This year project implementation period from November 24, 2018 to November 23, 2019, completed 2 times discharge pipes flue gas, 6 times agricultural waste combustion, 4 times gold paper combustion and 2 times diesel vehicle PM2.5 sampling and chemical composition analysis, to establish the source profile , PM2.5 emission estimation and comparison with TEDS data, optimization of Air quality forecasting/Pollution analysis system to improve accuracy and pollution source tracking ability, PM2.5 pollution source analysis in different Meteorological Parameters ,and control strategy benefit assessment. And the completion of the 60-day radio broadcast and 4 internal meetings. The overall progress towards rate is 100%.
PM2.5 emissions from coal-fired boiler are the highest in sulfate (SO42-) and carbon(EC,OC). The metal elements are mainly crustal elements such as Al, Fe, Ca, Na, Mg, and K, and Ba is a characteristic element of coal fired boiler. Because the PM2.5 species distribution is consistent with the sampling results in 2016, and this year results is obtained by increasing the number of samples to effectively master process variability and emission characteristics,it is confirmed that the PM2.5 source profile database established of coal-fired boiler at Yunlin County in this study has been quite representative.
The filterable PM2.5 emission coefficient of coal-fired boiler (C1 and C2) is 104 g/ton and 20.1 g/ton,and the condensable PM2.5 emission coefficients is 31.4 g/ton and 21.9 g/ton, respectively, which are lower than the same coal-fired boiler pipeline sampling in 2016 study. C1 due to the increase in the number of samples to improve the representativeness,and the emission coefficient is similar to that of the large coal-fired boilers in the Mailiao industrial zones, and more representative than the sampling results in 2016. C2 concludes that the media gas-gas heater(MGGH) has been added, which can improve the PM2.5 removal efficiency compare when this equipment is not installed.
The Camphor and Madagascar Almond agricultural waste burning PM2.5 sampling results showed PM2.5 emission coefficient are about 1,000~2,600 mg/kg-AW, and Casuarina is about 2,000~2,200 mg/Kg-AW. The major chemical composition is carbon. Among them, there are more elemental carbon(EC) in Camphor and Madagascar Almond, and there are more organic carbon(OC) in Casuarina. The ion characteristics of the three species are mainly chloride ion(Cl-) and potassium ion(K+), but Casuarina was Cl-, sodium ion(Na+) is much higher than K+, which is the characteristic species for burning of agricultural waste on the seaside street trees.
The PM2.5 emission coefficient of gold paper burning is about 1,400~1,650 mg/kg-AW. The source profile of PM2.5 burning of two types of gold paper are mainly characterized by elemental carbon(EC). The ionic characteristics are relatively rich in sulfate(SO42-), sodium ion(Na+), chloride ion(Cl-), sodium(Na) and potassium (K), which are the major species for gold paper burning.
Almost all particulates emitted by diesel vehicles are PM2.5. Among them, EC, OC and Na are the characteristic elements of PM2.5 for diesel vehicles. The diesel trucks which added the Diesel Particulate Filter(DPF),the filterable PM2.5 emission coefficient between DPF is 0.19 g/km and 0.01 g/km, the condensation PM2.5 emission coefficient between DPF is 0.498 g/km and 0.509 g/km. Shows that installing a DPF can effectively improve filterable PM2.5 removal, but has no effect on condensable PM2.5.
Estimated PM2.5 emissions from pollution sources in Yunlin County. A total of 19 pipelines of the large-scale coal-fired boilers have a total filterable FPM2.5 emissions of about 721 T/yr. The total PM2.5 emissions (including condensable PM2.5) total about 1,118 T/yr, which is 2.1 times and 3.3 times higher than TEDS10 database, indicating that TEDS may underestimate PM2.5 emissions from coal-fired boilers. In addition, the PM2.5/PM10 coefficient of the dust of the sampling results, and it is found that TEDS may underestimate the PM2.5 in the PM10 emitted by river dust, especially the PM2.5 emission potential of the dust at the estuary, and the characteristics of the PM2.5 emissions from sea line township streets dust which is higher than the mountain line townships dust. It can be used as a reference for the localization coefficient adjustment of the new TEDS in the future for EPA.
The accuracy of the event day forecast (accurate forecast days/total days) is more than 83%. which means that it can accurately predict domestic and foreign pollution events occurred. This year's forecast system updated the emissions database to TEDS10, and revised the land use pattern, and the statistical indicators of all air quality areas have improved. The pollution source analysis system adds the detected PM2.5 aerosol profile data as a conversion coefficient to optimize the performance of the photochemical module of the model. It also integrates the display web platform, and provides daily spatial distribution maps of PM2.5 forecasts in GTx and CMAQ modes, as well as the observation results of the EPA, and the proportion of pollution sources(factory, traffic, area sources). Provide EPA as a reference for early warning and emergency decision-making before the deterioration of the air quality deteriorates.
Analyze the source of PM2.5 in Yunlin, At Douliu and Lunbei mainly comes from National Road No. 1(diesel truck), large central pollution source (Taichung Power Plant), and adjacent industrial areas; The PM2.5 at Mailiao and Taixi mainly come from Mailiao Industrial Zone, ships and diesel vehicles. Simulate various pollution reduction measures (factory, traffic, area sources) of Yunlin County, EPA and Public enterprise. If implemented as scheduled, the annual average reduction of PM2.5 in Douliu, Lunbei, Taixi and Mailiao can reach 8.16, 4.12, 3.44, and 3.07μg/m3, of which the control of mobile sources (diesel vehicle replacement) and port area emissions have the most significant effect on improving PM2.5 in Yunlin. And control Mailiao Industrial also has a contributed on Chiayi and Tainan city PM2.5 improvement.