臭氧预氧化技术在给水处理中的研究进展

介绍了臭氧预氧化技术在饮用水处理中的应用,包括臭氧预氧化助凝,臭氧预氧化改善浊度、色度、嗅味等感官指标,臭氧预氧化去除无机、有机污染物,臭氧预氧化对致病微生物、藻类、消毒副产物等的处理效果,以及臭氧预氧化在强化常规处理工艺过程中起到的作用。表明臭氧具有多方面的除污染效能,对给水处理工艺的发展和饮用水水质的提升有显著促进作用。同时也提出了存在的一些问题,便于今后的研究和应用中进一步改进和完善。     

臭氧特性及其杀灭耐热菌的应用研究

研究了臭氧在水中的溶解特性及对物体表面耐酸耐热菌的杀菌效果,以载玻片作为耐酸耐热菌的载体,采用通气悬液杀菌方式进行了单因素以及正交实验。研究结果表明：臭氧的溶解性和杀菌能力受臭氧投加量、水温、水的pH值、以及水质的影响,正交实验显示臭氧投加量为主要影响因素。     

臭氧技术处理印染废水研究进展

印染废水经二级处理后,其残余的污染物及色度仍会对环境造成很大影响。因此,高效处理技术的研发十分必要。臭氧在水中具有较高的氧化还原电位,能够降解并矿化部分有机污染物。臭氧氧化与其它水处理技术相结合产生氧化性更强的羟基自由基,能够快速、无选择性地降解有机物,是处理印染废水行之有效的方法。综述了几种高效、实用的臭氧处理技术:臭氧/紫外光法、臭氧/过氧化氢法、臭氧/活性炭法和臭氧/生物炭法。并指出了该技术在工程应用中存在的问题:反应器内泡沫的大量产生、沉淀物的生成以及臭氧对反应设备的腐蚀等。提出了开发不同处理工艺的有效组合是臭氧技术应用于印染废水处理中的研究和发展方向。     

Hydrogenated natural rubber blends: Aspect on thermal stability and oxidative behavior

Hydrogenated natural rubber (HNR) prepared from natural rubber (NR) is a new sustainable elastomer with excellent thermal properties. This study reports on the effect of vulcanization system and blend ratio on the thermal and oxidative resistance of HNR/NR vulcanizates. The various HNR/NR ratios vulcanized by peroxide and sulfur donor system exhibited the highest retention of tensile strength after thermal aging due to the formation of zinc‐dimethyldithiocarbamate (ZDMDC) which is an efficient antioxidant. The results from thermogravimetric analysis (TGA) indicated that the saturated structure of HNR had higher decomposition temperature and activation energy to enhance the thermal stability of HNR/NR vulcanizates. The initial and maximum decomposition temperatures of NR and HNR phases in vulcanizates were not affected by rubber blend ratio. This suggests that the decomposition pattern of HNR has no influence on another constituent. The increase in HNR content in the blends could retard the ozonolysis resulting in the surface cracking attacked by ozone. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Air quality monitoring in Chennai, India, in the summer of 2005

During the summer of 2005, concentrations of surface ozone (O(3)), oxides of nitrogen (NO(x)), respirrable suspended particulate matter (RSPM) and total suspended particulate matter (TSPM), relative humidity (RH), wind speed (WS) and wind direction (WD) were collected over successive periods of about 24 h at five sites. UV photometric ozone analyzer was used to measure the concentration of surface O(3). The study deals with the characteristics of hourly and daily mean surface O(3) under different climatic conditions, such as temperature, relative humidity, wind speed and wind direction and other pollutant concentrations. The maximum hourly O(3) concentration reached 53 ppb on 17th May. The ground-level O(3) concentration in Chennai varied between 2 and 53 ppb. The concentration of NO(x) and O(3) were below the prescribed limits. The TSPM values were exceeded the National Ambient Air Quality Standards (NAAQS) at Koyambedu, Mandaveli, Taramani and Vallalar Nagar study area.     

Surface ozone measurements at urban coastal site Chennai, in India

The present study was carried out to gain knowledge of current surface ozone concentrations and the effects of meteorological parameters in the highly populated urban area of Chennai, in South India. We have reported measurement results of surface ozone (O(3)) and meteorological parameters from 17th March to 10th October 2005. A photometric ozone analyzer continuously recorded the ozone concentrations at this site. The present study deals with the statistical characteristics of daily and monthly mean ozone levels under different meteorological conditions. The highest ozone concentrations were recorded in ESE-SE sectors. The monthly mean concentrations were higher in May (23+/-14 ppb) and lower in April at this site (10+/-8 ppb). The maximum hourly ozone concentration reached 69 ppb on 21st April.     

