Reactions of Aqueous Chlorine and Chlorine Dioxide with Lipids: Chlorine Incorporation

Various lipids were reacted with HO³⁶Cl and ³⁶ClO₂ in an aqueous medium, and the extent of incorporation of ³⁶Cl into the lipids was determined. Cl incorporation into lipids treated with HOCl was greater than lipids treated with ClO₂. Free fatty acids incorporated more Cl than their corresponding esters. The degree of Cl incorporation was directly correlated with number of double bonds in the lipid. Triglycerides behaved as esters of their component fatty acids. High Performance Liquid Chromatography (HPLC) studies indicated at least two chlorinated products were formed from the reaction of HO³⁶Cl with oleic acid.     

Chlorine Incorporation in Shrimp

Chlorine incorporation into shrimp was determined following immersion in a 150 mg/L solution of HO³⁶Cl. Approximately 2% of the ³⁶Cl in the original immersion solution was incorporated into the shrimp during the 30-min immersion period; 75% of which was detected in the edible portion. Approximately 3% of the chlorine associated with the edible portion was detected in the CHCl₃:CH₃OH soluble fraction. Data indicated that chlorine incorporation in lipids is directly related to the degree of unsaturation. The trichloroacetic acid (TCA) precipitable protein fraction contained 22% of the ³⁶Cl associated with the edible portion. Seventy-three percent of the chlorine associated with the edible shrimp tissue existed as ³⁶Cl^?. Negligible amounts of chlorine were detected in the control fractions.     

电位滴定法测定漂白废水中总有机氯化物的研究

利用电位滴定法测定漂白废水中的氯离子用银量法简单，终点判断容易，准确度高。以Ｓｃｈｏｎｉｇｅｒ燃烧法和电位滴定法测定漂白废水中的总有机氯化物，操作简单、准确度较高、测定时间短且费用低，适于国内纸厂日常检测。     

Bactericidal Activity of Aqueous Chlorine and Chlorine Dioxide Solutions in a Fish Model System

A commercial ClO₂-producing solution killed mostly Escherichia coli, Listeria monocytogenes Scott A and its streptomycin-resistant (Str^R) strain at 15, 10, and 7.5 ppm, respectively, while aqueous ClO₂ and chlorine achieved similar results against the tested strains at 20 and 25 ppm, respectively. Aqueous ClO₂ and the commercial solution were more effective than aqueous chlorine in killing Str^R-L. monocytogenes inoculated on fish cubes (mangrove snapper) at 3.4 × 10³ or 2.4 × 10⁶ CFU/g, as well as in solutions washed off the cubes. Fish cubes treated with aqueous chlorine or ClO₂ contained negligible chlorine residues, while the commercial treatment samples contained chlorite and some free and combined available chlorine.     

不同施氯量对烤烟氯含量和产质量的影响

研究了不同施氯量对烟株氯含量、积累量及烤后烟叶产质量的影响。结果表明,随施氯量上升,烟株氯含量和积累量均表现为显著上升的趋势,整株氯含量和积累量与施氯量呈极显著的正相关。施氯量从0kg/hm~2提高到48kg/hm~2时,上部叶中的氯明显增加;但施氯量进一步增加到96 kg/hm~2时,中部叶和下部叶中的氯增加较为显著;茎和根中的氯随施氯量增加而表现出下降的趋势。施氯量在24 kg/hm~2时,烤后烟叶产质量较好,化学成分较为协调,不施氯或施氯太高均不利于烟叶质量的提高。     

Mutagenicity and Identification of the Reaction Products of Aqueous Chlorine or Chlorine Dioxide with L-Tryptophan

Nonvolatile products generated from reactions of graded molar ratios of aqueous chlorine or chlorine dioxide with L-tryptophan (1:1, 3:1 and 7:1) were shown to be direct-acting mutagens to Salmonella typhimurium TA100 and TA98. Increasing the ratio of disinfectant relative to amino acid led to increased mutagenic activity, with mutagenicity highest at the 7:1 molar ratio. Several fluorescent bands obtained after thin layer chromatographic fractionation of the reaction mixtures were shown to be more mutagenic than the reaction mixtures. GC/MS analysis of the compounds in a highly mutagenic fraction of the aqueous chlorine reaction products identified 1,1,3-trichloropro-panonc, 1,1,3,3-tetrachloropropanone and dichloroquinoline.     

Fate of Chlorine During Flour Chlorination

Unbleached flour (pH 5.8) was treated with ³⁶Cl₂ (g) in a closed-system flour chlorinator to pH levels of 5.25, 4.41, and 4.01. Of the total active Cl₂ generated (12.38, 20.71 and 28.17 mg, respectively), 98.6–99.6% was shown to react with the flour. Only 0.35–1.37% was recovered in NaOH traps. Extraction of the treated flour with chloroform showed that 27.0–33.7% of the total ³⁶Cl was incorporated into flour lipids, of which 31.2–39.1% of the radioactivity went to nonpolar lipids and 60.9–68.8% to polar lipids. The water-insoluble and water-soluble fractions of defatted flour contained 17.9–21.4% and 2.1–4.7% of the total ³⁶Cl, respectively. The remaining ³⁶Cl (40.3–49.1%) was present as ³⁶Cl^-.     

