渣中存在10%Al_2O_3都使CaO的活度增加;当Al_2O_3为20%时,则对CaO活度的影响视碱度不同而异.对Al_2O_3的这种行为,根据炉渣的离子结构理论提出了解释.
关键词:
张子青
,
周继程
,
邹元燨
,
田彦文
金属学报
本文以Sn为溶剂金属,直接用“渣-金属”化学平衡法,在较大组成范围内测定了CaO-Si0_2-Al_2O_3三元熔渣中CaO的活度。成功地用图示推测法推测了较难直接获得实验结果的低CaO浓度范围内CaO的活度。应用本文实验结果和数据分析得到了该渣系中较全面的等CaO活度曲线图,并对Al_2O_3在该渣系中的酸碱性行为进行了探讨。
关键词:
王保文
,
郑瑛
,
贺铸
,
宋侃
,
郑楚光
工程热物理学报
钙基吸收剂煅烧-碳酸化循环法(CCRs)是一种新兴的分离燃煤锅炉尾部烟气中CO2的方法.CaO与CO2碳酸化反应对于CCRs法的应用起着非常重要的作用.本文采用随机孔隙模型(RPM)对CaO与CO2碳酸化反应过程进行了研究,结果表明,适当提高CaO与CO2碳酸化反应的温度和系统压力,增加CaO吸收剂的初始孔隙率、优化CaO的初始比表面积等措施能够有效提高CaO碳酸化转化率和对CO2的吸收容量.
关键词:
煤燃烧
,
CO2分离
,
CaO碳酸化反应
,
数值模拟
,
随机孔隙模型(RPM)
Yanwen TIAN
,
Yuchun ZHAI
,
Xin ZHANG
材料科学技术（英文）
The activity of VO in molten ternary CaO-SiO2-VO slag has been determined by chemical equilibrium method, using tin as the solvent metal. The relation between the activity and the content of VO, as well as the effect of slag basicity on activity of VO, are discussed.
关键词:
Electrochimica Acta
Some fundamental aspects related to inert anode development in molten CaCl(2)-CaO were investigated based on thermodynamic analysis, electrochemistry of metals and solubility of oxide measurements. The Gibbs free energy change of several key anodic reactions including electro-stripping of metals, electro-formation of metallic oxides, electro-dissolution of metallic oxides as well as oxygen and chlorine evolution was calculated and documented, for the first time, as a reference to develop metallic inert anode in chloride based melts. The anodic behaviors of typical metals (Ni, Fe, Co, Mo, Cu, Ag, and Pt) in the melt were investigated. The results confirmed the thermodynamic stability order of metals in the melts and revealed that surface oxide formation can increase the stability of the electrodes in CaO containing melt. Furthermore, solubility of several oxides (NiO, Fe(2)O(3), Cr(2)O(3), Co(3)O(4), NiFe(2)O(4)) in pure CaCl(2) or CaCl(2)-CaO melts was measured to evaluate the stability of oxide coating or a cermet inert anode in the melt. It was found that the solubility of NiO decreased with increasing CaO concentration, while that of Fe(2)O(3) increased. Ni coated with NiO film had much higher stability during anodic polarization. (C) 2011 Elsevier Ltd. All rights reserved.
关键词:
Inert anode;Anodic behavior;Chloride melts;Solubility of oxide;cryolite-alumina melts;electrochemical reduction;calcium-chloride;nickel ferrite;cao-cacl2 melt;part i;electrolysis;titanium;solubility;mechanism
Zeitschrift Fur Naturforschung Section a-a Journal of Physical Sciences
This paper presents a cluster approach to the calculation of the g factors for 3d(7) ions in cubic octahedral crystals, in which the parameters related to the configuration interaction and the covalency reduction effects are obtained from optical spectra of the studied crystals, and so no adjustable parameters are applied. From the approach, the g factors for MgO:Co2+ and CaO:Co2+ are calculated. The calculated results show good agreement with the observed values. The experimental values of g < 4.333 (the first order value in absence of configuration and covalency interactions) for MgO:Co2+ and g > 4.333 for CaO:Co2+ are also explained.
关键词:
electron paramagnetic resonance (EPR);crystal-field theory;Co2+ ion;MgO;CaO
胡英杰
,
程继健
硅酸盐通报
doi:10.3969/j.issn.1001-1625.1999.02.012
采用Sol-gel方法制备出新型SiO2-TiO2-BaO-CaO耐碱涂层.合成了适合于浸涂工艺的稳定溶胶涂液.红外光谱表明:醋酸与钛离子形成稳定的配位体,从而延长了凝胶时间;500℃处理后,凝胶中已形成氧化物网络.通过测定侵蚀后涂膜玻璃的失重量和原子吸收光谱,分析组成和热处理温度对涂层耐碱性的影响.XRD图谱和SEM照片表明:涂膜玻片经NaOH侵蚀后,表面形成富钛保护层,提高耐碱性,而侵蚀后生成的复杂晶体使侵蚀加剧.
关键词:
sol-gel工艺
,
SiO2-TiO2-BaO-CaO系统
,
浸渍涂层
,
耐碱性
,
防护膜
