| 英文摘要 |
The scope of work for this project includes: 1) Establishing and updating of the emission inventory; 2) Monitoring for the stationary emission and the ambient environment; 3) Revision, integration, and impact assessment of dioxin and heavy metal emission regulations; 4)Investigating the speciation changes and emission reduction strategies of mercury from coal-fired boilers.
The total dioxin emission quantity in Taiwan is estimated to be 25.33~172.22 g I-TEQ/year in 2011 with an average of 55.74 g I-TEQ/year. As for the heavy metal emissions in 2011, the total lead emission is 10.366 metric tons/year, cadmium emission is 0.830 metric tons/year, mercury emission is 1.454 metric tons/year, and arsenic emission is 3.745 metric tons/year. The changes are small over the years.
Monitoring of dioxin emissions were done in non-steel refineries, crematoriums, coal-fired boilers, and electric arc furnace (EAF) fly ash treatment plants. All five of the monitoring completed was within the emission limit. However, the emissions detected from crematoriums had larger variability; a better control and management strategy is recommended. DL-PCBs accounted for 7%~11% of total dioxin. However, the WHO2005-TEF of dioxins and furans are lower than I-TEF. As for the heavy metal emissions, mercury emissions from cement rotary kiln tend to be higher due to processing of sludge from industrial wastes. Emissions of manganese and zinc from electroplating industry were high due to the raw material used. Chromium(VI) accounts for 8.6%~13.4% of total chromium emission from electroplating industry. Boilers using lump coals emit higher concentration of heavy metals. However, the number of such boilers is small, so is the total emission.
This year the ambient dioxin monitoring is targeted on the general monitoring stations and monitoring stations around major pollution sources. 4 more monitoring stations were added around major pollution sources comparing to last year’s project. The average ambient dioxin concentration monitored from general monitoring stations is the lowest in the past three years. Among all the newly added monitoring stations, highest concentration of dioxins was detected near the Shuimei Incinerator. However, it is still below the standards of Japanese ambient air quality regulations.
The monitoring data of heavy metal in ambient air shows that in 2012 the yearly average of lead, cadmium, nickel and selenium is under the ambient air quality standards published by the European Union. The ambient mercury concentration is higher in Kaohsiung area due to the large number of major sources. Designing an emission reduction strategy for the area is recommended.
This year studies were done on the species changes of mercury in coal-fired boilers, which can be used as reference for the development of mercury emission standard from coal-fired boilers. The tests results showed that the mercury emissions were compliable to even the most stringent regulation in the world. The removal rate of existing control devices was higher than 80%, which exists mainly in the fly ash. The mercury emitted into the ambient air is mostly in the form of gaseous elemental mercury.
As for the revision of emission regulation, a draft is proposed to combine the emission regulations for waste incinerators and the steel industry. A draft of particulate emission standards of electric arc furnaces is also completed.
Currently, the dioxin emission standard for stationary pollution sources is in effect and the Bureau of the Environmental Inspection has carried out relevant inspection work. This study assists with the supervising of the sampling processes and reviewing of the reports. During the project period, 33 inspections were completed. In 2012, a total of 155 inspections were conducted by environmental protection units throughout the nation, which accounted for 23% of all major sources. A total of 10 inspections did not meet the emissions standards, inspection failure rate of 6%.
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