Chlorine Generation and Disinfection by Electroflotation

Electroflotation is a promising technology for simultaneous disinfection and removal of floatable constituents of food process water or fluid products. A bench‐scale electroflotation apparatus was constructed. The device demonstrated that disinfection was affected by the presence of chloride and the applied current. It was effective in disinfecting Escherichia coli when chloride was present at levels at least 5.6 mg L¹ at 0.8 A but not at 0.1 A even with 260 mg L^?1 chloride. Experiments on salt solutions showed that chlorine generation efficiency increased with chloride up to 260 mg L^?1 and also with current, reaching a constant value above 0.4 A. Gas generation efficiency was relatively constant. Appropriate selection of operating conditions may allow optimization of disinfection and separation in electroflotation.     

氯气风机优化设计方案

文章叙述了15万t/a离子膜烧碱装置氯气处理生产工艺原理及工艺流程;该装置现运行生产状况,针对出现的问题,查找原因,找到解决办法;通过对工艺、设备的技术改造,达到节能降耗,稳定生产。     

用二氧化氯和臭氧组合预漂

二氧化氯对木素的选择性强，是一种极好的漂白剂。而在TCF漂白中，所用化学品在脱木索同时都对纤维索产生降解作用，但环境保护和市场的需要又不得不采用TCF法漂白纸浆，故要生产高强性能的化学浆，二氧化氯的应用不容忽视。在TCF漂白中，臭氧(O2)是很有效的氧化剂，可以氧化各种类型结构的木素，但O2也可氧化多糖链形成羰基和羧基。在碱处理时，这类基团可引起断链而降低浆料黏度。因此，O2通常用于漂白顺序的开始，这是由于大量木索的存在而阻止了纤维索的降解。     

添加醛改进二氧化氯漂白

为达到目标卡伯值，在第1段漂白用ClO2全部替代氯会增加漂白成本。在D0段添加醛，可有效改善ClO2脱木素效果。当Do段浆中甲醛用量1．5％（对绝干浆）时，第1段抽提后，卡伯值降低30％，并可减少ClO2在流程中的用量。此外，文中还讨论了ClO2脱木素过程中形成的亚氯酸盐的作用。     

改良ClO2热漂白工艺

目前，ClO2热漂自已经成为阔叶术硫酸盐浆第一段漂白的首选。该技术在2002年率先被巴西的一家纸浆厂采用。世界上最新的6条阔叶木硫酸盐浆漂白生产线中就有5条采用ClO2热漂白(ClO2漂白初始阶段温度为85～90℃，停留时间为120-180min)。     

二氧化氯在食品行业中的应用

对近几年来国内外将二氧化氯（ClO2）应用于食品行业的研究概况进行了综述，包括杀菌消毒、食品保鲜、环境除臭三个方面。ClO2具有很强的氧化作用，能够有效杀死微生物，是一种高效安全的杀菌消毒剂；可阻止蛋氨酸生成乙烯，破坏已生成的乙烯，并对动植物机体不产生毒效，在食品保鲜中具有独特的性能优势；可与异味物质（H2S、-SOH、-NH2等）发生脱水反应，使其迅速氧化为其他物质，具有高效的除臭作用。     

应用二氧化氯保鲜烧鸡

探讨天然黄色素对熟肉制品的防腐作用.用不同浓度黄色素水溶液及加热煮沸、晾凉后的黄色素水溶液处理熟驴肉块,35℃培养自然生菌72h,分别统计霉斑数、霉菌孢子体数目,计算病情指数.油菜花黄色素溶液浓度在0.05%以上对熟驴肉具有显著的防腐性,但经加热煮沸后防腐作用降低.     

全无氯漂白生产实践

本文介绍了永丰纸业全无氯漂白生产线的工艺流程、设备特征,试生产中遇到的问题及解决措施,并就实施该项目对环境、产品质量、经济和社会效益进行了评价.     

提高二氧化氯得率的生产实践

介绍Ｒ８法ＣｌＯ２制备工艺,分析影响ＣｌＯ２得率的因素,提出提高ＣｌＯ２得率的有效措施     

纸浆漂白用二氧化氯生产过程控制系统

介绍了一种二氧化氯生产过程控制系统.该系统采用工业控制计算机、可编程序控制器(PLC)及现场仪表相结合构成过程控制系统,实现生产过程自动化.系统采用现场总线技术,结构简单,操作方便,运行可靠.     

烟草分析用氯溶液标准物质

为了保证连续流动法测定烟草中氯结果的准确性和可溯源性,选择一级标准物质氯化钠为原料,经定量称取和定体积溶解,安瓿瓶分装和热封,研制出氯溶液标准物质.该标准物质经均匀性、稳定性检验,并用重量法定值,其质量浓度为0.1001 mg/mL.对影响该标准物质不确定度的质量、纯度、体积、均匀性、稳定性等因素进行了分析,其不确定度为0.0005 mg/mL.