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Chen Y.,Peking University | Chen Y.,Capital University of Economics and Business | Luo B.,Sichuan Environmental Monitoring Center | Xie S.-D.,Peking University
Atmospheric Environment | Year: 2015

Chengdu is an inland megacity in the Sichuan Basin, where dust influence remained an open question. During a one-year haze campaign, two dust events were identified in March 2013, indicating that desert dust can be transported to Chengdu and impacted local air quality strongly. The suggested low SO2/PM10, NO2/PM10 and PM2.5/PM10 ratios of 0.15, 0.27 and 0.40 could be used as immediate indicators for dust days. On typical dust day of March 12, PM10 was as high as 359.1 μg m-3, and crustal matter contributed 80.5% to total PM2.5 mass (106.6 μg m-3). Enrichment factors of most elements have decreased due to the dilution effect except for Ca and Mg. The dust was mainly from western and northern dust regions in China, including the "Northerly Mongolia Path", "Western Desert Path" and "Northwestern Desert Path". Due to the obstruction of Qinghai-Tibet Plateau on the west, the dust air to Chengdu was mostly from the northeastward direction after passing over Qinling Mountain. Moreover, the air experienced obvious elevation from its source regions driven by the cold front synoptic pattern. The spatial distribution of high AOD (Aerosol Optical Depth) values over 1.2 but low Ångström exponent of 0.5-0.6 around Chengdu verified the coarse pollution patterns. However, the dust pollution was not serious in nearby Chongqing and Guizhou and exhibited weak regional feature, a result different from those in Beijing and Shanghai. © 2015 Elsevier Ltd.


Chen Y.,Peking University | Xie S.,Peking University | Luo B.,Sichuan Environmental Monitoring Center | Zhai C.,Chinese Research Academy of Environmental Sciences
Atmospheric Environment | Year: 2014

The Sichuan Basin is a low visibility area in southwest China, where the hilly and basin topography, plus humid and stagnant weather, lead to unique pollution patterns. To identify the characteristics and sources of carbonaceous aerosols, one-year record of 24-h PM2.5 samples were analyzed for organic carbon (OC) and elemental carbon (EC) content following the thermal/optical transmission protocol at three cities (Chengdu (CD), Neijiang (NJ), and Chongqing (CQ)) in the region during May 2012 to April 2013. The annual average concentrations were 19.0±13.3μgOCm-3 and 4.6±2.6μgECm-3 in CD, 18.3±8.4μgOCm-3 and 4.1±1.8μgECm-3 in NJ, and 15.2±8.4μgOCm-3 and 4.0±1.6μgECm-3 in CQ, respectively. Organic matter (1.6OC) plus EC contributed about 40% of PM2.5 mass and displayed weak regional uniformity. Relatively high ratios of OC to EC were observed in the region with 4.3 for CD, 4.6 for NJ, and 3.8 for CQ, respectively. OC and EC pollution in the region exhibited interesting season-dependent characteristics with the lowest concentrations and OC/EC ratios in summer, but higher levels in other seasons. Higher OC/EC ratios in spring and autumn resulted from biomass burning, and in winter were from the enhanced secondary organic aerosol formation under favorable conditions. The exceptionally high OC and EC levels in May and October, mostly notable in CD, resulted from the burning of agricultural residues during harvest period. The high K+ concentrations and the high Kexcess/EC ratios implied the persistent influence of biomass burning throughout the year. Using a novel technique combing the EC tracer method and potassium mass balance in the aerosols, a K/EC ratio of 1.22 was used to retrieve the OC from biomass burning and the estimated contributions were 30.8%, 28.3%, and 21.9% in CD, NJ, and CQ, respectively, while secondary OC contributions to OC were 26.7%, 24.6%, and 25.7% in CD, NJ, and CQ, respectively. © 2014 Elsevier Ltd.


