I. Motive & Pre-work
Leafing through the past
newspaper of Hsien-Hsi, we found the shocking news of dioxin incident but it was disappointing
that they made the conclusion hurriedly with no completed explanation, so we’d
like to find this incident out. First, we did the initial work to understand
the relevant units involved in this incident, such as duck farmers, Environment
Protection Administration, and Taiwan Steel Union. To look up the relevant
dioxin control and inspection task, we asked Changhua Environment Protection
Agency and they replied that they authorized Worthies Cooperation to assist
them, so we contacted with Worthies and arranged the visiting schedule to make
us get the specific and clear information. (EPA authorizes consultant companies
or schools to deal with relevant things, and pay them from the air pollution penalty
for vehicles, factories, and construction sites.)
II. Pre-understanding of Worthies
The full name for Worthies Cooperation is Worthies Environmental Engineering
Consultants Cooperation. It is located in Taichung Industrial Park and founded
in April 1996. It is engaged in environmental assessment, life and industry
waste water disposal, industry water disposal, solid waste disposal, instruction
supervision and operation maintenance at home and abroad. They founded the
first private ultramicro environment inspection laboratory in Taiwan in June
2001. They own two high resolution gas chromatography mass spectrometers in lab with
the largest investment scale of professional dioxin analysis inspection in
domestic, and they are the dioxin inspection origination with the richest
analysis experience.
The main inspection items for Worthies are dioxin,
waste and soil, and the project execution items are sampling, noise control,
water disposal, waste gas disposal, environmental assessment, polluted soil
investigation, and etc.
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III. Visiting SchedulesIt
should be manager Mr. Tsao Tien Sheng to receive us and make the presentation originally,
but Mr. Tsao was temporarily called to deal with things by EPA; therefore, vice
manager Lin Yung Hsiang substituted for him to make the presentation to us.
Before we talked about the topic, Mr. Lin told us that the air pollution and
dioxin in Changhua district are monitored by Yenping Station and the air
pollution in Hsien-Hsi is monitored by Hsien-Hsi High School Station, but the
forward analysis of dioxin is undertaken by their company.
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1. Company Experience
First, Mr Lin mentioned that our local government has no inspection ability of micro toxic laboratory, so the relevant inspections are authorized to universities or environmental engineering companies like Worthies to execute projects, and Worthies has accumulated many experience for years. They has undertaken “inspection plan,” ” patrol investigation and decrement guidance plan” and “perimeter air, soil and plant sampling and analysis plan” about dioxin heavy metal for many counties and EPA.
First, Mr Lin mentioned that our local government has no inspection ability of micro toxic laboratory, so the relevant inspections are authorized to universities or environmental engineering companies like Worthies to execute projects, and Worthies has accumulated many experience for years. They has undertaken “inspection plan,” ” patrol investigation and decrement guidance plan” and “perimeter air, soil and plant sampling and analysis plan” about dioxin heavy metal for many counties and EPA.
The authorized tasks by
Changhua Environment Protection Agency are as follows:
- Regular dioxin and heavy metal inspection on
factories to check if the work is complied with Act and system.
- Inspection on perimeter
air, especially for Chuanhsing and Changhua Coastal Industrial Park as
important area.
- Guidance and improvement
on substandard factories to meet the qualified standard.
- Pollution inspection
database build-up for future analysis and comparison.
2. Control on Dioxin Emission Source
Control on dioxin emission source as follow:
There are 34 factories, 9 manufacture procedures and 44 chimneys under control in Changhua County Government.
Most controlled factories meet the standard, but we should take note of the small unregistered factories everywhere. The poor environment equipment and waste water discharge in long term would cause great damage to environment.
Control on dioxin emission source as follow:
There are 34 factories, 9 manufacture procedures and 44 chimneys under control in Changhua County Government.
Most controlled factories meet the standard, but we should take note of the small unregistered factories everywhere. The poor environment equipment and waste water discharge in long term would cause great damage to environment.
3. Semi-volatility Substance - Dioxin
1) Brief introduction of dioxin
It is resulted from substance with chlorine; for example, burning plastic products would produce dioxin.
Dioxin isn’t only one substance, but it is composed of 210 different kinds of chemical compound. With present technology, we could analyze 136 kinds, but we usually analyze 17 kinds which are more toxic.
However, the dioxin pollution couldn’t be monitored instantly, we only could sample it instantly or do post-analysis. Although it will be destroyed over 850°C, it would be re-compounded during the cooling process of general manufacture procedures; therefore, most dioxin pollution from factories is “re-compounded dioxin.”
