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

9th December, 2005

A Workshop jointly organized by the EMB and

the Department of Chemistry Hong Kong Baptist University

Date : 9th 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)

Participants will be divided into 4 groups to browse through the four teaching kits (4 x 15 min)

Demonstrating Demonstrating Environmental Chemistry Environmental Chemistry

with Case Studieswith Case Studies

(1)(1)A worrying issue – green House A worrying issue – green House EffectEffect

(2)(2) A pressing problem – Air Quality A pressing problem – Air Quality of Hong Kongof Hong Kong

(3)(3) River water – Our invaluable River water – Our invaluable assetasset

(4)(4) Alcohol, Chemistry and You - Alcohol, Chemistry and You - breathalyzerbreathalyzer

One Earth One Earth our changing global our changing global

environmentenvironment One Future One Future

To execute our ownership to the To execute our ownership to the Environment, we should be aware of Environment, we should be aware of

current environmental issuescurrent environmental issues

Our exposure to the knowledge of Our exposure to the knowledge of Environmental Science enable us to Environmental Science enable us to make informed judgments on crucial make informed judgments on crucial

issuesissues

Close relationships among the air, water, earth and living Close relationships among the air, water, earth and living organismorganism

Environmental ChemistryEnvironmental Chemistry

May be defined as the study of May be defined as the study of the sources, reactions, the sources, reactions,

transport, effects and fates of transport, effects and fates of chemical species in water, soil chemical species in water, soil and air environments and the and air environments and the effect of technology thereineffect of technology therein

Objectives of the ProjectObjectives of the Project• Students can gain an adequate appreciation oStudents can gain an adequate appreciation o

f environmental chemistry by doing laboratory f environmental chemistry by doing laboratory activitiesactivities

• With the aid of a low-cost photometer and/or With the aid of a low-cost photometer and/or microscale teaching kits, many environmental microscale teaching kits, many environmental issues could be presented in a more quantitatiissues could be presented in a more quantitative manner (more vigorous treatment)ve manner (more vigorous treatment)

• The developed teaching kits can be utilized to The developed teaching kits can be utilized to conduct investigative studies as follow-up acticonduct investigative studies as follow-up activitiesvities

Template for constructing Template for constructing casescases

• Topic directing questionsTopic directing questions

• Experimental design & setupExperimental design & setup

• Experimental operations and Experimental operations and observationsobservations

• Learning outcome from the activityLearning outcome from the activity

• Presentation of the key issues of the Presentation of the key issues of the activityactivity

Case oneCase one

A worrying issue A worrying issue

- green House - green House EffectEffect

Topic directing questions:Topic directing questions:• What is the “green house effect”? What is the “green house effect”? • What is the relation between the emission What is the relation between the emission

of excessive green house gas and global of excessive green house gas and global warming phenomenon?warming phenomenon?

• What are green house gases?What are green house gases?• Can we do something to alleviate the Can we do something to alleviate the

global warming problem?global warming problem?• Can we prove the existence of the effect of Can we prove the existence of the effect of

green house gas experimentally?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 & Experimental design & setupsetup• The use of “Green House Simulator” to verifThe use of “Green House Simulator” to verif

y the heating effect of carbon dioxide to the eny the heating effect of carbon dioxide to the environment.vironment.

• Emission source: generating COEmission source: generating CO22 by microscal by microscale chemistry e chemistry

• NaNa22COCO33 + 2 HCl = 2 NaCl + CO + 2 HCl = 2 NaCl + CO22 + H + H22OO• Locate a light source to simulate the SunLocate a light source to simulate the Sun• Observe the temperature increase in COObserve the temperature increase in CO2 2 enricenric

hed compartmenthed compartment

Three degree difference could be observed.

Learning outcome from the Learning outcome from the activityactivityStudents should understand Students should understand

Carbon dioxide is a green house gas systemCarbon dioxide is a green house gas systemGreen house gases can heat up the Green house gases can heat up the

environment environment The set up can be used to prove O2 (or other The set up can be used to prove O2 (or other

gases) is not a green house gasgases) is not a green house gasTheoretically, the “heat up effect” is related Theoretically, the “heat up effect” is related

to the concentration of COto the concentration of CO22 in the in the compartment compartment

Case twoCase two

A pressing problemA pressing problem

-Air Quality of Hong -Air Quality of Hong KongKong

Topic directing questions:Topic directing questions:• What are the major air pollutants present in our What are the major air pollutants present in our

environment?environment?• What are the health adverse effects of poor air What are the health adverse effects of poor air

qualities on human beings?qualities on human beings?• Do we have any hard evidences which show that the Do we have any hard evidences which show that the

air quality of Hong Kong is getting worse over recent air quality of Hong Kong is getting worse over recent years?years?

