Ambient Air Quality MonitoringTechnique and Methods in China

China National Environmental Monitoring Center (CNEMC)

2013-10-22

Beijing, China

CONTENTS

• Monitoring standards and regulations

• Monitoring network and plans

• Routine monitoring method

• New monitoring method in future

Ambient air quality standard in China

Averaging time Primary standard Secondary standard

SO2

Annual

Daily

1-hour

20

50

150

60

150

500

NO2

Annual

Daily

1-hour

40

80

200

40

80

200

PM10

Annual

Daily

40

50

70

150

PM2.5

Annual

Daily

15

35

35

75

CODaily

1-hour

4.0

10.0

4.0

10.0

O3

8-hour

1-hour

100

160

160

200

• GB3095-2012 (issued 2012)

Others: TSP, NOx, Pb, B[a]p

μg/m3(except CO)

1. Standards and regulations

• Ambient Air quality standard• GB 3095-2012

• Monitoring methods and regulations• Technical regulation for ambient air quality index• Technical regulation for selection of ambient air quality

monitoring stations• Automated methods for ambient air quality monitoring• Manual methods for ambient air quality monitoring• ……

There are more than 40 regulations for ambient air quality monitoring

1. Standards and regulations

MEP is now building a complete ambient air quality monitoring regulation system to improve the monitoring program

2. Monitoring network and plans• National ambient air quality monitoring network

CNEMC

Urban air quality

National Ambient Air Quality

Monitoring Network

Regional air quality

Background air quality

Acid rain

Dust and Sandstorm

Green house gases

1436 sites

in 338 cities

31 sitespresent

15 sitesIn all

431 sites

in 347 cities

31 sites in all

82 sites in 82 cities

2. Monitoring network and plans

• Locations of urban monitoring sites

urban sites

There are 1436 urban sites from 338 cities

2. Monitoring network and plans

• An urban air quality monitoring site in Tianjin, China

2. Monitoring network and plans

• An urban site usually represents an area of 25 km2 , and it was population originated

• Purpose of urban sites• Judge the attainment of air quality standard• Report the air quality information timely to public• Assess the effects of air pollutants on human health

2. Monitoring network and plans

Good0-50

Unhealthy 151-200

Moderate51-100

Very Unhealthy201-300

Unhealthy for Sensitive Groups101-150

Hazardous 301-500

AQI categories

668 urban sites from 114 cities has reported air quality index hourly

2. Monitoring network and plans

2. Monitoring network and plans

• Locations of regional monitoring sites

regional sites

There are only 31 regional sites, i.e. one for each province

65 other regional sites will be built during year 2013 to year 2015

2. Monitoring network and plans

• Regional air quality monitoring site in Sichuan, China

2. Monitoring network and plans

• A regional site usually represents an area of 20km×20km

• Purpose of regional sites• Monitoring air pollutants at regional level• Evaluate the effect of regional scale air pollution

prevention measurements • Monitoring the transferring of air pollutants between cities• Serve for the regional air quality warning and forecasting

2. Monitoring network and plans

• Locations of background monitoring sites

background sites

There are 15 background sites, all located in national natural reserves

2. Monitoring network and plans

• Shen Nong-jia background site in Hubei province, China

2. Monitoring network and plans

• Purpose of background sites• Monitoring air pollutants at background level• Evaluate the effect of air pollutants on ecologic system• Used for scientific research and international

cooperation

• A background site usually represents an area of more than 50km×50km

2. Monitoring network and plans• Monitoring parameters at each site

Parameters/Equipment

Urban site

Regional site

Background site

Dust site

Acid rain

Greenhouse

SO2 ▲ ▲ ▲ - - -

NO/NO2/NOX ▲ ▲ ▲ - - -

PM10 ▲ ▲ ▲ ▲ - -

PM2.5 ★ ▲ ▲ ○ - -

CO ★ ▲ ▲ - - -

O3 ★ ▲ ▲ - - -

TSP ○ ○ ○ ▲ - -

Pb ○ ○ ○ - - -

VOCs/B[a]p ○ ○ ○ - - -

Precip./pH/EC,Ions - ▲ ▲ - ▲ -

Lidar ○ ○ ○ ○ - -

CO2/CH4/NMTH - ▲ ▲ - - ▲

▲Required

○Optional

★Required in 2016

-Not required

3. Routine monitoring method

• Manual monitoring methods for criteria pollutants take a great part before year 2000

