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951.
游泳是一项健康的体育活动,但同时也增加了与病原微生物和消毒药/副产品暴露接触的风险.鉴于康乐体育游泳运动的普及,值得洋意的是,我们对游泳池化合物、人体暴露和潜在的健康风险的理解仅处于初级阶段而已.归绺其原因部分是由于游泳池水化学的复杂性,当水从源头流向泳客的时候增加了它在水中的转化  相似文献   
952.
Problems due to the taste and odor in drinking water are common in treatment facilities around the world. Taste and odor are perceived by the public as the primary indicators of the safely and acceptability of drinking water and are mainly caused by the presence of two semi-volatile compounds – 2-methyl isoborneol (MIB) and geosmin. A review of these two taste and odor causing compounds in drinking water is presented. The sources for the formation of these compounds in water are discussed alongwith the health and regulatory implications. The recent developments in the analysis of MIB/geosmin in water which have allowed for rapid measurements in the nanogram per liter concentrations are also discussed. This review focuses on the relevant treatment alternatives, that are described in detail with emphasis on their respective advantages and problems associated with their implementation in a fullscale facility. Conventional treatment processes in water treatment plants, such as coagulation, sedimentation and chlorination have been found to be ine ective for removal of MIB/geosmin. Studies have shown powdered activated carbon, ozonation and biofiltration to be e ective in treatment of these two compounds. Although some of these technologies are more e ective and show more promise than the others, much work remains to be done to optimize these technologies so that they can be retrofitted or installed with minimal impact on the overall operation and e ectiveness of the treatment system.  相似文献   
953.
Ozone sensitivity analysis with the MM5-CMAQ modeling system for Shanghai   总被引:3,自引:0,他引:3  
Ozone has become one of the most important air pollution issues around the world. This article applied both O3/(NOy-NOx) and H2O2/HNO3 indicators to analyze the ozone sensitivity in urban and rural areas of Shanghai, with implementation of the MM5-CMAQ modeling system in July, 2007. The meteorological parameters were obtained by using the MM5 model. A regional emission inventory with spatial and temporal allocation based on the statistical data has been developed to provide input emission data to the MM5-CMAQ modeling system. Results showed that the ozone concentrations in Shanghai show clear regional differences. The ozone concentration in rural areas was much higher than that in the urban area. Two indicators showed that ozone was more sensitive to VOCs in urban areas, while it tended to be NOx sensitive in rural areas of Shanghai.  相似文献   
954.
The formation potential of four trihalomethanes (THMFP) and seven haloacetic acids (HAA7FP) in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution system (SDS) chlorination method. The specific ultraviolet absorbance (SUVA254: the ratio of UV254 to dissolved organic carbon (DOC)), which ranged between 0.9 and 5.0 L/(mg m), showed that the organic compounds in di erent source waters exhibited di erent reactivities with chlorine. The HAA7FP of source waters ranged from 20 to 448 g/L and the THMFP ranged from 29 to 259 g/L. The HAA7FP concentrations were higher than the THMFP concentrations in all but one of the samples. Therefore, the risks of haloacetic acids (HAAs) should be of concern in some source waters. TCM (chloroform) and BDCM (bromodichloromethane) were the major THM constituents, while TCAA (trichloroacetic acid) and DCAA (dichloroacetic acid) were the major HAA species. Br-THM (brominated THM species) were much higher than Br- HAA (brominated HAA species), and the formation of Br-DBP (Br-THM and Br-HAA) should be of concern when the bromide concentration is over 100 g/L.  相似文献   
955.
Night-time OH levels have been determined for UK urban surface environments using two methods, the decay and steady state approximation methods. Measurement data from the UK National Environmental Technology Centre archive for four urban sites (Bristol, Harwell, London Eltham and Edinburgh) over the time period of 1996 to 2000 have been used in this study. Three reactive alkenes, namely isoprene, 1,3-butadiene and trans-2-pentene were chosen for the calculation of OH levels by the decay method. Hourly measurements of NO, NO2, O3, CO and 20 VOCs were used to determine night-time OH level using the steady state approximation method. Our results showed that the night-time OH levels were in the range of 1 105–1 106 molecules/cm3 at these four urban sites in the UK. The application of a t-test of these analyses indicated that except Bristol, there was no significant di erence between the OH levels found from the decay and steady state approximation methods. Night-time levels of the OH radical appeared to peak in summer and spring time tracking the night-time O3 levels which also passed through a maximum at this time.  相似文献   
956.
Ozone sensitivity was investigated using CAMx simulations and photochemical indicator ratios at three sites (Pingtung City, Chao- Chou Town, and Kenting Town) in Pingtung County in southern Taiwan during 2003 and 2004. The CAMx simulations compared fairly well with the hourly concentrations of ozone. Simulation results also showed that Pingtung City was mainly a volatile organic compounds (VOC)-sensitive regime, while Chao-Chou Town was either a VOC-sensitive or a NOx-sensitive regime, depending on the seasons. Measurements of three photochemical indicators (H2O2, HNO3, and NOy) were conducted, and simulated three transition ranges of H2O2/HNO3 (0.5–0.8), O3/HNO3 (10.3–16.2) and O3/NOy (5.7–10.8) were adopted to assess the ozone sensitive regime at the three sites. The results indicated that the three transition ranges yield consistent results with CAMx simulations at most times at Pingtung City. However, both VOC-sensitive and NOx-sensitive regimes were important at the rural site Chao-Chou Town. Kenting Town, a touring site at the southern end of Taiwan, was predominated by a NOx-sensitive regime in four seasons.  相似文献   
957.
室内空气中挥发性有机污染物治理对策   总被引:1,自引:0,他引:1  
近年来,室内空气污染问题得到越来越多的重视,人们意识到维持良好室内空气环境的重要性,如何有效地治理室内空气污染成为了目前迫切关注的问题。文章对室内空气污染以及几种净化技术做了系统的综述,阐述了室内空气污染物的来源、危害,客观地评价了目前室内空气传统污染治理方法如通风换气、物理吸附法、化学吸收法、臭氧净化法,以及催化氧化法等空气净化技术的优缺点及空气净化技术的发展趋势,提出不同室内空气污染的分类,并针对不同的分类提出相应的方法,对污染治理进行指导。  相似文献   
958.
建立了一种用高效液相色谱法测定空气中的醛酮类化合物的方法.该方法用2,4-二硝基苯肼(DNPH)的磷酸溶液为吸收液,将醛酮类化合物转化为醛酮-DNPH衍生物,测定空气中的含量.方法的相关系数大于0.999,检出限为2~10 μg/m3,回收率大于85%.该方法灵敏度高,前处理简单,可用于环境空气中醛酮类的测定.  相似文献   
959.
气相色谱一质谱联用仪(GC-MS)因其准确、快速、高灵敏度等优点在环境监测中被广泛应用。文章介绍了GC-MS仪仪器类型,综述了其在水环境,大气环境,恶臭物质方面的应用研究。  相似文献   
960.
建立了吹扫捕集一气相色谱/质谱联用测定饮用水中59种挥发性有机物的方法,方法检出限为0.004~0.085μg/L,可满足饮用水中特定有机分析项目的检测要求。  相似文献   
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