固态二氧化氯缓释剂的研究进展

固态二氧化氯缓释剂因其缓释时间长、活化率高、稳定性好的独特优势,成为消毒剂、食品加工、空气净化、蔬果保鲜等领域的研究热点。尽管许多相关研究已经实施,但针对固态二氧化氯缓释剂的类型、成分以及制备方法的系统性综述仍然缺乏。本文结合国内外二氧化氯缓释产品的研究现状,介绍了反应型和吸附型两类固态二氧化氯缓释剂的制备方法,同时也对影响二氧化氯气体的释放因素进行了分析,旨在为固态二氧化氯缓释剂的发展提供新思路。     

电子活度和pH对二氧化氯制备和稳定性的影响

建立了氯体系电子活度（pε）和pH优势区域图（pε-pH）图,从酸化、氧化和还原的角度,探讨了标准状态下pε和pH对二氧化氯制备和稳定性的影响。实际生产不可能制备绝对纯净的二氧化氯。对于不同的水体,由于其pε和pH值不同,因而可能使二氧化氯表现出不同的稳定性特征。如果水溶液中二氧化氯不歧化为氯酸根,二氧化氯相对稳定,并与亚氯酸根、氯分子或氯离子稳定共存。当氯体系实现最终平衡时,二氧化氯仅在强酸介质中优势存在,随着酸度降低,二氧化氯歧化为氯酸根和氯气,水溶性和二氧化氯在常规pH条件下不稳定。     

二氧化氯消毒剂有效氯含量的测定

二氧化氯消毒剂由于具有在消毒过程中不产生致癌物质三卤甲烷(THM),杀菌能力强等优点,在我国已开始推广应用。目前国内产品主要有两类,一类是二氧化氯发生器,通过电解食盐水生成二氧化氯、氯气、过氧化氢、臭氧等混合气体现场消毒使用;另一类是化学反应物产品,将二氧化氯气体用碱性溶液吸收,在使用时通过活化处理释放出二氧化氯气体消毒。对于化学反应物产品,有效氯含量的测定,目前尚无国家标准,给技术监督与卫生防疫在实际工作中带来不便,往往以企业标准进行产品测试。由于生产工艺等条件决定,其有效氯应为有效游离氯与有效二氧化氯。消毒剂与碘化钾在酸性条件下析出碘,用硫代硫酸钠标准溶液滴定。甘氨酸掩蔽游离氯,生成氯代氨基乙酸。     

二氧化氯与饮用水消毒

介绍了二氧化氯的性质、制备方法及其在饮用水消毒方面的应用 ,指出二氧化氯替代氯气进行饮用水消毒已势在必行。     

二氧化氯在油田污水处理中的应用研究

由于二氧化氯具有良好的氧化杀菌作用,可以有效地去除油田污水中铁、硫等具有腐蚀性和结垢性的还原性物质,以及杀灭油田污水中的各种细菌。本文考察和报告了二氧化氯在中原油田注水采油废水的应用结果,并展望了它在油田注水采油中应用前景。     

二氧化氯与饮用水消毒

介绍了二氧化氯的性质、制备方法及其在饮用水消毒方面的应用,指出二氧化氯替代氯气进行饮用水消毒已势在必行.     

二氧化氯与饮用水消毒

介绍了二氧化氯的性质、制备方法及其在饮用水消毒方面的应用，指出二氧化氯替代氯气进行饮用水消毒已势在必行。     

碘量法区分和测定二氧化氯和氯气含量

二氧化氯是一种广谱杀菌消毒剂,用于饮水消毒可减少水中致癌物三卤甲烷的产生,具有广谱、高效、快速、无毒等特性,世界卫生组织将稳定二氧化氯列为IA级高效安全消毒剂,并已在许多领域得到应用推广。测定溶液中二氧化氯含量有许多方法[1],包括电流滴定法、碘量法、紫外 可见分光光度法、流动注射分析法、极谱法等。其中碘量法对测定高含量二氧化氯效果较好,而且还能利用不同pH条件区分测定二氧化氯及其系列氧化物含量[2,3];同时碘量法所用仪器简单,一般实验室均具备测定条件,因此碘量法用于二氧化氯含量的测定被普遍采用。目前饮水消毒…     

二氧化氯的生成及其性质的微型实验

根据化学实验的微型化处理与规范化原则,对二氧化氯的制备及性质实验进行了创新设计,通过微型实验制取微量二氧化氯并检验其性质,体现了绿色化学的思想和内涵。     

氯酚红分光光度法测定水中低浓度二氧化氯

根据二氧化氯可氧化氯酚红使其褪色的特性,用示差分光光度法测定水中低浓度二氧化氯的含量。二氧化氯的浓度在0.10~0.50mg/L时,标准曲线线性较好,测定结果的相对标准偏差为1.18%~1.45%,回收率为100.6%~103.0%,该法可用于饮用水中低浓度二氧化氯的测定。     

用离子色谱法测定水中的二氧化氯、氯、亚氯酸根及氯酸根

建立了一种测定水中的ClO2、Cl2、ClO2^-、ClO3^-离子色谱法,在含有碳酸氢钠缓冲溶液的中性条件下,用NaNO2将ClO2、Cl2还原为ClO2^-、Cl^-,通过测定ClO^-和NO3^-的变化值,间接测定ClO2和Cl2。加入硫代乙酰胺(TAA)作掩蔽剂测定ClO2^-。     

