In water quality measuring methods using ultraviolet spectrum absorption, optical signal detecting techniques are very important. The time-sharing sampling system is adopted to detect background light, reference light and measuring light with one dectector in double light, which can eliminate influences from the drift of source and background. The double wavelength band detection model can decrease the influence of turbidity in water. The techniques make the system more precise and reliable. The standard deviation is less than 1% and the maximum relative error is less than 2% for measurement of standard solutions. The results indicate that the precision and accuracy of the apparatus are good.

he typical atmosphere optical characteristics of Beijing Olympic Games were measured and analyzed with Raman lidar from Aug. 7th to Aug. 25th in 2008. The vertical profile and spatio-temporal distribution of aerosol extinction coefficient, backscatter signal and the ratio of extinction at different wavelength were shown, and the ratio of aerosol extinction and backscattering, optical depth and Angstrom exponent were calculated respectively. The variability of aerosol optical characteristics and the possible cause of formation were analyzed in combination with the ground level monitoring data. The results show that the heavy air pollution from Aug. 8th to 9th in 2008 is mainly caused by biggish size particles, the aerosol optical depth increases with small size contaminant accumulation after rain, and the Raman lidar is a flexible tool for atmosphere optical characteristics measurement.

The concentrations and the variation characteristics of the main pollutants including SO2, NO2, O3 and PM10 during Beijing Olympic Games were investigated based on data collected during the period from June 20th to September 22nd, 2008, at four locations in Beijing: Institute of Remote Sensing Applications, Yungang Town, Yanshan Petrochemical and Capital Airport. PM[EQUATION] is reported to be the major pollutant. The analysis shows a significant higher level of PM[EQUATION] in urban site than in rural. A ratio difference of 50% for PM[EQUATION] between rural and urban site in the first period (from July 1st to 19th and from July 20th to August 24th) was observed, which decreased to about 25% during the second period (from August 8th to 24th and from September 6th to 17th). The difference on diurnal variation of PM[EQUATION] mainly appeared during 01:00[EQUATION]11:00. The concentrations of primary pollutant SO[EQUATION] and NO[EQUATION] were below the Grade-II standards. With the implementation of mitigation measures, a decrease of the above two pollutants exceeded 14%. The results also showed that diurnal variation of NO[EQUATION] had a very clear cycle with two peaks in most stations, but only the case for SO[EQUATION] in Yanshan Petrochemical and Yungang Town stations. As the indicator of photochemical smog O[EQUATION] exhibited an obvious diurnal variation with high levels during daytime and low levels in nighttime. Two peaks of O[EQUATION] diurnal variation during daytime were observed in Yanshan Petrochemical and Yungang Town stations. Based on the statistical data the levels of O[EQUATION] increased at the early stage of reduction of pollutant emissions (before July 20th) and then continuous declined. The ratios of the maximum to minimum for O[EQUATION] showed a downward trend after June by analyzing the different diurnal patterns. Each pollutant of the above revealed a remarkable drop during the period from August 8th to 24th, 2008. Comparing the statistical data obtained from July 1st to 19th, with those obtained from July 20th to August 24th in 2008, SO[EQUATION], NO[EQUATION], O[EQUATION] and PM[EQUATION] decreases by 14%[EQUATION]33%, 15%[EQUATION]61%, 2.5%[EQUATION]14% and 10%[EQUATION]12% respectively.

Mobile passive differential optical absorption spectroscopy (DOAS) was used for the remote sensing of the emission flux of SO2 and NO2from area of a steel company during Beijing Olympic Games. The mean values of SO2and NO2flux were 4.1 ton/h and 1.0 ton/h derived from the observation results. The comparison of mobile passive DOAS results with MAX-DOAS observations shows a preferable identity and suggests that the results are reasonable and reliable. A further analysis revealed that the emission flux of these two gaseous pollutants decreased about 44% and 78% respectively. These results indicated that emission reduction had a remarkable effect.

