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1.
一种高效的圆盘板式臭氧发生器   总被引:1,自引:1,他引:1  
本文介绍臭氧的应用领域及其作用机理,对一种新型臭氧发生器的结构、原理及其技术参数进行了系统分析。  相似文献   

2.
臭氧-催化技术治理低浓度气体污染物   总被引:1,自引:0,他引:1  
在对臭氧-催化技术及其发展现状评述的基础上,分别考察了铂-钯催化剂(Pt-Pd/Al2O3)对DMMP、CH4、C6H6、F22、CO催化氧化和臭氧催化 氧化的反应性能。结果表明,催化作用和臭氧催化氧化作用所要求的反应温度范围相近并低于250℃,才能很好地协同作用。臭氧-催化技术竽起燃温度低、易氧化气体污染物的处理。  相似文献   

3.
饮用水臭氧氧化处理过程中溴酸根的产生及控制   总被引:2,自引:1,他引:1  
论述了给水处理中溴酸根(BrO3-)的健康危害、产生机理、影响因素及其控制和去除方法。采用臭氧氧化处理含溴离子(Br-)水时,会产生以BrO3-为主的臭氧化副产物。BrO3-的生成与Br-初始浓度、臭氧投加量、水温、无机碳浓度、水中天然有机物(NOM)的种类和浓度、以及水的pH值等因素有关。目前研究较多的削减BrO3-...  相似文献   

4.
以北京市某水厂砂滤池出水为实验原水,研究了臭氧曝气时间对实验原水中天然有机物(NOM)性质、结构及氯化消毒副产物生成的影响。通过高效凝胶色谱、三维荧光光谱、红外光谱等检测分析方法对水中NOM进行表征后发现,经臭氧作用后水样DOC浓度升高、亲水性增加、芳香性及重均分子量下降。有机物中羟基、碳碳双键或碳氮双键及其共轭体系、脱质子羧基官能团与氯反应活性较强。综合考虑臭氧作用后NOM性质、结构变化及氯化消毒副产物生成量的改变,选择最佳臭氧接触时间为12 min。  相似文献   

5.
臭氧对混凝剂形态及功能的影响   总被引:1,自引:0,他引:1  
应用Ferron逐时络合比色法,从铝形态分布及其转化的角度,研究了臭氧对聚合氯化铝混凝性能影响并探究其原因。结果表明,预臭氧对聚合氯化铝(PAC)的混凝效果有显著影响。在一定质量浓度范围内(0~3.60mg/L),臭氧浓度越高,水样浊度越高(其UV254(即254nm波长下水样的紫外吸光度值,表征含芳香环结构和共轭双键结构的有机物含量)和溶解性有机碳(DOC)的去除效果较显著)。臭氧对混凝剂水解形态有显著影响。预臭氧后,混凝絮体形成和浊度的去除与铝混凝剂中中等聚合态铝(Alb)的含量有关,Alb的含量越高,浊度去除效果越好。因此,臭氧剂量的增加抑制Alb生成可能是导致浊度升高的一个重要原因。  相似文献   

6.
沸石载体催化剂研制及其催化臭氧氧化染料废水的研究   总被引:1,自引:0,他引:1  
以沸石为载体负载不同金属氧化物来制备催化剂,通过试验分析该催化剂催化臭氧氧化染料废水的效果及其影响因素。结果表明:(1)沸石对染料废水的吸附作用很小,总有机碳(TOC)去除率基本维持在3.2%左右,对于后期的试验可以忽略其影响。(2)以沸石作为载体制得的MnO2、Fe2O3、ZnO、CuO负载型催化剂(分别简写为MnO2/沸石、Fe2O3/沸石、ZnO/沸石、CuO/沸石),对臭氧氧化反应均有催化作用,其催化效果依次为MnO2/沸石Fe2O3/沸石ZnO/沸石CuO/沸石。同时,MnO2/沸石的重复使用率高。(3)MnO2/沸石催化臭氧氧化效率及重复使用率均优于以活性炭为载体的MnO2负载型催化剂。(4)臭氧氧化和MnO2/沸石催化臭氧氧化对染料的脱色率基本一致。MnO2/沸石催化臭氧氧化的TOC去除率比臭氧氧化提高较多,对染料废水有很好的处理效果。(5)以沸石为载体制得的负载型催化剂催化臭氧氧化实际染料废水的处理效果较好,具有较高的实用价值。  相似文献   

7.
采用介质阻挡强电离放电技术制取高浓度臭氧 ,使用射流器和气液溶解分离器溶解臭氧制取高浓度臭氧水。讨论了应用臭氧量、气液比、系统压力和气液溶解方式对臭氧水浓度和臭氧有效溶解效率的影响  相似文献   

8.
臭氧水中传质模型的研究   总被引:4,自引:0,他引:4  
在传统鼓泡塔中对臭氧在水中的传质过程进行实验研究。利用实验改变进水流量、臭氧进气流量以及臭氧进气浓度等,得到臭氧传质系数、臭氧传质效率和臭氧消耗等有关参数。建立一个臭氧传质模型,可以预测不同操作条件下臭氧传质效率,从而优化控制臭氧化反应动力学。  相似文献   

