Air Pollution and how to control air pollution

As we know that major sources of air pollution are vehicles and industries. Hence, for the control of air pollution we must regulate two pipes one is the silencer of the vehicle and other one is the chimney of the industry. If they both work according to the parameters of the standard emissions and emit strictly in accordance with prescribed limit then there won’t be any contamination in the air. For this purpose every individual has to take efforts at his or her own level to contribute for the air quality control.

 However, this great facility of travelling from one place to another place very comfortable should not be let free to do whatever it wants to harm the air. There should be check and balance for it and you as either owner or driver of a vehicle can contribute a lot to emit minimum and help control the air pollution. Some of the main environment friendly steps are;

➤ Make regular tuning of the vehicle.

➤Keep its engine and silencer in good condition.

➤ Get balancing of vehicles regularly.

➤ Maintain air pressure in tubes properly.

➤ Avoid using adulterated fuel.

➤ Never use or apply pressure horn.

➤ Use vehicle when very necessary.

➤ If convenient rely mostly on public transport.

Air Pollution, Sources pollutants and units.

Air Pollution is the presence of contaminants released by human activities into the earth's atmosphere having potential of causing harm to property or the precious lives of plants, animals or humans.

Sources of Air pollution 

Air pollution is caused by various types pf pollutants. Petroleum refineries release poisonous gases like sulfur dioxide, nitrogen oxides etc.

Natural Sources: Volcanos, forest fire, dust storm, oceans, plants.

Anthropogenic sources: Created by human beings.

Stationary sources

Point sources:- Industrial processing power plants, fuel combination etc.

Area Sources:- Residential heating coal gas oil, on site incineration, open burning etc.

Mobile sources 

Line sources Highway vehicle, rail road locomotive etc.

Air pollutants

Any substances occurring in the  atmosphere that may have adverse effects on humans, animals, plant life is known as an air pollutant.

Criteria Air pollutants:

Criteria air pollutants in a term used internationally to describe air pollutants that have been regulated and are used as indicators of air quality.

Based on National Ambient Air Quality Standards (NAAQS).

Primary Air pollutants 

These pollutants emitted directly from the identifiable sources are as given below

➜Oxides of sulfur (Particularly SO₂ )

➜Oxides of carbon (CO and SO₂ )

➜Oxides of nitrogen (NO_x )

➜Hydrocarbons

➜Suspended Particulate Matter (SPM)

Secondary Air Pollutants

These are produced from the chemical reaction of natural or anthropogenic primary pollutants due to their oxidation, these are more harmful.

➜Sulfuric  Acid (H₂SO₄ )

➜Ozone (O₃ )

➜Formaldehyde (HCHO)

➜Peroxy-Acyl Nitrate (PAN) etc.

Units of Measure of Air Pollutants

There are three basic units

➜Microgram per cubic metre (μց∕m3)

➜Parts per million (ppm)

➜Micron or its equivalent ( μm).

➜(μց/m3) and (ppm) are used to indicate concentration of gaseous  pollutants.

➜(μm) is used to report particle size.

Physical characteristics of water.

➤Turbidity:

Water Becomes Turbid in Appearance due to presence of suspended solids. Turbidity Depends upon fineness and concentration of particles present in water. it is measured by applying nephelometry a technique to measure level of light scattered by particles at right angle to the incident light beam. scattered light level is proportional to the concentration of particles in sample.

➔The  unit of Turbidity is NTU.

➜The IS value for drinking water is 10 to 25 NTU.

There are some other measurement of Turbidity:

➧JTU:-Jackson Turbidity units which is equal to Turbidity produced by, 1 mg SiO2 in 1 L of distilled water.

➧ FTU:-Formazin Turbidity Units in this measurement SiO2 is replaced by formazin  a chemical compound (< 1 FTU ).

➤Colour:

Dissolved organic matter from vegetation or some inorganic materials may impact colour to water. it can be measured by comparing the colour of water sample with standard glass tube containing solution of different standard colour intensities.

➜The standard unit of colour is that which is produced by 1 mg of platinum cobalt dissolved in 1 L of distilled water.

➜The IS value for treated water is 5 to 25 cobalts units.

➤Taste And Odour:

Taste and Odour  can be expressed in terms of odour intensity or threshold values. A new method is flavour Profile Analysis (FPA).

Threshold Odour Number (TON)=(A+B)/A.

 

Where, A= volume of odourous water in ml.

             B=volume of odour free water in ml required to produce a 200 ml mixture.

➜As per EPA guidelines, a maximum TON is 3 for public health service.

➤Temperature:

The increase in temperature decreases palatability (acceptable to taste) ideal temperature of water for drinking purpose is 5 to 12⁰C Above 25⁰C it is not recommended.

