In recent years, environmental pollution issues related to the (fugitive) emissions from factories have gained a great deal of attentions from the general public, as people are aware of the potential adverse health effect that might affect their quality of life. With the increasing susceptibility of respiratory illnesses, such as children’s asthma or upper respiratory trait diseases, the figures of environmental nuisance complaints has been increasing at an unprecedented rate in recent years. The emission of volatile organic compounds (VOCs) not only contributes to the formation of ground level ozone and various air contaminants, but also triggers a variety of health problems, including respiratory illness, circulation diseases, or even malignant tumors. For these reasons, Taiwan Environmental Protection Administration (TEPA) has applied several air pollution control strategies, such as permit system, emission standards, fugitive emission control, and economic incentives, on stationary sources to reduce VOCs emission and improve air quality.
The result of this project is for supporting the investigation of the continuous complaints received by the county and city authorities regarding the major odor incident. According to the investigation on the odorous pollutant in the campus of the Shulin Elementary School in the Guanyin Industrial Park and the sources of pollutions, the "sour and stinky smell" in the campus mainly came from the terephthalic acid plant (PTA) which was carried by the west south-west wind. The source of acetic acid is suspected to be contributed from the recovery of process water, while the front of the air pollution prevention facility for the para-xylene oxidation reaction process contained significant amount of methyl bromide, acetic acid, and n-propyl acetate (the exhaust gas of mother liquor recovery system). The existing air pollution prevention facility in the plant cannot effectively remove odorous pollutants and harmful substances in exhaust gas. According to the investigation of odorous pollutants and their sources for the Central Police University, the major odorous pollutants originated from toluene and dimethylformamide, which are the organic solvents used in the PU synthetic leather manufacturing process, located in the north and north-west of the University. According to the results of the field survey, the pollution was caused by the improper design, operation and maintenance of the air pollution prevention facility in the plant. As for the odor pollution problem near the Yilan Loung Te Industrial Park, after the plants in the Industrial Park improved their air pollution prevention facilities for the PTA process, the sour smell around the area has decreased significantly. However, the odor of sulfur (carbonyl sulfur) and carbon disulfide produced by the Rayon process has replaced the odor of methyl acetate in the PTA process, becoming the major odor complained by the local residents. According to the result of investigation performed in this project, the existing activated carbon adsorption/desorption equipment in the plant can recover more than 99% of carbon disulfide. However, in the process of treating carbon disulfide, the existing air pollution prevention facility caused hydrolysis of the carbon disulfide, producing carbonyl sulfur, while the carbonyl sulfur treatment efficiency of the adsorption/desorption equipment was low, causing most of the carbonyl sulfur to be discharged into the atmosphere and resulting in the odorous pollution at the downwind.
With regards to volume reduction and pollution improvement, for the PTA plant which contributed the major odor in the campus of the Shulin Elementary School in the Guanyin Industrial Park, this project has invited the Environmental Protection Administration and the Department of Environmental Protection, Taoyuan to visit the PTA plant and explain the investigation results, which suggested that the major odorous pollutants were related to the "water" used in the manufacturing process. The plant further analyzed the VOCs composition and concentrations in the process water to confirm the scope of the impact and use them as the reference to come up with subsequent improvement strategies. As for the exhaust gas treatment equipment for the production of terephthalic acid via the para-xylene oxidation reaction, we will discuss the applicability and the optimization of equipment for the air pollution prevention facility for the PTA process through subsequent integration discussion meetings of other terephthalic acid processes, which will serve as the reference for subsequent improvement. In the investigation of the composition of the petrochemical process combustion equipment exhaust gas, 10 discharge pipes of the incineration equipment in the Mailiao Process Area on the north side of the Sixth Naphtha Cracker Industrial Park were selected to carry out the measurement this year. Among the plants measured, only the combustion by-products generated by the resource recycling plant is related to the sour smell. Due to the wide range of wastes received by the recycling plant, it is difficult to control its combustion temperature. Moreover, due to the nitrogen or sulfur-containing waste as well as the moisture of the waste, the combustion temperature was reduced, which produced various odorous and harmful air pollutants. With regards to the measurement results of the discharge pipes of the thermal incineration equipment in the Mailiao Process Area on the north side of the Sixth Naphtha Cracker Industrial Park, this project also visited various plants to explain about the measurement results. During the visit, the resource recycling plant promised to increase the combustion temperature of its fluidized bed incinerator, reducing the generation of acidic by-products due to incomplete combustion at low temperature. Other processing plants also agreed to further review the combustion temperature settings of their incineration equipment, and pay more attention to the types of waste or fuel used for incineration, reducing the chances of generating combustion by-products with unpleasant smell. As for the training of techniques for investigating unknown air pollutants, a total of 5 technical transfer training classes were organized this year, with a total of 277 participants.