9.
针对活性炭催化臭氧化降解低质量浓度含氰废水体系,研究了活性炭吸附、催化作用在催化臭氧化体系中的作用,提出了吸附-催化臭氧化协同作用机理。在活性炭-臭氧体系中,活性炭吸附CN-的能力很弱,活性炭在反应体系中主要起了吸附、催化臭氧的作用。活性炭-臭氧体系降解CN-的过程是臭氧直接氧化、活性炭吸附臭氧与活性炭催化臭氧产生.OH自由基间接氧化三者共同作用的结果。  相似文献   

10.
珠三角秋季臭氧污染来源解析   总被引:4,自引:0,他引:4  
秋季是珠三角臭氧污染最严重的季节,选取2004年秋季珠三角典型臭氧污染过程,运用臭氧来源解析技术等分析手段,研究珠三角臭氧污染特性,分析并量化各排放源区各类源对受体点的臭氧贡献。结果表明,东莞市对珠江口地区的臭氧峰值有重大贡献,下午2-3点东莞市前体物的臭氧贡献最大可达40ppb;而广州市区的前体物排放主要影响顺德区和南海区。在珠三角,排放源区一般对下风向40km范围内的地区臭氧贡献最大。秋季大多数情况下珠三角西部(江门东湖)臭氧受中部主要排放源区臭氧前体物排放与输送的影响很大,广州和佛山地区对江门东湖的臭氧峰值贡献达50ppb左右。交通尾气排放对珠三角各受体点的臭氧贡献最大,交通源对重污染区受体点臭氧的贡献最高可达40ppb~50ppb。  相似文献   

11.
2012年6—10月,在我国北方某焦化厂厂界附近开展了O3、NO x、CO体积分数在线监测及VOCs样品采集分析工作,获得了夏、秋两季焦化厂厂界O3及其前体物的体积分数及其日变化趋势。焦化厂厂界附近O3、NO、CO体积分数均呈单峰型日变化,O3体积分数的季节差异不明显,夏季仅略高于秋季,而NO、CO体积分数秋季高于夏季,作为二次反应产物的NO2,其变化幅度秋季比夏季强烈。夏季TVOCs在各监测时段的小时体积分数呈现先上升后下降的日变化趋势,而秋季则呈现逐渐下降的日变化趋势。由较小VOCs/NO x的比值可初步判断,该焦化厂所在区域的大气光化学臭氧生成潜势处于VOCs控制区。在焦化厂下风向厂界附近,夏、秋两季TVOCs平均体积分数分别为(43.8±45.0)×10-9和(26.7±29.6)×10-9,苯系物、烷烃、烯烃的平均体积分数分别为(34.3±28.1)×10-9和(14.4±14.8)×10-9、(5.3±11.8)×10-9和(7.0±7.7)×10-9、(4.3±5.0)×10-9和(5.3±7.1)×10-9。夏、秋两季焦化厂附近臭氧生成潜势贡献最大的是苯系物(47.6%~65.8%),其次是烯烃(28.0%~41.9%),再次是烷烃(6.3%~10.5%)。  相似文献   

12.
An analysis of surface ozone measurements at a west coast site in northern California (Trinidad Head) demonstrates that this location is well situated to sample air entering the west coast of the US from the Pacific Ocean. During the seasonal maximum in the spring, this location regularly observes hourly average ozone mixing ratios 50 ppbv in air that is uninfluenced by the North American continent. Mean daytime values in the spring exceed 40 ppbv. A location in southern California (Channel Islands National Park) demonstrates many of the characteristics during the spring as Trinidad Head in terms of air flow patterns and ozone amounts suggesting that background levels of ozone entering southern California from the Pacific Ocean are similar to those in northern California. Two inland locations (Yreka and Lassen Volcanic National Park) in northern California with surface ozone data records of 20 years or more are more difficult to interpret because of possible influences of local or regional changes. They show differing results for the long-term trend during the spring. The 10-year ozone vertical profile measurements obtained with weekly ozonesondes at Trinidad Head show no significant longer-term change in tropospheric ozone.  相似文献   

