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Lecturer for 18-02019 25-02-2019

Pollution control experiments

• Why Environment chemistry studies are important ? life science

medical science

chemistry

multi- disciplinary science

agriculture

physics

In simpler term : it's chemical phenomena in the environment In broader tems sources study

reaction transport

effect

chemical species

Runing on effect of human activity Air

Water

Soil

lithosphere

Biosphere

Environment consists of four segments

Atmosphere

Hydrosphere

A tm o sp h e r e p r o t e c t i v e b la n k e t o f g a s e s s u r r o u n d i n g t h e e a r t h ,w h ic h s u s t a i n s l i f e o n e a r t h a n d s a v e s i t f r o m h o s tile e n v ir o n m e n t o f o u te r s p a c e .

• Air pollution • May be defined as the presence in the outdoor atmosphere of one or more contaminants or combination thereof in such quantities and of such duration as may be tend to be injurious to human , plant or animal life ,or property CO • The Atmosphere is a dynamic system ,which steadily absorbs various CO2 pollutants from natural as well as man-made sources, Gases such as : H 2S • As well as particulate matter ,such as sand and dust , are continually SO2 release through natural activities such as forest fires ,volcanic eruption NOX decay of vegetation

Classification of air-pollutants According to origin

According to chemical composition

primary pollutants

According to state of matter

directly emitted into the atmosphere as as CO,NO2,SO2 and hydrocarbon

According to origin secondary pollutants derived from the primary pollutants e.g peroxy-acyl nitrate (PAN),photo-chemical smog

Air Pollution Experiment

• Transfer the contaminated Vaseline in crucible dish for both area samples as crucible A ,B and C( Vaseline control). • Cover the crucibles then burn by furnace start with 150°C, 300°C then 400 °C for 10 min then burn at 700 to 800 °C for 30 min ash is formed in crucibles transfer the ash to 100 ml deionized water of each crucible .

• Two way to determine the trace elements 1 - High accuracy Use chemical technology instruments as Atomic absorption spectrophotometer, Trace Metals Analysis and Mass spectrophotometer 2- less accuracy titration methods.

less accuracy • Determination of lead by titration method 1- take 10 to 20 ml of sample 2- add 2 drops of 0.5 % xylenol orange indicator 3- add very diluted nitric acid (HNO₃) which turn the solution to yellow color . 4- add 0,5 gm Hexamethyl tetra-amine (C6H12N4) turns solution to red color . 5-titrate with 0.01 M Ethylenediaminetetraacetic acid ( EDTA ) Until the solution become as a result of lead nitrate ( Pb(NO3)2 ) .

• The problem associate of determination is sampling but if we take example of SO₂ is stable in atmosphere for 2-4 days ,the concertation of SO₂ sample is bubble to aqueous dilute solution of sodium titra chloro mercurate containing sulpharic acid ,it destroy any nitrogen oxide gases in air. • In whole procedure SO₂ present in air sample react with titra-chloromercurate and gas convert to non volatile complex dichloro sulphotomercurate Na₂HgCl ₂(SO₃) . •

• Contaminated air contains NO₂ is bubbled to the solution of sodium hydroxide this result to conversion nitrogen dioxide into sodium nitirte.

• Lambert's law stated that absorbance of a material sample is directly proportional to its thickness (path length)

• Beer-Lambert Law The Beer-Lambert law - is the linear relationship between absorbance and concentration of an absorbing species. The general Beer-Lambert law is usually written as: A = a(

)*b*c

where A is the measured absorbance, a( analyte concentration

) is a wavelength-dependent absorptivity coefficient, b is the path length, and c is the