measurement of ambient air pollutants, sampling and analysis

MEASUREMENT OF AMBIENT AIR POLLUTANTS: SAMPLING AND ANALYSIS

Abhishek Tiwari

11M180157

AIM

To make an estimation major air pollutants viz. PM 10, PM 2.5 , SO2 and NO2 at Analytical and Environmental Engineering Laboratory Yugantar Bharati, Namkum, Ranchi.

Understand the air monitoring and sampling technique.

To know about related equipment.

INTRODUCTION Air pollution occurs when the air contains

substances in quantities that could harm the comfort or health of humans and animals, or could damage plants and materials. These substances are called air pollutants and can be either particles, liquids or gaseous in nature (Alias M. et al, 2007).

Particulate matter and gaseous emissions of pollutant emission from industries and auto exhausts are responsible for rising discomfort, increasing airway diseases and deterioration of artistic and cultural patrimony in urban centers.

CONTI…

Ranchi is capital and one of the most important industrial cities in the state of Jharkhand. It is divided in 5 industrial zones- Tupudana industrial area, Namkum Industrial Area, Tatisilawai Industrial area, Kokar industrial area and H.E.C. with about 10 lakhs vehicles, increasing about 70000 per year in Ranchi , the city emits heavy amount of pollutants.

Thus, the ambient air quality of the city Ranchi is needed to be studied in detail as it is a major concern to care for the health of the people residing in Ranchi resulting due to pollution.

SITE:- Analytical and Environmental Engineering Laboratory Yugantar Bharati, Namkum, Ranchi.

METHODOLOGY

TRAINING SCHEDULE AND SYLLABI

Training was scheduled from 5th April 2013 to 12th

April 2013.Day 1 covered Registration, Introduction of

Equipments and their accessories, introduction to filter papers and absorbents an Review session.

Day 2 involved Preparation of Absorbents, preparation of filter papers, checklist preparation for sampling and storage and Review meeting.

Day 3 was determined as sampling date.Day 4 :- calculations/analysis of dust partials,

Analysis of gas , report preparation and review meeting.

Day 5 was for the reports submission photo session and certificate distribution.

INTRODUCTION TO EQUIPMENTS

Equipments required for the training were introduced by Mr. Sanjeev singh and Mr. mukesh singh.

Equipments required are:Respirable dust

samplerfilter paper for PM 10Filter Paper For

PM2.5Air DesecratorElectronic weight

CONTI..

SpectrophotometerLab Glass wares Gloves

RESPIRABLE DUST SAMPLER

Respirable dust sampler is an machine designed for the sampling and collection of dust and NO2 and SO2 by an attached gas manifold.

The unit separates Particulate matter by size, passing small particulate matter to filter paper and retaining the non respirable particulate matter in a cup.

It collects air at rate of 1132 lpm speed.

RESPIRABLE DUST SAMPLERModel 460 B

CONTI…..

Major parts of Respirable Dust SamplerI. Main housing :- Metallic body enclosing various

parts.II. Filter holder :- the filter holder assembly

consists hopper assembly to hold filter paper of size 8×10 inches.

III. Manometer :- The flow rate is monitored by it.IV. Time totalizer :- A time totalizer has been

provided to indicate the total time of sampling in minutes.

CONTI…….

PM 2.5 AttachmentAn attachment is added to the body which

separates and collects particulate matters of size lesser than 2.5 micron.

It has an sample cup fitted with filter paper.

CONTI……

Gas Manifold…..An Gas Manifold is attached for the sampling

of NO2 and SO2 .

Gas Manifold has glass impinger filled with absorbing solution.

It has a Rota meter which measures the Flow rate in the manifold.Generally , the flow rate is set at 1.

FILTER PAPERS

Filter Papers:- filter papers are placed in the machine to collect dust particles.

There are two types of filter papers.Filter paper made up of glass fiber of size 8×10

(Whatmann 41 GF/A) for the collection of Particulate matter of size greater than 10 µ.

Another Filter Paper is round having diameter of 47 mm made up of Teflon to collect PM 2.5.

AIR DESSICATOR

An air dessicator is used by means of moisture removal from the filter paper.

It contains silica gel which absorbs moisture and turns blue after absorbance.

SPECTROPHOTOMETER

A UV visible spectrophotometer was used for analysis of gaseous samples that is SO2 and NO2.

SAMPLING METHOD

Respirable dust sampler was set at about 3 meters height above the ground.

Both the filter papers were set at the respective sockets after moisture removal inspection and their initial weight was recorded .

Attachments were assembled on the machine.

Glass impinger of the gas manifold was filled with 30 ml each of absorbing solution for SO2 and NO2 viz. tetra chloro mercurate solution and sodium arsenate solution respectively.

CONTI…

Rota meter of gas manifold was set at 1 . Manometer was calibrated and was set up

the level by adding distilled water in the manometer.

machine was started. Time, initial flow rate of manometer and

initial volume of air at PM 2.5 attachment were recorded.

CONTI…

Machine was started at 11.00 am on 09/04/2013.

Machine was closed at 7.30 pm. Machine was disturbed 4 times which was

balanced later. Impinger of gas manifold were changed

after 8 hours.

CONTI……

After sampling, filter paper were taken out from the machine and preserved in the plastic zipper bag carefully.

Absorbing solution were taken out from the impingers and were preserved.

Next day, filter paper were weighed. SO2 and NO2 were measured.

CONTI…..MEASUREMENT OF NO2.

