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Quantitative Studies of Environmental Chemistry with Education Teaching Kits 陳永康教授 香港浸會大學化學系 A sharing workshop Jointly presented by the EMB & Department of Chemistry, HKBU 9 th December, 2005
A Workshop jointly organized by the EMB and the Department of Chemistry Hong Kong Baptist University Date : 9 th December, 2005 Time : 4: 00 – 5: 45 pm Program: 1. A presentation “Quantitative Studies of Environmental Chemistry with Education Teaching Kits” delivered by Prof. W. H. Chan (45 min) 2. Demonstration of the Teaching Kits (1 hr) 3. Participants will be divided into 4 groups to browse through the four teaching kits (4 x 15 min)
Demonstrating Environmental Chemistry with Case Studies (1)A worrying issue – green House Effect (2) A pressing problem – Air Quality of Hong Kong (3) River water – Our invaluable asset (4) Alcohol, Chemistry and You breathalyzer
One Earth our changing global environment One Future To execute our ownership to the Environment, we should be aware of current environmental issues Our exposure to the knowledge of Environmental Science enable us to make informed judgments on crucial issues
Close relationships among the air, water, earth and living organism
Environmental Chemistry May be defined as the study of the sources, reactions, transport, effects and fates of chemical species in water, soil and air environments and the effect of technology therein
Objectives of the Project • Students can gain an adequate appreciation of • • environmental chemistry by doing laboratory activities With the aid of a low-cost photometer and/or microscale teaching kits, many environmental issues could be presented in a more quantitative manner (more vigorous treatment) The developed teaching kits can be utilized to conduct investigative studies as follow-up activities
Template for constructing cases • Topic directing questions • Experimental design & setup • Experimental operations and observations • Learning outcome from the activity • Presentation of the key issues of the activity
Case one A worrying issue - green House Effect
Topic directing questions: • What is the “green house effect”? • What is the relation between the emission of • • • excessive green house gas and global warming phenomenon? What are green house gases? Can we do something to alleviate the global warming problem? Can we prove the existence of the effect of green house gas experimentally? A class group discussion on some of the above questions will motivate the students’ interests on subsequent presentation of the key issue.
Experimental design & setup • The use of “Green House Simulator” to verify the • • heating effect of carbon dioxide to the environment. Emission source: generating CO 2 by microscale chemistry Na 2 CO 3 + 2 HCl = 2 Na. Cl + CO 2 + H 2 O Locate a light source to simulate the Sun Observe the temperature increase in CO 2 enriched compartment
Three degree difference could be observed.
Learning outcome from the activity Students should understand Carbon dioxide is a green house gas system l Green house gases can heat up the environment l The set up can be used to prove O 2 (or other gases) is not a green house gas l Theoretically, the “heat up effect” is related to the concentration of CO 2 in the compartment
Case two A pressing problem -Air Quality of Hong Kong
Topic directing questions: • What are the major air pollutants present in our • • • environment? What are the health adverse effects of poor air qualities on human beings? Do we have any hard evidences which show that the air quality of Hong Kong is getting worse over recent years? What air quality parameters have been adopted by the EPD to quantify the air quality of Hong Kong on the dayto-day basis? Can HK EPD impose more stringent measures to improve the air quality of Hong Kong? What happens to lead when it is released to the environment? Can an individual do something to help the situation?
藍天不在 Where is the blue sky?
Air Pollution Problems in Hong Kong and in the Pearl River Delta (PRD) are the concerns of the HKSAR Government, as well as the general public. How bad is our environment in terms of the air qualities? We need a more quantitative picture to understand the present situation.
In the air monitoring stations operated by the HKEPD, quantitative data on TSP, RSP, Pb, CO, NO 2, SO 2 and O 3 are collected continuously with expensive instrument.
Regional Air Quality Index (RAQI)
Starting from December 1, 2005, the RAQI of 16 monitoring stations is calculated and reported at 4: 00 pm daily. Among the 16 monitoring stations, 13 are in China, 3 in Hong Kong. The value was based on four parameters collected (i. e. RSP, O 3, NO 2 and SO 2) in the past 24 hr (2: 00 pm -2: 00 pm) in the 14 stations. The lower the grading the better the air quality will be.