In the investigation of VOCs (volatile organic compounds) emission for domestic surface coating industry, a summary of the VOCs emissions based on the air pollution charges for the domestic surface coating related processes in the past 3 years was completed. Currently, there is no industry-related regulation and the top three VOCs emissions are "metal surface coating procedures (19.2%)", "gravure printing operation procedures (13.0%)" and "plastic product coating procedures (11.0%)". In addition, the background surveys of 42 companies in three surface coating-related businesses was completed; 14 companies in each of the following three businesses, namely gravure printing operations, metal surface coating operations, and plastic product surface coating operations. With regards to gas colleting facility, there are 10, 11 and 11 enclosed air hoods (plastic curtains) or closed compartments (gas collecting efficiency 80 ~ 90%) for gravure printing operations, metal coating operations and plastic product coating operations, respectively. In terms of pollution prevention facility, there are 10, 6 and 2 companies in gravure printing operations, metal surface coating operations and plastic product surface coating operations, respectively that use incineration equipment (zeolite concentrating rotor + regenerative thermal oxidizer, exhaust gas incinerator, catalytic incinerator, etc.), and the rest use scrubbers or activated carbon adsorption equipment. For the 42 companies in the three surface coating-related businesses, in responding to the establishment the industry-specific regulations in the future and based on the estimated results of VOCs reduction benefits in each surface coating business, the 14 gravure printing companies can reduce 154.19 metric tons of VOCs per year; the 14 metal surface coating companies can reduce 86.10 metric tons of VOCs per year; and the 14 plastic product surface coating companies can reduce 228.87 metric tons of VOCs per year. In addition, the compilation of the "Guidebook for VOCs Reduction and Improvement for Metal Surface Coating Processes and Tape Manufacturing Industry" was completed. The contents of the Guidebook include (1) industry overview, (2) manufacturing process and VOCs exhaust gas emission characteristics, (3) process gas collection/emission improvement, and (4) VOCs reduction improvement, serving as the reference for surface coating related businesses in reducing VOCs emission.
For the investigation on VOCs emission characteristics of general wastewater (sewage) treatment plants in industrial parks, the background investigation of 10 general wastewater treatment plants in industrial parks was completed. The only general wastewater treatment plant which still exhibits the unpleasant odor is the one in Changhua Coastal Park (Lugang District). The odor is mainly the smell of electroplating wastewater. In terms of the intensity of the odor, the odor is considered a mild odor (wastewater + sludge smell). As for the neighboring residents, there are 7 general wastewater treatment plants in industrial parks which have residents nearby, while the other 3 general wastewater treatment plants have no residents in the immediate vicinity. Furthermore, according to the summary of the wastewater VOCs concentration and wastewater surface VOCs concentration for the the influent water units, the aeration tank units, and the sludge treatment units in the 10 general wastewater water treatment plants in industrial parks, the VOCs concentration in influent water was 0.004 ~ <1.050 mg / L and that above the water surface was 0.47 ~ 7.37 ppm; the VOCs concentration in the wastewater of the aeration tank was 0 ~ <0.658 mg / L and that above the wastewater surface was 0.02 ~ 6.03 ppm; and the VOCs concentration in the wastewater of the sludge treatment unit was 0 ~ <0.630 mg / L and that above the wastewater surface was 0.01 ~ 0.82 ppm. This suggests that the influent water unit and the aeration tank unit still have relatively high concentration of VOCs. In addition, based on the survey and related testing results, the amendment to Chapter 7 of the Wastewater Treatment Facility Regulations in the "Volatile Organic Compounds Air Pollution Control and Discharge Standards" was proposed.
In the process of developing emergency response measures for air pollution emergencies in public and private places, this project assists in proposing the “Emergency Response Measures and Warning Notification Operations for Air Pollution Incidents (Draft)”, which contain a total of 11 articles. The preliminary notice of the draft was completed on May 28, 2019. The project also assisted in conducting one seminar and one public hearing, summarizing the suggestions and recommendations from the industry, government, and academia for amending the Draft. It was officially announced on September 9, 2019 for implementation. In the feasibility assessment for establishing disaster prevention public warning system (cell broadcast), the information related to disaster prevention public warning system and other disaster prevention warning methods in the "Disaster Prevention Information Service Platform" of the National Fire Agency of the Ministry of the Interior have been compiled. Moreover, the scope, media characteristics, media restrictions, message publishers and the targets to be operated on for the two functions mentioned above were evaluated. This project recommends the use of cable TV and radio in the platform to issue air quality deterioration warning messages. In terms of the seminars and trainings, a total of 259 people participated in the two seminars for the "Air Pollution Emergency Measures and Air Pollution Monitoring Equipment Introduction" (one in Taipei and one in Kaohsiung). In addition, 71 people participated in the three training sessions for the "Disaster Prevention ＆ Rescue Information Service Platform Operation Training and ALOHA Simulation ＆ Analysis Operation " (one in Taipei, one in Taichung, and one in Kaohsiung).