13.
14.
GOAL, SCOPE AND BACKGROUND: Great interest in the unprecedented events of the major, sudden stratospheric warming and the ozone hole split over Antarctica in September 25, 2002 motivates a necessity to analyze the current understanding on the dynamics, chemistry and climate impacts that are associated with both events. METHODS: Significant progress in the analysis of the observational data obtained, as well as successful development and application of dynamical modeling, which have been achieved very recently, create a basis for the first survey on the role of the major, sudden stratospheric warming observed in the southern hemisphere and its relationship to the diminutive Antarctic ozone hole and its break up into two parts. RESULTS AND DISCUSSION: Special attention has been paid to assessments of the causes of the major warming event and the future expectations concerning the stratospheric ozone depletion effect. Among the principal results is the fact that, as the polar vortex elongated, it became hydrodynamically unstable, and this insta-, bility affected the upper troposphere and stratosphere. During the major, sudden stratospheric warming, the middle stratospheric vortex split into two pieces; one piece rapidly mixed with extra vortex air, while the other returned to the pole as a much weaker and smaller vortex. The polar night jet was considerably weaker than normal, and was displaced more poleward than has been observed in previous winters, resulting from a series of wave events (propagated from the troposphere) that took place over the course of the winter. Finally, the relative ozone decrease (increase) in the eastern Antarctic is tightly associated with westerly (easterly) zonal wind anomalies near the southern tip of South America, and the unusual behavior of the ozone hole in 2002 therefore appears to be caused by great easterlies in this region. CONCLUSIONS: The main conclusion is that the southern polar vortex and the diminutive ozone hole split into two parts in September 2002, due to the prevalence of very strong planetary waves, led to the appearance of a major, sudden stratospheric warming. Although there is evidence that sea surface temperature anomalies contributed to the excitation of the quite strong planetary waves over Antarctica in 2002, there is not yet a widely approved mechanism supporting that. RECOMMENDATIONS AND OUTLOOK:The appearance of the near-record size of the 2003 ozone hole confirmed that the 'no-ozone-hole' episode observed in the year 2002 does not denote a recovery of the ozone layer. Despite the current successful attempts to get a sufficient understanding for the genesis of both extraordinary events, more observations and further modeling efforts are necessary to more reliably assess the contribution of various dynamic mechanisms to the recently observed tropo-stratospheric surprises.  相似文献   

15.
介绍了一种多功能电化学臭氧发生器,根据需要可产生臭氧化氧气,也可直接制得臭氧水.试验表明,该发生器十分适合用于家庭室内空气的净化和增氧、卫生间的消毒灭菌、蔬菜水果残余农药的去除、酚嗅的去除等用途,具有很好的开发前景.  相似文献   

16.
17.
The Mediterranean environment, and most of the Italian peninsula, presents some peculiarities in terms of crop response to O3 since most physiological mechanisms activated upon O3 exposure, such as stomatal closure, often overlap and interact with those that underlie plant adaptation to drought and hyperosmotic stress, which are typical of these environments. OTC and EDU experiments have demonstrated that O3 causes strong yield losses when crops are grown without water limitations. However, exposure to water or saline stress significantly reduced O3 effects on crop yield. In this review, we present the methodological approaches that have been used to study plant-ozone interactions in Italy as well as biochemical, physiological and agronomic responses for representative cropping systems of the Mediterranean climate.  相似文献   

18.
在对采自云南滇池水华蓝藻细胞中的微囊藻毒素-RR(microcystin-RR,MC-RR)提取并发现其含量达到0.19mg/g(干重)的基础上,重点研究了臭氧氧化降解所提取的MC-RR。结果表明,当反应体系中臭氧浓度为5.7 mg/L时,初始浓度1.9 mg/L的MC-RR在15 min内被完全降解。利用HPLC/ESI/MS对提取的MC-RR及其氧化降解产物质荷比测定发现,降解前MC-RR的质谱图中出现特征离子m/z=1 038.7、m/z=519.8以及m/z=135.0。而降解后的产物质谱图中只有Adda基团中带苯环结构化合物(C9H10O)的特征离子峰m/z=135.0存在,其他2个离子峰完全消失。由此推断反应体系中MC-RR(m/z=1 038.2)在大量臭氧及其.OH自由基全面攻击下,分子结构中Adda基团以及单环结构中的不饱和双键直接被氧化而发生断链,最终形成小分子的有机物。  相似文献   

19.
To investigate short-term effects of ambient ozone exposure on mortality in Chinese cities, we conducted a meta-analysis of 10 effect estimates of 5 short-term studies, which reported associations between ambient ozone and mortality in Chinese mainland cities. And we estimated pooled effects by non-accidental mortality, cardiovascular mortality, and respiratory mortality. Combined estimates and their 95%CI were tested by RevMan 5, and Funnel plots were used for the bias analysis. For a 10 μg m−3 increase of maximum 8-h average concentration of ozone, the percent change for non-accidental mortality, cardiovascular mortality, and respiratory mortality were 0.42 (95%CI, 0.32–0.52%), 0.44% (95%CI, 0.17–0.70%) and 0.50% (95%CI, 0.22–0.77%), respectively. Compared with pooled estimates from other meta-analyses on ambient ozone-associated mortality, our pooled estimate for non-accidental mortality was slightly higher than previous ones and pooled estimate for cardiovascular mortality was consistent with others. However, we observed significantly positive association between ambient ozone and respiratory mortality, which were generally nonsignificant in earlier studies. By combining estimates from published evidence, a small but substantial association between ambient ozone level and mortality was observed in Mainland China.  相似文献   

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