Leng G.,Sichuan University | Feng L.,Sichuan University | Li S.-B.,Sichuan University | Qian S.,Sichuan Environmental Monitoring Center | Dan D.-Z.,Sichuan University
Environmental Forensics | Year: 2013

A simple and rapid method has been developed for the determination of total Hg in drainage sediment. The method is performed by using a sequential injection (SI) system with cold vapor generation atomic fluorescence spectrometry (CVAFS) after a closed microwave assisted digestion. Digestion was carried out at a temperature of 140°C for 5 minutes using a mixture of 10% HCl + 50% HNO3 +40% H2O as digestion acid media. Stability experiment revealed that the extracted samples were stable in 24 hours. The SI-CVAFS system was well optimized. At optimized conditions, the detection limit of the method was 0.5 ng/g-1. Relative standard deviation (RSD) for the complete procedure by the analysis of the 10 digestions was 3.7%. The method was validated against 3 drainage sediment certified reference materials: GSD-2, GSD-9, and GSD-10 and successfully applied to the determination of Hg in the sediment of Pi River, China. © 2013 Copyright Taylor and Francis Group, LLC.


PubMed | Low Carbon Technology, University of Sichuan, U.S. Center for Disease Control and Prevention and Sichuan Environmental Monitoring Center
Type: | Journal: The Science of the total environment | Year: 2016

The effect modification of meteorological factors on the association between ambient Sulphur dioxide (SO


PubMed | Low Carbon Technology, University of Sichuan, U.S. Center for Disease Control and Prevention, Sichuan Environmental Monitoring Center and Kunming Medical University
Type: | Journal: The Science of the total environment | Year: 2017

Attributable risk is an important indicator for planning and evaluating public health interventions. However, most current measures of the attributable risk of air pollutants have not considered temporal relationships between exposure and risk. More importantly, limited information is available regarding the attributable risk due to ambient air pollutants in basin regions like the Sichuan Basin, China. To quantify the association between PM


Zhang N.,Nanjing University | Du Y.,Nanjing University | Du Y.,Sichuan Environmental Monitoring Center | Miao S.,Institute of Urban Meteorology
Advances in Atmospheric Sciences | Year: 2016

A microscale air pollutant dispersion model system is developed for emergency response purposes. The model includes a diagnostic wind field model to simulate the wind field and a random-walk air pollutant dispersion model to simulate the pollutant concentration through consideration of the influence of urban buildings. Numerical experiments are designed to evaluate the model’s performance, using CEDVAL (Compilation of Experimental Data for Validation of Microscale Dispersion Models) wind tunnel experiment data, including wind fields and air pollutant dispersion around a single building. The results show that the wind model can reproduce the vortexes triggered by urban buildings and the dispersion model simulates the pollutant concentration around buildings well. Typically, the simulation errors come from the determination of the key zones around a building or building cluster. This model has the potential for multiple applications; for example, the prediction of air pollutant dispersion and the evaluation of environmental impacts in emergency situations; urban planning scenarios; and the assessment of microscale air quality in urban areas. © 2016, Chinese National Committee for International Association of Meteorology and Atmospheric Sciences, Institute of Atmospheric Physics, Science Press and Springer-Verlag Berlin Heidelberg.


Zeng Y.G.,Chengdu University of Technology | Li L.,Chengdu University of Technology | Zhao H.,Sichuan Environmental Monitoring Center
Advanced Materials Research | Year: 2014

The chemical oxygen demand and permanganate index in 2012 in jiuzhaigou water environment were discussed, and their mutual relations were researched. Theoretical references for the establishment of river water pollution prevention mechanisms were provided. The ratio of chemical oxygen demand and permanganate index is 2.71:1 and their linear regression equation is "y = 3.337× 0.7519". © (2014) Trans Tech Publications, Switzerland.


Luo B.,Sichuan Environmental Monitoring Center | Wan X.,Sichuan Environmental Monitoring Center | Deng X.,Sichuan Environmental Monitoring Center | Yu Y.,Sichuan Environmental Monitoring Center | Xie Z.,Sichuan Environmental Monitoring Center
Chinese Journal of Chromatography (Se Pu) | Year: 2016

