[Capacity Simulation Method Based on Regional Transfer Matrix and PM2.5 Concentration Target Constraint].

Atmospheric environmental capacity is an important reference in environmental planning. To meet the PM2.5 standard, a new method is proposed to balance the capacity among cities of Guangdong, with screening of the most unfavorable meteorological year and combining it with the regional transportation calculated by the CAMx-PSAT module. Pollutant overloading and capacity scenarios were also calculated. The results showed that, under the constraints of the cities' annual PM2.5 ≤ 35 µg·m-3, the capacities of SO2, NOx, NH3, and PM2.5 in Guangdong were about 6.8×105 tons, 1.35×106 tons, 4.6×105 tons, and 5.1×105 tons, respectively. Based on the benchmark scenario, SO2 emissions in Guangdong were overloaded by 10%, and the emissions of NOx, NH3, and PM2.5 exceeded by 12%, 9%, and 20%, respectively, compared to those of the capacity scenario. Ranked by the number of overloaded species in Guangdong, the cities of Guangzhou, Foshan, Zhongshan, and Qingyuan were on top. When achieving the capacity scenario, the annual PM2.5 concentration in Guangdong was about 30 µg·m-3, which meets the national secondary ambient air quality standard.

[Emission factors and PM chemical composition study of biomass burning in the Yangtze River Delta region].

The emission characteristics of five typical crops, including wheat straw, rice straw, oil rape straw, soybean straw and fuel wood, were investigated to explore the gas and particulates emission of typical biomass burning in Yangzi-River-Delta area. The straws were tested both by burning in stove and by burning in the farm with a self-developed measurement system as open burning sources. Both gas and fine particle pollutants were measured in this study as well as the chemical composition of fine particles. The results showed that the average emission factors of CO, NO, and PM2,5 in open farm burning were 28.7 g.kg -1, 1.2 g.kg-1 and 2.65 g kg-1 , respectively. Due to insufficient burning in the low oxygen level environment, the emission factors of stove burning were higher than those of open farm burning, which were 81.9 g kg-1, 2. 1 g.kg -1 and 8.5 gkg -1 , respectively. Oil rape straw had the highest emission factors in all tested straws samples. Carbonaceous matter, including organic carbon(OC) and element carbon(EC) , was the foremost component of PM2, 5from biomass burning. The average mass fractions of OC and EC were (38.92 +/- 13.93)% and (5.66 +/-1.54)% by open farm burning and (26.37 +/- 10. 14)% and (18.97 +/- 10.76)% by stove burning. Water soluble ions such as Cl-and K+ had a large contribution. The average mass fractions of CI- and K+ were (13.27 +/-6. 82)% and (12.41 +/- 3.02)% by open farm burning, and were (16.25 +/- 9.34)% and (13.62 +/- 7.91)% by stove burning. The K +/OC values of particles from wheat straw, rice straw, oil rape straw and soybean straw by open farm burning were 0. 30, 0. 52, 0. 49 and 0. 15, respectively, which can be used to evaluate the influence on the regional air quality in YRD area from biomass burning and provide direct evidence for source apportionment.

[Characteristics of particulate matters and its chemical compositions during the dust episodes in Shanghai in spring, 2011].

A continuous air quality observation was conducted in the urban area of Shanghai from April 28 to May 18 in 2011. The mass concentration of particle matters and main chemical compositions of fine particle were measured and analyzed. The mass concentrations of PM10 and PM2.5 during the dust episode were much higher than those in non-dust episode, with the maximum daily mass concentrations of PM10 and PM2.5 reaching 787.2 microg.gm-3 and 139.5 microgm(-3) , respectively. The average PM2.5 /PM10 ratio was (32.9 +/-14. 6)% (15. 6% -85.1% ). The total water soluble inorganic ions(TWSII ) contributed (27.2 +/- 19. 2)% (4. 8% -80. 8% ) of total PM2.5, and the secondary water soluble ions (SNA) , including SO(2-)4 , NO-(3) and NH(+)(4) , were (76.9 +/- 13.9)% (41.9%-94.2%) in TWSIl. The concentrations of TWSII and SNA in PM2.5 during dust days became lower than those in non-dust days while the trend of the ratio of Ca2+ to PM2.5, increased. The mean OC/EC value in non-dust days was higher than that in the heavy dust pollution episode, but lower than that in weak dust days. In addition, mineral-rich particle in dust period had an acid-buffer effect, making particle alkaline in dust days stronger. In non-dust days, SO(2-)(4) and NO(-)(3) mainly existed in the form of NH4HSO4, (NH4)SO4, and NH4NO3, and combined with other mineral ions during dust days.