Reaction of chlorine dioxide with phenol

The kinetics of phenol oxidation with chlorine dioxide in different solvents (2-methylpropan-1-ol, ethanol, 1,4-dioxane, acetone, acetonitrile, ethyl acetate, dichloromethane, heptane, tetrachloromethane, water) was studied by spectrophotometry. In all solvents indicated, the reaction rate is described by an equation of the second order w = k[PhOH]·[ClO₂]. The rate constants were measured (at 10—60 °C), and the activation parameters of oxidation were determined. The reaction rate constant depends on the solvent nature. The oxidation products are a mixture of p-benzoquinone, 2-chloro-p-benzoquinone, and diphenoquinone.     

An Electrochemical Monitor for Air Pollutants

Abstract

A thin-layer electrochemical cell has been developed as a detector for air pollutants, and tested with S0₂-air and Cl₂-air mixtures. The cell gives well-defined, reproducible signals proportional to pollutant concentrations down to 20 ppb. Two electroanalytical procedures are described for monitoring or sampling polluted air with the cell: (1) a controlled-potential experiment in which the current-time response of the cell is related to pollutant concentration, and (2) an experiment similar to stripping analysis in which pollutants are first accumulated at an electrode surface under controlled potential conditions, and then analyzed voltammetrically.     

Oxidative transformation of 1,3-dioxacycloalkanes induced by chlorine dioxide

The products and kinetic regularities of the reactions of 1,3-dioxacycloalkanes with chlorine dioxide were studied. The effects of the nature of solvent and the temperature on the reaction rate were considered and the activation parameters were determined.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1688–1692, August, 2004.Deceased.     

Oxidation of phenols with chlorine dioxide

The oxidation of different phenols, viz., phenol, 3-methylphenol, 4-methylphenol, 4-tert-butylphenol, 2-cyclohexylphenol, 2,6-di-tert-butyl-4-methylphenol, and 2,4-dichlorophenol, with chlorine dioxide in acetonitrile was studied spectrophotometrically. The reaction rate is described by a second-order equation w = k[PhOH]· [ClO₂]. The rate constants were measured and activation parameters of oxidation were determined in a temperature interval of 10–60°C. A dependence of the reaction rate constant on the phenol structure was found. The oxidation products were identified, and their yields were established.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2184–2187, October, 2004.     

Synthesis and Oxidative Transformations of New Chiral Pinane-Type γ-Ketothiols: Stereochemical Features of Reactions

Chiral γ-ketothiols, thioacetates, thiobenzoate, disulfides, sulfones, thiosulfonates, and sulfonic acids were obtained from β-pinene for the first time. New compounds open up prospects for the synthesis of other polyfunctional compounds combining a biologically active pinane fragment with various pharmacophore groups. It was shown that the syntheses of sulfanyl and sulfonyl derivatives based on 2-norpinanone are characterized by high stereoselectivity in comparison with similar reactions of pinocarvone. The conditions for the preparation of diastereomerically pure thioacetyl and thiobenzoyl derivatives based on pinocarvone, as well as for the chemoselective oxidation of γ-ketothiols with chlorine dioxide to the corresponding thiolsulfonates and sulfonic acids, were selected. The effect of the VO(acac)₂ catalyst on the increase in the yields of thiosulfonates was shown. A new direction of the transformation of thiosulfonates with the formation of sulfones was revealed. In the case of pinocarvone-based sulfones, the configuration is inversed at the C2 atom. An epimerization scheme is proposed.     

Adsorption, diffusion and desorption of chlorine on and from rutile TiO2{110}: a theoretical investigation.

The adsorption, diffusion and desorption of chlorine on and from stoichiometric, reduced and partially reduced (defective) rutile TiO2{110} are investigated using ab initio density functional theory (DFT) calculations. Theoretical results are compared with experimental investigations, and microkinetic simulations based on DFT values are then used to verify the diffusion mechanisms assumed in the experimental investigations.     

Reactions of chlorine dioxide with organic compounds. Selective oxidation of sulfides to sulfoxides by chlorine dioxide

A novel method for the selective oxidation of various types of sulfides to sulfoxides using chlorine dioxide as the oxidant is proposed.     

二氧化氯氧化降解含氨基硫脲废水研究

叶枯宁为有机硫杀菌剂 ,可用作防治水稻百叶枯病。氨基硫脲是合成叶枯宁过程中的中间体 ,在水中可溶 ,生产废水中其浓度较高 ,对水生生物有致毒作用 ,必须限制其高浓度废水排放。目前主要采用生化法处理 ,但效果不够理想。目前用于有机废水处理的氧化剂主要有Ｃｌ2 、ＣｌＯ2 、Ｏ3、氯胺等 ,其氧化能力顺序为Ｏ3>ＣｌＯ2 >Ｃｌ2 >氯胺 ,稳定性顺序为氯胺 >ＣｌＯ2 >Ｃｌ2 >Ｏ3[1 ] ,其中ＣｌＯ2 具有氧化能力强、稳定性高 ,特别是降解有机物时不发生氯代等优点 ,已被用作酚类、苯胺类、多环芳烃、印染废水等的降解处理[3～ 7] 。我们选择Ｃ…