A method was developed for the simultaneous determination of 18 phenol pollutants in waste water by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). A volume of 5.0 mL waste water was placed into a centrifuge tube. Ammonia was added to the waste water to adjust pH ≥ 12. A volume of 1.0 mL methylene chloride-hexane solution (2: 1, v/v) was added to the waste water, then the centrifuge tube was oscillated for 5 min and centrifuged for 5 min at 4000 r/min. The water sample was filtered through a 0.22 μ m polytetrafluoroethylene (PTFE) microfiltration membrane and adjusted to neutral by formic acid. With methanol-0.01 mol/L ammonium formate/formic acid aqueous solution (pH 4.0) as mobile phase, the separation was performed on a Thermo Hypersil ODS column (100 mm×2.1 mm, 5.0 μ m) in gradient elution. The flow rate was 0.2 mL/min. The column temperature was 30°. The samples were detected by multiple reaction monitoring (MRM) mode with negative electrospray ionization. The phenol pollutants were quantified by external standard method. The calibration curves of the phenol pollutants showed good linearities in a suitable range with correlation coefficients (r2) not less than 0.9991. The detection limits of phenol pollutants ranged from 0.10 μ g/L to 0.88 μ g/L. The relative standard deviations of phenol pollutants were 2.5%-9.9% (n=6). The average recoveries of the 18 phenol pollutants spiked in waste water samples ranged from 68.7% to 118%(n=3). The method has been proven to be sensitive, rapid and little interference. It is suitable for the determination of the 18 phenol pollutants simultaneously in environmental waste water.


Zhao Y.,Sichuan Environmental Monitoring Center | Yang P.,Sichuan Environmental Monitoring Center | Qian S.,Sichuan Environmental Monitoring Center
Chinese Journal of Chromatography (Se Pu) | Year: 2015

A new and fast method was developed for the simultaneous determination of 14 aniline derivatives (ADs) in water by direct injection-liquid chromatography-tandem mass spectrometry (LC-MS/MS) through optimizing chromatographic and mass spectrometric conditions. The water sample was filtered through a 0.45 μm polyether sulfone (PES) microfiltration membrane. The separation was performed on a Shim-pack FC-ODS column (75 mm×4.6 mm, 3 μm) with methanol-0.1% (v/v) formic acid aqueous solution (35:65, v/v) as mobile phases in gradient elution mode. The flow rate was 0.3 mL/min, and the column temperature was 35 °C. The analytes were detected by LC-MS/MS in multiple reaction monitoring mode. Under the optimized conditions, the analysis of the 14 aniline derivatives was completed within 12 min and the calibration curves showed good linearity with correlation coefficients not less than 0.999. The detection limits of the 14 aniline derivatives ranged from 0.03 μg/L to 4.19 μg/L. The relative standard deviations of the 14 aniline derivatives in the spiked surface water at three levels (0.5, 5.0, 20.0 μg/L) were 0.4%-9.4% (n = 6). The proposed method has the advantages of good anti-interference ability, rapidness and high sensitivity. It was successfully applied to the analysis of real samples, and the recoveries of the 14 aniline derivatives in the spiked real samples were 68.0%-130%.


Zhao Y.,Sichuan Environmental Monitoring Center | Xie Z.,Sichuan Environmental Monitoring Center | Pan L.,Sichuan Environmental Monitoring Center | Yao H.,Sichuan Environmental Monitoring Center
Chinese Journal of Chromatography (Se Pu) | Year: 2016

A method was developed for the determination of 18 aniline derivatives (ADs) in water by liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with solid phase extraction. The water sample was enriched by a mixed cation exchange column (MCX) and a silicon substrate cation exchange column (SCX). The column was eluted by ammonia methanol solution. The eluent was concentrated and then diluted with purified water to the appropriate multiple. The separation of ADs was performed on an ODS column, and the mobile phase of methanol-0.005% (v/v) formic acid aqueous solution was employed with gradient elution, then the analytes were detected by LC-MS/MS in multiple reaction monitoring mode, with internal standard method for quantitative analysis. The analysis of the 18 ADs was completed in 15 min and the calibration curves showed good linearity. When an MCX was employed for extraction, the method detection limits of the 16 ADs ranged from 0.002 to 0.035 μ g/L, the average recoveries and relative standard deviations of the 16 ADs in surface water were 72.5%-92.5% (n=6) and 1.4%-9.6% (n=6), respectively. When an SCX was employed for extraction, the method detection limits of the 17 ADs ranged from 0.013 to 0.207 μ g/L, and the average recoveries and relative standard deviations of the 17 ADs in surface water were 66.5%-102% (n=6) and 2.4%-13.6% (n=6), respectively. During the development of this method, five elimination methods of matrix interference were studied. The results showed that adjustment of chromatographic separation conditions is the most efficient method, and the selection of appropriate method for sample preparation is the second one. The replacement of ion source, internal standard method and calibration by matrix matched standard solution can eliminate and compensate matrix interference to some extent.

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