• What air quality parameters have been adopted by What air quality parameters have been adopted by the EPD to quantify the air quality of Hong Kong on the EPD to quantify the air quality of Hong Kong on the day-to-day basis?the day-to-day basis?

• Can HK EPD impose more stringent measures to Can HK EPD impose more stringent measures to improve the air quality of Hong Kong?improve the air quality of Hong Kong?

• What happens to lead when it is released to the What happens to lead when it is released to the environment?environment?

• Can an individual do something to help the situation?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, NO2, SO2 and O3 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, O3, NO2 and SO2) 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

GradeGrade ValueValue Regional air quality Regional air quality conditionsconditions

II 0-10-1 Pollutant concentrations are welPollutant concentrations are well within the air quality standards l within the air quality standards

IIII 1-21-2 Pollutant concentrations are genPollutant concentrations are generally within the air quality standerally within the air quality standardsards

IIIIII 2-32-3 Concentrations of individual pollConcentrations of individual pollutants may approach or exceed tutants may approach or exceed the air quality standardshe air quality standards

IVIV 3-43-4 Air quality standards are generallAir quality standards are generally exceededy exceeded

VV >4>4 Air quality standards are significAir quality standards are significantly exceededantly 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. NO2, SO2, TSP and O3)

Active sampling pump

Passive sampler

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!

We can set up a project of using the kit to find the air lead content

The kit allows us to obtain air quality data related to the RAQI.

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 and ammonia-nitrogen, 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:pH 6.5-8.5Suspended solids: annual median < 20 mg/LDissolved oxygen: > 4 mg/LBOD5: < 3 mg/LCOD: < 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 (BOD5) and ammonia-nitrogen, is used to indicate the extent of organic contamination of the rivers. The WQI is an indicator for protecting aquatic life.

No. of poiNo. of points awardnts award

eded

DO levelDO level(% saturation) (% saturation)

BODBOD55

(mg/L)(mg/L) Ammonia-NiAmmonia-Ni

trogentrogen (mg/L)(mg/L)

11 91-11091-110 <3<3 <0.5<0.5

22 71-9071-90 3.0-6.03.0-6.0 0.5-1.00.5-1.0

33 51-7051-70 6.1-9.06.1-9.0 1.1-2.01.1-2.0

44 31-5031-50 9.1-159.1-15 2.1-5.02.1-5.0

55 <30<30 >15>15 >5.0>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

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。 .

Alcohol, Chemistry and YouBREATHALYZER

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。

A “breathalyzer” fabricated by the ChemEDU 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.

Semi-quantitative device for ethanol determination

The demonstration can be executed within 5 min with clear illustration of the principle.

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).

Follow up Project (s)

LEDs-based PhotometerLEDs-based Photometer

The Department The Department of Chemistry, Hof Chemistry, Hong Kong Baptiong Kong Baptist University hst University has designed anas designed and fabricated a d fabricated a versatile 4- chaversatile 4- channel LEDs basennel LEDs based photometer. d photometer.

Homemade LEDs-based photometer- manufactured by ChemEdu

LEDs-based PhotometerLEDs-based PhotometerReason for choosing LED as light sourceReason for choosing LED as light sourceLED emits radiation in the visible region LED emits radiation in the visible region

Color of LEDColor of LED Peak Peak Emission Emission WavelengthWavelength

Spectral Spectral Bandwidth Bandwidth (FWHM)(FWHM)

BlueBlue 465nm465nm 25nm25nm

GreenGreen 525nm525nm 36nm36nm

YellowYellow 590nm590nm 35nm35nm

RedRed 626nm626nm 45nm45nm

Table 1.1 Summary of LED’s color, peak emission wavelength and spectral bandwidth

THANK YOU FOR YOUR ATTENTION

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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 c

hemical education in Asian countries.