The tropospheric nitrogen dioxide over the Olympic venues in Beijing was measured by ground-based multi axis differential optical absorption spectroscopy (MAX-DOAS) during the Olympic Games in 2008, and was compared with the result of OMI. It showed that the result of MAX-DOAS was higher than that of OMI, the maximum is 2.4 times the result of OMI; both instruments had good accordance([EQUATION]=0.64) when it’s clear, and when it was rainy or cloudy there was more different between the results of both instruments for the existing of cloud, with a correlation coefficient of 0.19, but the result of MAX-DOAS had better accordance with LP-DOAS, with a correlation coefficient of 0.92.

NH is the most abundant alkaline trace gas in the atmosphere which plays an important role in acid deposition and aerosol formation. The NH on-line monitoring system based on tunable diode laser absorption spectroscopy and long open path technology was used to continuously measure atmospheric NH concentration at an urban site near Beijing National Stadium during Beijing Olympic Games. The monitoring results show that the atmospheric NH concentration variation has an obvious diurnal periodicity, the rule is the concentration decreased in the daytime, and increased to the maximum at night. Moreover, the NH peak concentration decreased at the beginning of Beijing Olympic Games. The results reveal the positive effects of auto restriction for reducing NHconcentration and restricting aerosol formation.

Suspending particles in atmosphere is the important indicator to evaluate the environmental quality. Its spatial and temporal distribution can be obtained by means of lidar. The mass concentration and extinction of particles have a very good correlation. To estimate the vertical distribution of PM[EQUATION] (particulate matter with diameter less than or equal to 10 micrometer), the empirical relationship is established between the extinction and the mass concentration of PM[EQUATION] measured by TEOM in near ground layer. Combined with wind velocity in different heights which are measured by wind radar, particles transport flux to urban areas is calculated and the total amount of particles transport is estimated. The long-term continuous monitoring of important industrial source in Beijing is carried out, and the results are presented.

At present, the regional air pollution and atmospheric pollution transport are focal points of research. Beijing 2008 Olympic Games give a good chance to carry out researches on air pollution and mutual impacts between Beijing and neighboring regions. A new method for particulate matter transport flux is proposed using lidar and wind profile radar. This method can be used in the monitoring of particulate mass regional transport between city clusters. The structure and technical parameters of the dual-wavelength three-channel lidar are presented, and the atmospheric particulate matter mass concentration vertical distribution and particulate matter transport flux are discussed by combining with the data of wind profile. At last, the transport flux and transport amount of the particulate matter during typical duration are estimated, which are compared with the SO[EQUATION] concentration.

An open path Fourier transform infrared spectroscopy system which measured the ambient concentrations of multi-gas in Yanshan area of Beijing during 2008 Beijing Olympic Games is presented. The quantitative analysis model used for the determination of the concentration of the unknown species is described. The measured results show that, most of the gases were decreased during the traffic controlling ([EQUATION]29%) and the period of Olympic Games ([EQUATION]34%). With the influence of background concentration, C[EQUATION]H[EQUATION] increased of 6.09% and 19.66% during the traffic controlling and the period of Olympic Games. However, the typical diurnal variation shows the emission of C[EQUATION]H[EQUATION] was reduced significantly.

In urban areas, volatile organic compounds are important ambient pollutants because of their detrimental effects on human health and their role in the chemistry of atmosphere as precursors of ozone and other oxidants. The concentration of C[EQUATION]H[EQUATION] was analyzed by Fourier transform infrared spectroscopy. The variation of the long-time trends of the C[EQUATION]H[EQUATION] concentrations in Beijing may be ascribed to the emission changes from the plane and the motor vehicle. During Beijing Olympic Games, the C[EQUATION]H[EQUATION] concentrations in Beijing Capital Airport may be ascribed to the emission changes of planes, and the C[EQUATION]H[EQUATION] concentrations have good relativity with the quantity of planes.

The software design for MAX-DOAS monitoring system is introduced, which is used to control spectrometer and detector unit, telescope direction, and temperature control unit. The control software, compiled by Microsoft Visual Basic 6.0, is convenient with compendious interface and simple operation. The system can work continuously and unattendedly in a long time.