Take 10 ml of aliquot sample in 50 ml volumetric flask

Take 10 ml of unexposed sample in 50 ml volumetric flask 

Add 1 ml hydrogen peroxide  Add 10 ml sulfanilamide 

Add 1.4 ml NEDA 

Make up to 50 ml with distilled water 

Keep 10 minutes for reaction 

Set zero of spectrophotometer with distilled water 

Measure absorbance at 540 nm 

Calculate concentration of NO2 in µg/m3

CONTI…. MEASUREMENT OF SO2

Take 10/20 ml of aliquot sample in 25 ml vol. flask 

Take 10/20 ml of unexposed sample sample in 25 ml vol. flask 

Add 1 ml sulphamic acid, keep 10 minutes  

Add 2 ml formaldehyde  

Add 2 ml working PRA 

Make up to mark 25 ml with distilled water

Keep 30 minutes for reaction 

Set zero of spectrophotometer with distilled water 

Measure absorbance at 560 nm 

Calculate the SO2 concentration

OBSERVATIONOBSERVATION TABLE FOR PM 10

Starting time

Closing time

Filter paper code

Filter paper initial weight

Initial flow rate

Final flow rate

Filter paper final weight

11.00 AM

7.30 PM RU1 2.7610 gm

1.14 1.09 2.8140 gm

CONTI…

OBSERVATION TABLE FOR PM2.5

Starting time

Closing time

Filter paper code

Filter paper initial weight

Initial volume

Final volume

Filter paper final weight

11.00 AM

7.30 PM PT0143095

0.1525 gm

33.342 42.614 0.1530 gm

CONTI…

OBSERVATION TABLE FOR SO2

Starting time

Closing Time

Sample code

Initial flow rate

Final flow rate

11.00 AM 3.10 PM RU1- SO2 1 1

3.20 PM 7.30 PM RU2- SO2 1 1

CONTI….

OBSERVATION TABLE FOR NO2

Starting time

Closing Time

Sample code

Initial flow rate

Final flow rate

11.00 AM 3.10 PM RU1- NO2 1 1

3.20 PM 7.30 PM RU2- NO2 1 1

CALCULATIONCALCULATION OF PM 10

Time of Sampling :- 480 min.Average flow rate :- Initial flow rate+final flow

rate 2=

= 1.115 LPM

Volume of air sample :-

time of sampling × average flow rate

= 534.2 m cube

CONTI….PM 10

Dust concentration on filter paper :- 106× (Wf- Wi) vol. of air

= 106× (2.8140 – 2.7610) 535.2

= 106× 0.053 535.2

= 99.1395 µg/m3

CONTI…

Calculation of PM 2.5

Volume of air sample :- Final air volume – initial volume

= 42.614 – 33.42

= 9.272 m3

Dust concentration on filter paper :-

106× (Wf- Wi) vol. of air

= 43.9258 µg/m3

CONTI…

CONCENTRATION OF SO2

Table for absorbance and concentration of sample standard solution

Absorbance(x)Concentration(y)

0.105 0.820.122 0.960.217 1.950.328 2.960.383 3.94

CONTI…..CONCENTRATION OF SO2

Slope :- Y2 - Y1

X2 – X1

0.017 0.14

0.121

CF 8.264 ( Reciprocal of slope)

CONTI…..CONCENTRATION OF SO2

Sample code RU 1 (As – Ab)× 8.26 × 30

Va × Vt (0.015 – 0.006) × 8.264 × 30

2.435.70048 2.4

0.9297 µg/m3

CONTI..CONCENTRATION OF SO2

Sample code RU2(As – Ab)× 8.26 × 30

Va × Vt(0.026 – 0.006) × 8.264 × 30

2.4

2.06 µg/m3

CONTI….

CONCENTRATION OF NO2

Table for absorbance and concentration of sample standard solution

Absorbance(x)Concentration(y)

1.02 0.0413.93 0.0627.05 0.13410.09 0.20512.97 0.243

CONTI… CONCENTRATION OF NO2

CALCULATION OF CALIBERATION FACTOR FOR NO2

SLOPE :- Y2 – Y1

X2 – X1 0.041 – 0.062 1.02 – 3.92

0.007 CALIBERATION FACTOR 142.8571 ( Reciprocal of

Slope)

CONTI…. CONCENTRATION OF NO2

Sample code RU1

(As – Ab) × CF × Vol. Va × Vt × 0.82

(0.38 – 0.009) × 142.8571 × 300.01728 × 0.82

61.39 µg/m3

CONTI…. CONCENTRATION OF NO2

Sample code RU2

(As – Ab) × CF × Vol. Va × Vt × 0.82

(0.38 – 0.009) × 142.8571 × 300.01728 × 0.82

61.39 µg/m3

RESULTThe amount of Pollutants were recorded as

follows :- PM 10 99.1395 µg/m3 PM 2.5 43.1406 µg/m3

SO2 RU1 0.929 µg/m3

RU2 2.06 µg/m3

NO2 RU1 61.39 µg/m3

RU2 25.432 µg/m3

CONCLUSIONConcentration of pollutant at YBAEEL as

compared with CPCB norms are as below

Pollutants CPCB Standards Concentration at YBAEEL

PM 10 100 µg/m3 99.1395 µg/m3

PM 2.5 60 µg/m3 43.9258 µg/m3

SO2 80 µg/m3 RU1 0.929 µg/m3

RU2 2.06 µg/m3

NO2 80 µg/m3 RU1 61.39 µg/m3

RU2 25.432 µg/m3