Regional Air Quality Index (RAQI) Grading Grade I II Value Regional air quality conditions 0 -1 Pollutant concentrations are well within the air quality standards 1 -2 Pollutant concentrations are generally within the air quality standards III 2 -3 Concentrations of individual pollutants may approach or exceed the air quality standards IV 3 -4 Air quality standards are generally exceeded V >4 Air quality standards are significantly exceeded
To provide students with the real experience in taking some of those air quality parameters, we have designed a set of low-cost instrument which can be used to measure four parameters (i. e. NO 2, SO 2, TSP and O 3) Passive sampler Active sampling pump
Establishing the air quality information within your campus Getting the data in different time of the day, to see the one profile of the air pollutants How about taking the kit to the busy street to get the roadside data! The kit allows us to obtain air quality data related to the RAQI. We can set up a project of using the kit to find the air lead content
CASE THREE River Water -Our invaluable Asset
The water quality of hundreds of rivers and streams in Hong Kong has been monitored by the Environmental Protection Department (HKEPD). A simple Water Quality Index (WQI), based on the level of dissolved oxygen, 5 day Biochemical Oxygen Demand ammonianitrogen, is used to indicated the extent of organic contamination of the rivers.
The quality of water reflected by these parameters is compared with the statutory WQOs set by the EPD. For instance, below figures show several WQOs adopted by the EPD: p. H 6. 5 -8. 5 Suspended solids: annual median < 20 mg/L Dissolved oxygen: > 4 mg/L BOD 5: < 3 mg/L COD: < 15 mg/L
Would there be a simplified system to indicate the water quality of rivers in Hong Kong? In addition to the WQOs, a Water Quality Index (WQI), based on the level of dissolved oxygen (DO), 5 -day Biochemical Oxygen Demand (BOD 5) and ammonianitrogen, is used to indicate the extent of organic contamination of the rivers. The WQI is an indicator for protecting aquatic life.
No. of points awarded DO level (% saturation) BOD 5 (mg/L) Ammonia. Nitrogen (mg/L) 1 91 -110 <3 <0. 5 2 71 -90 3. 0 -6. 0 0. 5 -1. 0 3 51 -70 6. 1 -9. 0 1. 1 -2. 0 4 31 -50 9. 1 -15 2. 1 -5. 0 5 <30 >15 >5. 0
The three WQI parameters of water samples can be determined by the teaching kit.
Potential uses of the WATER QUALITY PARAMETERS kit • Conduct analysis for surface water samples from different sources • Conduct analysis for fabricated waste water samples with organic waste materials • Determine the DO dependence on temperature
Alcohol, Chemistry and You BREATHALYZER 酒後駕車累己害人，將引致死亡和身體心靈變損傷。 酒後駕車是觸犯刑事，警方有權使用呼氣測試器去測試懷 疑醉酒駕車者的呼氣酒精含量是否超標。.
警方有權在現塲截停車輛, 並使用呼氣測試器進行 酒精的呼氣測試，為確認化驗結果，警方可進一 步取樣進行血液和尿液的測試。由 1999年 10月 開始，法例規定駕駛者血液酒精含量必須 每 100毫升血中少於 50毫克酒精 每 100毫呼氣中少於 22微克酒精 每 100毫升尿液中少於 67毫克酒精 任何駕車者，若身體樣本超過以上法例的指標上 限，將會受到檢控。
Semi-quantitative device for ethanol determination A “breathalyzer” fabricated by the Chem. EDU has been developed as a teaching aid to demonstrate to the students: Ethanol can be oxidized to acetaldehyde and acetic acid by dichromate coated on silica gel.
The demonstration can be executed within 5 min with clear illustration of the principle.
Follow up Project (s) Create your own experiment: • Using the device to determination the ethanol content of common beavarges (i. e. wine, beer, chinese wine etc. ) • To prove, by passing through the cartridge, ethanol is converted to acetic acid and/or acetaldehyde (qualitatively and quantitatively).
LEDs-based Photometer The Department of Chemistry, Hong Kong Baptist University has designed and fabricated a versatile 4 channel LEDs based photometer. Homemade LEDs-based photometermanufactured by Chem. Edu
LEDs-based Photometer Reason for choosing LED as light source u. LED emits radiation in the visible region Table 1. 1 Summary of LED’s color, peak emission wavelength and spectral bandwidth Color of LED Peak Emission Wavelength Spectral Bandwidth (FWHM) Blue 465 nm 25 nm Green 525 nm 36 nm Yellow 590 nm 35 nm Red 626 nm 45 nm
THANK YOU FOR YOUR ATTENTION PLEASE VISIT OUR WEBSITE www. hkbu. edu. hk/~iwlcimc If you wish to receive our updated development of teaching kits, you can provide us with your Email. Under the auspices of the FACS (Federation of Asian Chemical Societies), the project “Low-cost instrumentation and microscale chemistry” has been undertaken at this University with the aim to support the chemical education in Asian countries.