Raw water and their sources

Raw Water:-

Raw water is natural water found in environment such as rain water ground water and water from bodies like lakes and rivers . water in this form is considered raw.

Source of Raw water:

Surface water:

➤Ponds and lakes.

➤streams and rivers.

➤Storage reservoirs.

➤Oceans.

 

Underground water:

➤springs.

➤Infiltration wells.

➤Wells and tube wells.

 

Determination of hardness of given sample of water

DETERMINATION OF HARDNESS

OBJECTIVE: To determine the hardness of a given Sample of water

INTRODUCTION:

Hard water are generally considered to be those waters that require considerable amount of soap to produce a foam or lather and that also produce scale in hot water pipes, heaters, boilers and other unit in which the temperature of water is increased materially. Hardness are caused by multivalent metallic cat ions. Such ions are capable of reacting with soap to form precipitates and with certain anion present in the water to form scale. The principle hardness causing cat ions are the divalent calcium, magnesium, however strontium, ferrous ion, manganous ions which are normally present in trace quantities in natural water, also cause hardness. The degree of hardness of drinking water has been classified in terms of the equivalent CaCO₃ concentration as follows:

Soft	0-60 mg/l
Medium	60-120 mg/l
Hard	120-180 mg/l
Very hard	>180 mg/l

PRINCIPLE OF EDTA TITRIMETRIC METHOD:

Ethylenediamine tetra acetic acid (EDTA) and its sodium salts form a chelated soluble complex when added to a solution of certain metal cat ions. If small amount of dye such as Erichrome Black T indicator added to an aqueous solution containing calcium and magnesium ions at a pH 10.0 ± 0.1, the solution will becomes wine red. When EDTA is added as a titrant, the Ca⁺⁺ and Mg⁺⁺ divalent ions get chelated and sharp change of colour from wine red to blue which indicates complete chelation. This is the end point of titration.

REAGENTS:

1.       Buffer solution: Dissolve 16.9 gm ammonium chloride, NH₄Cl, in 143 ml conc.ammonium hydroxide, NH₄OH, add 1.25 g of magnesium salt of EDTA and dilute to 250 ml with distilled water.

2.       Standard EDTA solution: Dissolve 3.723 g of disodium salt of EDTA in 1 liter distilled water ( this solution may be standardized against standard calcium solution)

3.       Erichrome Black T indicator: Mix 0.125 g dye with 100 g hydroxylamine hydrochloride. Dissolve this mixture in 50 ml of 95% ethyl or isopropyl alcohol.

PROCEDURE:

1.       Take 50 ml of sample (or aliquot) in an Erlenmeyer flask.
2.       Add 1 or 2 ml buffer solution and three drop of Erichrome Black T indicator.
3.       Titrate with standard EDTA solution till wine red colour changes to blue. Record the volume of titrant used.

RESULT:

SAMPLE NO.	BURETTE READING		ML OF TITRANT USED
	INITIAL	FINAL
1

CALCULATION:-

Hardness (EDTA) as mg/l as CaCO₃ = [(A x B x 1000)/ml of sample ]       ML of sample = 25ml (tap water)      A= ml of titrant =         ml      B=MgCaCO₃ equivalent to 1ml of EDTA        Hardness (EDTA)= [(A x 1 x 1000)/25] mg/l as CaCO₃

measurement of pH of water in lab

MEASUREMENT OF pH

Objective :

To Estimate the pH of given sample of water by pH analysis.

SIGNIFICANCE  OF THE TEST:-

The public water supplies pH should be kept between 6.5-8.0.The water should be acidic or alkaline .If  pH value does not meet about range necessary  of pH correction is to be done .pH imparts also an important factor for biological treatment of waste water .various water treatment process like softening coagulation ,absorption, disinfection etc .pH should be kept at an optimum level .Hence pH of a water and waste water sample is required to be known.

PROCEDURE:-

Electrometer method is used to measure pH of a given sample using pH meter .The instrument should be calibrate at first using standard buffer solution known pH .The buffer pH 4.0,7.0.The electrodes are required to be    throughly  rinsed with double distilled water after every use. Before immersing the electrodes in the unknown sample the same should be dried with tissue paper of fresh cotton.The buffer reading in the pH meter must be adjusted by manual knob .The temperature of the experiment would be done at 24 degree c.After calibration of the electrodes of known pH it should be blotted with tissue paper and then to be immersed unknown sample .The direct reading given the value of pH . After calibration of the same electrodes with the known pH should be blotted with the tissue paper and to be immersed in the known sample . The direct reading will given the value of pH.

RESULT=