2) Efficient disposal of dioxin
The efficient disposal of dioxin is to add active carbon during procedure, and it would be absorbed and filtered through dust collector. However, unworthy factories use poor quality active carbon which lowers the effect of dioxin absorption and causes pollution. (Normally, we use iodine value to analyze the absorption amount of active carbon; good active carbon could absorb at least 800 to 900 units per kilogram, but poor one would absorb under 800 to 900 units even only 300 units.) If people follow the Act technology in dioxin prevention, the value won’t be over standard, unless the carelessness of maintenance.
1) Brief introduction of dioxin
It is resulted from substance with chlorine; for example, burning plastic products would produce dioxin.
Dioxin isn’t only one substance, but it is composed of 210 different kinds of chemical compound. With present technology, we could analyze 136 kinds, but we usually analyze 17 kinds which are more toxic.
However, the dioxin pollution couldn’t be monitored instantly, we only could sample it instantly or do post-analysis. Although it will be destroyed over 850°C, it would be re-compounded during the cooling process of general manufacture procedures; therefore, most dioxin pollution from factories is “re-compounded dioxin.”
2) Efficient disposal of dioxin
The efficient disposal of dioxin is to add active carbon during procedure, and it would be absorbed and filtered through dust collector. However, unworthy factories use poor quality active carbon which lowers the effect of dioxin absorption and causes pollution. (Normally, we use iodine value to analyze the absorption amount of active carbon; good active carbon could absorb at least 800 to 900 units per kilogram, but poor one would absorb under 800 to 900 units even only 300 units.) If people follow the Act technology in dioxin prevention, the value won’t be over standard, unless the carelessness of maintenance.
4. Equipment Visiting and introduction
Next, the lab manager took over, and took us to understand how to sample, collect, concentrate, purify and analyze dioxin from factory exhausts.
1. Sampling
First, the long pipes are stretched into factory exhausts, and inspectors will investigate the weather condition in advance and regulate the speed of air-in at any time. Since the concentration of dioxin is very low, it will take over 48 hours to sample. This is a tough task.
Next, the lab manager took over, and took us to understand how to sample, collect, concentrate, purify and analyze dioxin from factory exhausts.
1. Sampling
First, the long pipes are stretched into factory exhausts, and inspectors will investigate the weather condition in advance and regulate the speed of air-in at any time. Since the concentration of dioxin is very low, it will take over 48 hours to sample. This is a tough task.
2. Extraction
Use Soxhlet extraction process to concentrate and purify the sample.
Use Soxhlet extraction process to concentrate and purify the sample.
●What is Soxhlet extraction
process?
Extraction is the "pulling out" of a substance from one phase by another phase. The resulting organic product can be purified because of removal of a desired compound from a solid or liquid mixture. Soxhlet extraction is one of the extraction techniques.
● Steps in Soxhlet extraction: (Worthies uses Soxhlet extraction to increase the concentration of sample.)
Extraction is the "pulling out" of a substance from one phase by another phase. The resulting organic product can be purified because of removal of a desired compound from a solid or liquid mixture. Soxhlet extraction is one of the extraction techniques.
● Steps in Soxhlet extraction: (Worthies uses Soxhlet extraction to increase the concentration of sample.)
- Grind the solid substance before extraction to increase the contact area between substance and solvent.
- Put the solid substance in filter paper case.
- Install a round bottom flask with solvent under the extractor, and connect it with backflow condenser pipe above.
- Heat the round bottom flask to make solvent vaporize through the condenser pipe of the device, and the vaporized solvent would be condensed to drop into extractor. Extract after the solvent contacted with the solid mixture in filter paper case, extract a pat of abstract, and increase the concentration of it by repeating the vaporization and condensation process.
3. Analysis
- Worthies purchased the latest model of high resolution gas chromatography mass spectrometer (MS-700D) for two sets from JEOL, and complete 10 samples per batch. The most analysis capacity everyday would be 20 chimneys.
- Extract first, concentrate it into a small drop and put it in a small bottle.
- Inject the sample around 10cc at one time into heated glass bottle, heat it up to 290°C and enter ion source (about 10,000 volt).
- Separation theory depends on ion source, since it will generate thermion (negative electricity) and make dioxin become positive electricity.
- Positive ion gets through mass spectrometer to the detector behind, and it will be detected. The higher the concentration is, the higher the detection value is.
- Two principles, for high temperature and oxidation, are used in machine.
IV . Conlusion
Everyone has his goal and
expectation. The point is the reflection from dioxin incident.
ReferenceReference (Traditional Chinese Websites)
- 公司沿革 - 仲禹工程顧問股份有限公司,http://www.worthies.com.tw/about.htm
- 索氏萃取法 - 行政院環境保護署環境檢驗所,http://www.niea.gov.tw/niea/REFSOIL/M16500C.htm