在ClO2预漂段加次氯酸清除剂以减少氯酸盐的生成

在二氧化氯（ClO2）脱木素和漂白中会生成氯酸盐,使总的ClO2用量损失20％～36％。而氯酸盐不同木素反应,因此生成氯酸盐降低了C1O2的效率。另外氯酸盐是众所周知的除莠剂和杀菌剂,有些国家已经控制它的排放。因此,在ClO2漂白时,应该寻找有效的方法以减少氯酸盐的生成。     

减少二氧化氯生产损失的措施

我厂的二氧化免（ClO2）制备系统全套引进加拿大STERLING公司R8技术，DCS自动控制。该系统工艺先进，操作方便，生产成本低，具有优良的生产适应性。其化学反应式如下：影响ClO2得率，使生产成本上升的主要原因是生产过程损失，因此必须对生产中的各种损失进行分析、比较，并采取行之有效的解决措施，努力降低成本，达到生产最佳化。ClO2生产中的过程损失主要有：发生器母液雾沫夹带，芒硝携带，过滤机滤液飞失，排气损失以及如母液暴沸、泄漏、ClO2分散等其他损失。各种过程损失对反应效率的影响为：母液露珠夹带＞过滤机滤液飞先…     

二氧化氯脱木素和漂白化学中的无机中间反应

介绍了ClO2脱木素和漂白过程中产生的一系列化学反应及其中间产物（包括亚氯酸盐、氯酸盐、次氯酸、一氧化氯自由基等）,并对中间产物的生成、转化及其对ClO2漂白效率的影响进行了归纳,结合ClO2漂白工艺及ECF漂白流程优化方面的进展,揭示了反应机理对工艺优化的指导作用,旨在为进一步提高ClO2漂白效率提供理论依据。     

ERCO-R系列二氧化氯制备技术的特点及适用性

描述了ERCO-R系列ClO2制备技术的生产工艺,分析了ClO2各种制备技术的特点,根据我国环保要求结合R系列ClO2制备技术的特点,阐明了ClO2制备技术选择应用的原则.     

水相体系酶法制备甘油磷脂酰乙醇胺的研究

研究了水相体系中脂肪酶Thermo 4S-3水解大豆粉末磷脂制备甘油磷脂酰乙醇胺(L-α-GPE)的可行性,探讨了反应条件对磷脂酰乙醇胺(PE)转化率和L-α-GPE得率的影响.确定脂肪酶Thermo4S-3催化制备L-α-GPE的最佳反应条件为:pH 7,底物质量浓度5 mg/mL,反应温度40℃,酶添加量30 U/mL,CaCl2添加量3.33 mg/mL,反应时间6h.在最佳反应条件下,PE转化率为95.5％,L-α-GPE得率为93.6％.     

ClO_2制备食用马铃薯氧化淀粉工艺研究

选用新型、安全、高效、稳定的氧化剂制备马铃薯氧化淀粉,通过工艺参数优化实验确定其工艺参数最优水平为:ClO2用量为淀粉质量的0.12%(以ClO2计),LXF型专用活化剂为ClO2原液的10%,反应时间5 h,反应温度50℃。     

酶解制备玉米肽的工艺优化研究

为了高效制备玉米肽,对玉米蛋白粉进行超声预处理,以多肽得率为评价指标,从Protamex、Alcalase、Flavourzyme、Protex.7 L、胰蛋白酶、木瓜蛋白酶等6种蛋白酶中筛选出Alcalase为最佳水解用酶.通过单因素试验和响应面分析确定制备玉米肽的工艺条件为:底物浓度10.0 g/(100 ml)、加酶量2 830 U/g、反应pH9.0、反应温度58.0℃、反应时间3h.在该条件下制备的玉米酶解产物的多肽得率为(46.61±0.37)％,与理论预测值的相对误差在±1％以内.     

酶法制备甘油磷酸胆碱的研究

研究了水相体系中磷脂酶A<,1>水解大豆粉末磷脂制备甘油磷酸胆碱(GPC)的可行性,探讨了反应条件对磷脂酰胆碱(PC)转化率和GPC得率的影响.确定磷脂酶A<,1>催化制备GPC的最佳反应条件为:在pH 7的150 mL磷酸盐缓冲溶液中,粉末磷脂添加量5 g、CaCl2添加量0.50 g、酶添加量0.50 mL,温度55 ℃,反应时间6 h;利用LC-MS分析最佳条件下的反应液,得到PC转化率为98%,GPC得率达到95%;同时验证了在磷脂酶A<,1>催化制备GPC的过程中生成的溶血磷脂(LPC)Sn-2位不饱和脂肪酸发生了酰基转移,转移到Sn-1位.     

