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Objective To investigate the water quality of finished water of the centralized water supply system in Shenzhen according to 106 indexes of water quality standards of China.Methods The collection and preservation of water samples was according to the standard examination methods for drinking water-collection and preservation of water samples (GB/T 5750.2-2006).The sanitary quality of the finished water samples collected from 35 centralized water supply systems in cities were determined and evaluated according to the Standards for Drinking Water Quality (GB 5749-2006) in May of 2008.Results The average qualified rate of drinking water was 82.9% (29/35) in Shenzhen.Among 106 indexes,4 indexes (such as turbidity,aluminum,manganese and free chlorine residue) exceeded the standard limits in degrees in some centralized water supply system.Conclusion According to the results of the present paper,it is considered that the water quality of the product water from the centralized water supply system in Shenzhen is good.
RESUMO
Objective To analyze time-space variation of air pollutants(SO2,NO2,PM10) and the correlation among them in inner region and outer region of Shenzhen from 2002 to 2007.Methods The daily concentration means of SO2,NO2 and PM10 during 2002 to 2007 from the nine environmental monitoring sites in Shenzhen were collected.The determination was conducted according to the Ambient Air Quality Criteria.Results From January to December,variation of air concentration of SO2,NO2 and PM10 met the "V" shape in inner region and outer region of Shenzhen in 2002-2007,which was descending from January to June and ascending from June to December.The level of the air pollutants in inner region and outer region was higher in fall and lower in summer.The air pollution level of the inner region was increasing from 2002 to 2004,then decreased in 2005,but increased again in 2006 and 2007.The tendency of the outer region was similar with the tendency of the inner region from 2002 to 2006,but the level of pollutants decreased in 2007.The air concentration of SO2 in outer region was higher than that in inner region in 2002-2007.The air concentration of NO2 and PM10 in outer region was higher than that in inner region in 2002 to 2006,but lower in 2007.The air concentration of SO2 in inner region and outer region in 2002-2007 was under the limit of grade 2 according to the GB 3095-1996,near to grade 1 in inner region.The air concentration of NO2 and PM10 was under the limit of grade 3 and grade 2 respectively.There was a close correlation among the levels of SO2,NO2,PM10 in Shenzhen.Conclusion The air quality in Shenzhen is better in China.The time-space variation of the air pollutants is obvious and a close correlation exists among the air pollutants.
RESUMO
Objective To explore the effects of the meteorologic factors on air pollutants and to establish a model of relationship between the meteorologic factors and concentration of air pollutants. Method The data of SO2,NO2 and PM10 concentration in the air and the related meteorologic factors (daily average,maximum and minimum atmospheric pressure and daily atmospheric pressure difference,daily average,maximum and minimum air temperature,monthly rainfall,daily average and minimum relative humidity and wind speed) from January 2002 to December 2007 were collected. The correlation between the air pollutant levels and related meteorologic factors was analyzed by the multiple regression models with SPSS 11.5 software and multiple regression equations were established. Results Minimum relative humidity was negatively correlated with the concentration of SO2 and NO2 in atmosphere . Daily minimum air temperature was negatively correlated with the concentration of NO2 in atmosphere. Daily average relative humidity and wind speed were negatively correlated with the concentration of PM10 in atmosphere. Daily atmospheric pressure difference was positively correlated with the concentration of PM10 in atmosphere. Multiple regression equations of the concentration of SO2,NO2 and PM10 in atmosphere and meteorologic factors have statistical significances. Conclusion The meteorologic factors have some effects on the air pollution levels. By using the correlation of meteorologic factors and the concentration of air pollutions,multiple regression equations can be established.