• Automated monitoring methods has gradually been widely used after that

• Manual reference methods of PM were used to audit and calibrate the automated instrument

3. Routine monitoring method

Air pollutants Monitoring method

SO2 Ultraviolet fluorescent method,DOAS

NO-NO2-NOX Chemiluminescence detection method, DOAS

O3 Ultraviolet photometric method ,DOAS

CO Gas filter correlation/Non-dispersive infrared absorption method,

PM10 β -ray absorption method, TEOM

PM2.5 β -ray absorption method, TEOM

• Routine automated monitoring methods

3. Routine monitoring method

• Automated Instruments • Abroad : Thermal fisher, Ecotech, API, Daxibi, ESA…… • Domestic: Xianhe, TH, Landun

• The domestic air quality instrument has had a great development in recent years.

3. Routine monitoring method

• An urban monitoring site in Tianjin, China

3. Routine monitoring method

• An urban monitoring site in Wuhan, China

4. New monitoring method in future

• Methods: • Multi-axial differential optical absorption spectroscopy

(MAX-DOAS)• Lidar

• Applied areas• Regional transmit flux of air pollutants• Sand storm monitoring• Emission sources and industrial areas monitoring

Remote monitoring technology MAX-DOAS

平 流 层

观测角度仪器

对流层

Multi-axial differential optical absorption spectroscopy Multi-axial differential optical absorption spectroscopy （（ MAX-DOAMAX-DOA

SS））

MAX-DOAS is a kind of passive spectrum technology, it received solar spectra from different elevation angles. The absorption spectrum could be resolved to obtain the columnar concentration and profile of air pollutants (such as SO2 NO2 CO O3)

Flux research ： mobile MAX-DOAS

,i wind i car i iFlux V VCD V t IIFRSFRS IImesmes

We can research the emission flux of a single point pollution source or an industrial zone by using mobile max-doas

v

factory

a. Point source ：Through monitoring the stack plume cross section at downwind direction by using mobile max-doas, meanwhile, observing the meteorological parameter, we can get the emission flux.

FluxFlux ＝＝∑∑ FluxFluxii

b. industrial zone:Through  calculating the difference between the

influx at upwind and outflow at downwind, we can

evaluate the net flux of an industrial area

Flux 净＝ Flux 入－ Flux 出

Flux research ： mobile MAX-DOAS

瞬态

记录仪

信号

大气

激光器 望远镜

计算机

探测器

激光雷达 (Lidar)

Remote monitoring technology Lidar

Lidar is used to monitor particles in vertical direction, for example in dust and sand storm monitoring

Remote monitoring technology Lidar

Spherical Non-Spherical

laser laser

Laser echo

Laser echo

Depolarization radio = P⊥/ P∥

The initial emission laser was linear polarized due to the Crystal nature of laser medium.

the spherical particles do not change the polarization properties of laster echo while the non-spherical particles have obvious depolarization effects.

We can distinguish the spherical particle and non-spherical particle through the different depolarization ratio.

coefficient of light extinction

depolarization ratio

Local pollution

Sand storm

Local pollution

Sand storm

Ice cloud

Ice cloud

water cloud

water cloud

Environmental Monitoring center can monitor the air pollutants columnar concentration and reseach the transmission flux among dividual areas.

MAX-DOAS and Lidar were successfully applied to air quality monitoring and forecast during the 29th the Olympic Games in Beijing ,the 53th World Expo in Shanghai, and the 16th Asian Games in Guangzhou.

Remote monitoring technology

THANK YOU FOR YOUR ATTENTION!