ClO2漂液的制备与应用

介绍了国产第1套ClO2漂液制备装置、ClO2漂液的制备及其漂白应用效果.     

干法制备木薯磷酸酯淀粉的研究

以木薯淀粉为原料，三聚磷酸钠为酯化剂，采用干法制备磷酸酯淀粉，考查了反应时间、反应温度、pH值，三聚磷酸钠和尿素用量时磷酸酯淀粉的取代度和反应效率的影响。结果表明：干法制备磷酸酯淀粉的最佳工艺条件为：反应温度130～150℃、反应时间1．5h、pH5～6、三聚磷酸钠用量7％～9％、尿素用量2％，取代度和反应效率可分别高达0．075和61．60％以上。     

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     

脱墨纸浆中荧光增白剂与ClO2的反应性

对采用ClO2 漂白脱墨纸浆时纸浆中的荧光增白剂与ClO2 的反应性进行了研究。结果表明 :在脱墨纸浆的漂白过程中 ,H2 O2 漂剂可以提高脱墨纸浆的白度 ,但不能有效去除浆中的荧光增白剂 ;ClO2 漂剂可以有效去除浆中的荧光增白剂 ,但经其漂白处理后纸浆的白度下降。在ClO2 漂白脱墨纸浆时 ,ClO2 可以氧化纸浆中的荧光增白剂 ,使其降解为酸类物质 ,从而使浆中的荧光增白剂得到去除。     

Oxidation of the cyanobacterial hepatotoxin microcystin-LR by chlorine dioxide: reaction kinetics, characterization, and toxicity of reaction products

Cyanobacteria are known producers of cytotoxins, hepatotoxins, and neurotoxins. The main toxins are microcystins, cyclic heptapeptide hepatotoxins, produced by strains of several cyanobacterial genera frequently found in eutrophied freshwaters. Due to the acute and chronic toxicity of microcystins, successful removal of these toxins in drinking water treatment processes is of increasing concern. In the present work the kinetics of microcystin-LR (MC-LR) oxidation by chlorine dioxide (ClO2) was studied with UV-spectrometry and high performance liquid chromatography (HPLC). Characterization of reaction products was performed with mass spectrometric (MS) analysis, while the toxicity of reaction products was tested with a protein phosphatase inhibition assay (PPIA). The main reaction products formed, dihydroxy isomers of MC-LR as identified by MS, were nontoxic according to the PPIA. The overall rate constant k for the reaction between MC-LR and ClO2 at 293 K and pH 5.65 was modest, k = 1.24 M(-1) s(-1), suggesting that ClO2 is not a suitable oxidant for the degradation of microcystins in drinking water treatment processes.     

麦草浆DEP漂白过程中污染物产生规律研究

研究了麦草化学浆DEP漂白过程中麦草浆性能变化情况,以及漂白废水中污染物生成规律,并建立了二氧化氯用量、纸浆得率等因素与漂白废水中污染物发生量的相关关系式。结果表明：随着二氧化氯用量的增加,漂白废水中CODCr、BOD5、AOX发生量都逐渐增加,并且这些污染物发生量与二氧化氯、得率和白度等有密切的关系。     

TiO2热喷涂层在ClO2水溶液中的耐蚀性

以化学反应动力学为基础，利用重量法测定了TiO2热喷涂层在ClO2水溶液介质中的腐蚀速度，从而求出了TiO2热喷涂层的单位厚度寿命。实验表明，TiO2热喷涂层在ClO2水溶液中的腐蚀速度满足VL=kc^1.1(mm/a）的动力学方程式，从而为TiO2热喷涂层在ClO2水溶液中的防腐蚀提供了理论依据。     

气体二氧化氯对葡萄杀菌效果及品质的影响

以‘巨峰’葡萄为试材,从其表面分离优势菌并鉴定其为大肠杆菌与考克氏菌,利用NaClO₂与干冰间接反应开发一种气体二氧化氯(ClO₂)处理方法以灭活葡萄表面优势菌,通过测定菌落总数对数值减少量评估气体ClO₂对葡萄的杀菌效果,同时通过测定4℃贮藏30 d期间葡萄样品的色泽参数、果实硬度、质量损失率以及可溶性固形物含量评估气体ClO₂对葡萄品质的影响。结果表明,气体ClO₂处理对接种于葡萄表面的大肠杆菌与考克氏菌具有良好杀灭效果。当ClO₂累积浓度从131μL/(L·h)提升至599μL/(L·h),大肠杆菌菌落总数对数值减少量从1.6(lg(CFU/g))升至3.5(lg(CFU/g)),考克氏菌菌落总数对数值减少量从1.0(lg(CFU/g))升至4.5(lg(CFU/g))。与对照组(S0)相比,经ClO₂处理后贮藏30 d期间葡萄色泽并没有明显变化,与S0和低累积浓度处理组(S1)相比,高累积浓度处理组(S2)在4℃贮藏30 d后...     