Research on quinoline degradation in drinking water by a large volume strong ionization dielectric barrier discharge reaction system

Quinoline is widely used in the production of drugs as a highly effective insecticide, and its derivatives can also be used to produce dyes. It has a teratogenic carcinogen to wildlife and humans once entering into the aquatic environment. In this study, the degradation mechanism of quinoline in drinking water by a strong ionization dielectric barrier discharge(DBD) lowtemperature plasma with large volume was explored. High concentration of hydroxyl radical(·OH)(0.74 mmol l-1) and ozone(O3)(58.2 mg l-1) produced by strongly ionized discharge DBD system were quantitatively analyzed based on the results of electron spin resonance and O3 measurements. The influencing reaction conditions of input voltages, initial p H value, ·OH inhibitors, initial concentration and inorganic ions on the removal efficiency of quinoline were systematically studied. The obtained results showed that the removal efficiency and TOC removal of quinoline achieved 94.8% and 32.2%, degradation kinetic constant was 0.050 min-1 at 3.8 k V and in a neutral p H(7.2). The proposed pathways of quinoline were suggested based on identified intermediates as hydroxy pyridine, fumaric acid, oxalic acid, and other small molecular acids by high-performance liquid chromatography/tandem mass spectrometry analysis. Moreover, the toxicity analysis on the intermediates demonstrated that its acute toxicity, bioaccumulation factor and mutagenicity were reduced. The overall findings provided theoretical and experimental basis for the application of a high capacity strong ionization DBD water treatment system in the removal of quinoline from drinking water.     

Perinatal High-Fat Diet Influences Ozone-Induced Responses on Pulmonary Oxidant Status and the Molecular Control of Mitophagy in Female Rat Offspring

Previous research has shown that a perinatal obesogenic, high-fat diet (HFD) is able to exacerbate ozone-induced adverse effects on lung function, injury, and inflammation in offspring, and it has been suggested that mitochondrial dysfunction is implicated herein. The aim of this study was to investigate whether a perinatal obesogenic HFD affects ozone-induced changes in offspring pulmonary oxidant status and the molecular control of mitochondrial function. For this purpose, female Long-Evans rats were fed a control diet or HFD before and during gestation, and during lactation, after which the offspring were acutely exposed to filtered air or ozone at a young-adult age (forty days). Directly following this exposure, the offspring lungs were examined for markers related to oxidative stress; oxidative phosphorylation; and mitochondrial fusion, fission, biogenesis, and mitophagy. Acute ozone exposure significantly increased pulmonary oxidant status and upregulated the molecular machinery that controls receptor-mediated mitophagy. In female offspring, a perinatal HFD exacerbated these responses, whereas in male offspring, responses were similar for both diet groups. The expression of the genes and proteins involved in oxidative phosphorylation and mitochondrial biogenesis, fusion, and fission was not affected by ozone exposure or perinatal HFD. These findings suggest that a perinatal HFD influences ozone-induced responses on pulmonary oxidant status and the molecular control of mitophagy in female rat offspring.     

Influence of Related Factors on 03 Generating Characteristics in Airowater-soild Mixture Plasma Reactor

双脉冲放电等离子体水处理技术是一种有效的水处理方法,利用产生的活性物种能高效降解多种有机大分子污染物。针对复杂混合体等离子体反应器中气相O3生成情况进行了研究,重点考察了脉冲电压、曝入气体体积流量、不同的填料特性（粒径和表面粗糙度）等条件对水处理时生成O3的影响。实验结果表明,生成O3质量浓度随着放电电压增加而增大,随着曝入气体体积流量的减小而增加。填入不同粒径的填料生成O3质量浓度也有所不同,其中填充粒径9mm的填料时O3质量浓度最大。另外,粒径相同,但表面峰密度大的填料在生成O3时也表现出更好的特性。     

空气放电产生臭氧的研究

在臭氧产生机理分析的基础上 ,实验研究了功率、气量、气压和气体湿度对臭氧和NOx 产生的影响。结果表明 ,在一定范围内随着功率增加或气体流量减少 ,臭氧体积分数增加 ,臭氧产生效率降低 ,NOx 和NOx/O3 相对体积分数增大 ;一定条件下 ,随着气压增加 ,臭氧体积分数降低 ,NOx/O3 相对体积分数先减少后增加 ;湿度降低 ,臭氧产生体积分数提高 ,NOx/O3 相对体积分数减少。