Creating air pollution map and analyzing traffic survey with VNU-HCM students

Osaka Prefecture University

Tomofumi Kiyose

Yusuke Suda

Takako Yamazaki

Air pollution

Economy of Vietnam is significantly developing

Reason of air pollution： ◆Rapid economic growth ◆Growth of populations ◆Major development of industries

Especially problems in urban area

Emission from motor bikes, cars, etc. Air pollutions（CO2, NOx etc.）

Air pollutants increase in Vietnam

2Background

Purpose

Air monitoring by setting equipment in Ho Chi Minh city. →make pollution map

Compare with the result of same experiment last several year.

→discuss about the change of the pollution in Ho Chi Minh city

Sampling with Vietnamese students →attend in international joint study

3

Materials & Methods

to identify the factor of air pollution clearly

4

49 sampling points

to measure NO2 ,NH3 ,O3

1. Passive Sampler

2. Filter pack

4 sampling points

to measure PM2.5, HNO3, HONO, NO2 and NH3

3. Traffic Count

Materials & Methods

2

34

1 4

6

1 5

1 9

9

2 0

1 1

1 2

4 2

1 6 1

3

2 8

1

2 5

2 22

32 7

1 7

1 8

4 5

2 6

2 1

4 3

3 9

4 7

4 8

4 4

4 6

4 9

3 5

3 6

3 4

3 3

3 7

3 1

3 2

4 0

4 1

8

1 0

5 2 4

3 0

7

VNUHCM

Passive samples

+ Filter Pack

City area

What is passive sampler?

Sampler : low Atmosphere : high

Trapping filter

Diffusion of gaseous particles resulted from difference of the gaseous concentration

Principle of passive sampler

○Advantage *Not use power source *Small and light *Low cost *Easy to set and collect

×Disadvantage *Variation is over 10 %

Passive sampler

Air height : 19 mm diameter : 30 mmφ

pore size:1.0 mm

remove particles and water drop

Teflon filter

Filter include chemical

To catch NH3 → H3PO4 O3 → NaNO2 NO2 → N(CH2CH2OH)3

Filter pack

○Advantage

*Small and light

*Can collect samples where is no analyzers

×Disadvantage

Need power source

Analysis

Filter pack

pump

F7: TEA 20 %(NO2) F8: TEA 20 %(NO2)

0.1 L/min

3.9 L/min

Calculation

HONO concn. : F4－F5

NO2 concn. : F5×2+F7+F8

MFC

4.0 L/minAir MFC

F1: Donut filter(particle >2.5 µm) F2: Quartz filter(PM2.5) F3：NaCl(HNO3 all) F4: Na2CO3(HONO all、NO2 about 2 %) F5: Na2CO3(Compensate for NO2 of F4) F6: H3PO4 (NH3 all)

Analytical method

Passive sampler (49 places)

Material Analytical method

NH3 IC

NO2 UV-vis

O3 UV-vis

Filter pack sampler (4 places)

Material Analytical method

PM2.5 Weight measurement

HONO IC

HNO3 IC

NH3 IC

NO2 UV-vis

Program schedule

Passive sampler

Filter pack Activity

21/8 Group meeting Welcome party

22 set set Plastic factory

23 Mekong Delta

24 Change filter Dalat travel

25

26 Change filter City tour & Culture exchange program

27 Water park

28 Collect sample Collect samples Karaoke & city tour

29 Analyzing Super market

30 Presentation Ben Tanh market

Keep

Pollution Map：NH3 (2018)

Big Highway

2 km

Tan Binh Dist

Dist. 9

Dist. 2

Dist. 4

Dist. 1

Dist. 3

Dist. 10

Dist. 11

Dist. 6

Dist. 8 Dist. 7

Dist. 5

Dist. 12

Thu Duc Dist.

Binh Chanh Dist.

Hoc Mon Dist.

Binh Thanh Dist.

Phu Nhuan Dist.

Go Vap Dist.

NH3 ppb 75 ~

50 to 75

25 to 50

0 to 25

Saigon River

Big Highway

City area

2018

Emission source： Waste water

NH3 Comparison 2017-18

NH3 ppb 75 ~

50 to 75

25 to 50

0 to 25

2017 2018

Saigon River

Location trend is almost same

Big Highway Big Highway

Saigon River

NO2 Comparison 2017-18

NO2 ppb 75 ~

50 to 75

25 to 50

0 to 25

2017 2018

Compare 2018 with 2017 • NO2 concentration is higher than that of 2017.

• It had not rained much in the measurement period. 2NO2 + H2O → HONO + HNO3

NO2 ppb 30 ~

20 to 30

10 to 20

0 to 10

15

O3 Comparison 2016-18

2018

Different trend

[Counting period] 7 a.m. ～ 6 p.m., for 5min / 1h

[Place] • Front of VNUHCM (NVC street) • Both street (South & North side)

Standard Heavy duty Motorbike

[Type]

Traffic count

VNUHCM

0

2000

4000

6000

8000

10000

12000 Bike / Monday to South

0

2000

4000

6000

8000

10000

12000

27/8/2018

28/8/2017

29/8/2016

Bike / Monday to North

N u

m b

e r

o f

v ie

c le

s / h

o u

r Result：Traffic count

◆In the morning: North > South

→to go center of city

◆In the evening: South > North

→to go home

Direction to center of city

VNUHCM

Office area

Bed town

Bed town

Bed town

Bed town

Conclusion

NH3: Concentration, location trend is

same to 2017.

NO2: Concentration is higher than 2017.

Location trend is similar.

O3: Concentration is lower than 2016,2017.

Location trend is opposite from last two years.

But this year,

NH3,NO2,O3 are high value in city area.

19