Atmospheric DMSO degradation in the gas phase: Cl-DMSO reaction. Temperature dependence and products

The reactions of Cl atoms and ClO radicals with CH3-SOCH3 (DMSO) have been studied using the discharge flow method with direct detection of DMSO, CO, and products by mass spectrometry. The absolute rate constant at room temperature measured for reaction 1, (CH3)2SO + Cl --> products, was k(1) = (1.7 +/- 0.3) x 10(-11) cm3 molecule(-1) s(-1). For reaction 2, (CH3)2SO + ClO --> products, only an upper limit could be established, k(2) < or = 6 x 10(-14) cm3 molecule(-1) s(-1) Reaction 1 has been found to proceed through adduct formation and further decomposition involving the cleavage of the C-S bound. The pressure effect on the Cl-DMSO reaction from 0.5 to 3 Torr was negligible, and the temperature dependence in the range 273-335 K was also very slight. The results obtained are related to previous studies of sulfur compounds, and the atmospheric implications are also discussed in relation to the homogeneous sinks of DMSO. Tropospheric lifetimes of DMSO based on average Cl and ClO concentrations and the measured rate constants have been calculated showing that the contribution of reaction 1 must be of minor relevance in the marine boundary layer. Reaction 2 is so slow that it does not play any role within the atmospheric sulfur chemistry.     

二氧化氯氧化处理邻联甲苯胺模拟废水的研究

以邻联甲苯胺去除率为考察指标,采用正交法研究了二氧化氯对邻联甲苯胺模拟废水的氧化处理。确定了最优化工艺条件为：水温25℃、二氧化氯与邻联甲苯胺的化学计量比4：1、pH值7．0,反应时间控制在70min左右,结果表明,二氧化氯氧化法去除废水中邻联甲苯胺污染物是可行的,o—TD去除率超过92％。     

Oxidation of the cyanobacterial hepatotoxin microcystin-LR by chlorine dioxide: influence of natural organic matter

Cyanobacteria (blue-green algae) are known producers of cytotoxic, hepatotoxic, and neurotoxic compounds with severe acute and chronic effects on vertebrates. Successful removal of these toxins in drinking water treatment is therefore of importance for public health. In the present work the oxidation of the cyanobacterial hepatotoxin microcystin-LR (MC-LR) by chlorine dioxide (ClO2) was studied at natural microcystin concentrations (10 microg L(-1)) and normal ClO2 dosages (1 mg L(-1)) in the absence and presence of natural organic matter (NOM). ClO2 was found to be rapidly consumed by fulvic and humic acids, leaving less residual ClO2 to oxidize MC-LR. Predicted decrease rates in MC-LR concentration correlated highly with experimental data both in pure water and in the presence of NOM. Rate constants determined at high ClO2 and MC-LR concentrations in pure water could be used to predict the oxidation of MC-LR at natural concentrations. Toxicity tests with a protein phosphatase inhibition assay on reaction solutions and high-performance liquid chromatography fractions revealed that PP1 enzyme inhibition emerged only from intact MC-LR, while the oxidation products, dihydroxy isomers of MC-LR, were nontoxic even at unnaturally high concentrations.     

二氧化氯氧化水中质子态联苯胺的反应机制

联苯胺类化合物是一类具有致基因突变、致癌性且在环境中广泛存在的有毒有害物质。以联苯胺作为代表性有机污染物,采用UV-vis、IR及GC/MS等方法研究了ClO2氧化水中质子态联苯胺的反应机理。指出了溶液pH值与联苯胺存在型体的关系,当pH值低于3.57时,溶液中联苯胺是以双质子态为主要存在形式的;控制溶液pH值2.0,对ClO2氧化水中质子态联苯胺的反应中间产物进行了鉴定。结果表明,该氧化反应中间产物依次为联苯醌二亚胺、联苯醌二肟和联苯醌,联苯醌最终被氧化成不饱和酸;通过分析ClO2与有机物反应特点和联苯胺分子结构的特性,在单电子转移理论的基础上,探讨了ClO2氧化质子态联苯胺可能的反应历程。