This Project commenced on 20/11/2017. Project scopes include
•consolidated and analyzed data of hazardous air pollutants;
•consolidated and analyzed emission information of hazardous air pollutants from stationary sources in the county;
•evaluated priorities on regulating target stationary sources;
•continuous emission monitoring of VOCs; and
•tested hazardous air pollutants
Project results during the reporting period are summarized below.
(1)To better understanding HAP species concentrations in special industrial stations, this Project had consolidated and analyzed monitoring information in Liuhing Industrial District from 2015 to 2017. Seven important pollutants, namely Benzene, Ethylbenzene, Arsenic, Formaldehyde, Nickel, Lead and Acetaldehyde were picked. Formaldehyde had the highest yearly average concentration (20.5~54.1 ppbv) among all pollutants, indicating formaldehyde was commonly found in atmosphere. Lead was among heavy metals that had the highest yearly average concentration (0.010~0.016 μg/m3), but it was below overseas baseline concentration (0.5 μg/m3). Having taken into consideration the hazardous nature of all pollutants, formaldehyde, acetaldehyde and benzene had higher risk of carcinogenicity whereas acetaldehyde imposed the greatest non-cancer-causing risks on health.
(2)4-season monitoring of hazardous air pollutants targeting VOCs, carbonyl compounds, acidic gases and PAHs had been completed. 16 samples were collected, and 5 types of VOCs were tested with methanol having the highest concentration (23.9 ppbv), followed by 2-Butanone (5.1 ppbv), Acetone (4.5 ppbv) and Toluene (2.9 ppbv). 3 types of carbonyl compounds were tested with formaldehyde having the highest concentration (0.0275 ppmv), followed by acetaldehyde (0.0217 ppmv), but occurrences were not frequent. Test results of 7 types of acidic gases showed N.D. or exceeded MDL concentrations but below lowest concentration of calibration line, indicating ambient acidic gases concentration was low. 4 types of PAHs were measured with Naphthalene being the highest (65.4 ng/m3) followed by Phenanthrene (4.7 ng/m3), indicating emissions of PAHs in the atmosphere of the district were low.
(3)Explained the reasons of air pollution levy on hazardous air pollutants in Yunlin County from 2011-2017. Among 13 VOCs, emissions of Toluene and Xylene topped the measurements. They also contributed most to the process emissions (738.4~1,070.9 tonne, 81.5~90.8 %). Confirmed the priority of regulating Benzene, Ethylene dichloride and chloroform after having taken into consideration of their impacts to human beings and in terms of carcinogenic emission volumes. Toluene should be listed as the top regulated substance since it contributed the greatest volume to the emissions of non-carcinogenic substances.
(4)Regarding investigation into emissions of major hazardous air pollutants in manufacturing processes, 15 times of exhaust duct testing, targeting “PU Leather Manufacturing Process”, “Gravure Printing Process”, “Plastic Tape Manufacturing”, “Acrylonitrile-Butadiene- Styrene Compounds (ABS) Chemical Manufacturing Process”, “Styrene Manufacturing Process” and “Phthalic Anhydride Manufacturing Process”, had been conducted for calculating emission coefficients. Emission coefficients were compared with coefficients obtained from similar local and overseas manufacturing processes. Results showed the emission coefficients obtained from this Project were lower than local and overseas figures, with 78.5-100 % difference.
(5)Based on the results of continuous monitoring of VOCs, relatively higher concentrations were obtained from industrial district. North location was being influenced by emissions from South East and South West directions while South location was being influenced by emissions from North West and North East directions.
(6)Except Acrylic, monthly average concentrations of all measurements in North location were below 5.0 ppb. Summer was the season with the highest average concentration. Monthly average concentration of Acrylic in June was 28.9 ppb, and 14.5 ppb in July, while other months have relatively lower concentrations. This was consistent to the time when factories were undergoing overhaul.
(7)Monthly average concentrations of all measurement results in South location were below 5.0 ppb. Except the measurements of acrylic and Butadiene in June to August having higher concentrations, other measurements have higher concentrations in winter than summer. This phenomenon was consistent with the influence of prevailing wind directions.
(8)Peak values of Acryl and Pentane in North location were record in July with 381.3 ppb and 56.9 ppb respectively while maximum value of Acryl in South location was recorded in June with 142.2 ppb. A measurement of Benzene with 104.4 ppb took place in September which exceeded the limit of 20.0 ppb under Stationary Sources of Hazardous Air Pollutants Emission Standards.
(9)28 detectable compounds among 87 VOCs were detected. Numbers of compounds with detectable ratios above and below 50 % are 7 and 21 respectively. 5 VOCs were detected at 12 monitoring stations. Methanol had the highest concentration (average 19.03 ppb) followed by Acetone (average 6.19 ppb), Toluene (average 1.21 ppb) and Methyl Ethyl Ketone (average 0.76 ppb) .
(10)3 carbonyl compounds were detected among 16 carbonyl compounds being monitored. There were three compounds with detectable ratio below 50 %.
(11)Ratio of 17 detectable dioxin-like compounds was all over 50 %. Despite XuCuo branch school had a higher mass concentration than JengChi Elementary School, JengChi Elementary School had higher Toxicity Equivalent Quotient (0.0229 WHO2005-TEQ/Nm3) than XuCuo branch school (0.0223 WHO2005-TEQ/Nm3) in terms of total PCDD/Fs pg WHO2005-TEQ/Nm3concentration. However, the difference was not obvious (p=0.914). Contributions of Dioxin concentration by XuCuo branch school and JengChi Elementary School were different, leading to difference in TEQ. This showed pollutions in these two places came from different sources. Besides, vehicle emissions could be one of the pollution sources for ambient PCDD/Fs in JengChi based on the results of Principle Component Analysis, PCA. Explanatory rate of XuCuo branch school had yet to reach 0.6 or above in order to confirm the possible sources of ambient dioxin. More data and information were needed.
(12)23 types of heavy metals, including Hexavalent Chromium and Mercury, were detected. 18 types of heavy metals with detectable ratio exceeded 50 % and the rest of the heavy metals were below 50 %. On the other hands, 14 types of heavy metals were detected at 12 monitoring stations with the concentration of Hexavalent Chromium being the highest (average 0.0442 µg/m3).
(13)17 types of Polycyclic Aromatic Hydrocarbons (PAHs) were detected. 4 types of PAHs with detectable ratio over 50 % whereas 13 types of PAHs were below 50 %. There were only 2 types of PAHs detected at 12 monitoring stations with the concentration of Naphthalene being the highest (60.7 ng/m3). Total measurement range in 12 PAHs samples at JengChi Elementary School was 87.1-205 ng/m3, and 0.09-0.20 in terms of total toxic equivalent quotient (Bapeq). Sources of PAHs in JengChi and XuCuo districts were likely to be the burning of industrial diesel based on the FLU/(FLU+PYR) in these two districts, which were 0.81 and 0.94 respectively.
(14)6 out of 10 types of acid and alkali gases were detected. 2 gases with detectable ratio of over 50 % whereas 4 gases were below 50 %. Besides, only Ammonia was detected at 12 monitoring stations.
