ENVIRONMENTAL ENGINEERING LAB GROUP B

Zubair Talha 2007-CH-129 Muhammad Shabbir Iqbal 2007-CH-133 Muhammad Usman 2007-CH-145 Muhammad Saqlain 2007-CH-146

SUBMITTED TO :

MR. ASIF NADEEM TABISH

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CONTENTS

1. Standard test jar apparatus

2. Chemical oxygen demand apparatus

3. Dissolved oxygen meter

4. Reverse osmosis apparatus

5. Biochemical oxygen demand equipment

6. NOx measuring equipment

7. SOx measuring equipment

8. COx measuring equipment

9. Sound level meter

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STANDARD TEST JAR APPARATUS

Jar Test Apparatus allows efficient and economical flocculation matter and collides in general and also has

been specially designed for use in water treatments to correctly estimate the dosing of alum and such

other coagulants for treatment of Water sewage and floc formation test in Water Treatment plants.

OBJECTIVE:

‘It is used to remove the turbidity in the given sample’. Turbidity appears due to the presence of suspended

material in the sample. Light falling on the sample is scattered due to this matter and because of this

scattering, cloudiness appears. This cloudiness is referred to as turbidity.

THEORY:

The basic principal behind all

activated sludge type wastewater

treatment processes is the growth

of microorganisms that colonize

into settleable floc particles. Under

ideal conditions these floc particles

are allowed to settle forming a

sludge blanket and leaving a clear

supernatant free of organic

material and suspended solids.

Floc particles can vary greatly in

size and density due to a variety of

treatment factors. Mixed liquor floc

particles can be subjected to a

wide range of environmental,

mechanical and chemical factors which can influence their settleability.

EQUIPMENT:

The equipment is provided with the turbidity meter that measures the initial and final turbidity of the

samples before and after adding the required dosage of flocculent and coagulant. There is control console

with the provision of setting the desired RPM and time.

Jar testing is a method of simulating a full-scale water treatment process, providing system operators a

reasonable idea of the way a treatment chemical will behave and operate with a particular type of raw

water. Because it mimics full-scale operation, system operators can use jar testing to help determine which

treatment chemical will work best with their system’s raw water. Jar testing entails adjusting the amount of

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treatment chemicals and the sequence in which they are added to samples of raw water held in jars or

beakers. The sample is then stirred so that the formation, development, and settlement of floc can be

watched just as it would be in the full-scale Treatment plant. (Floc forms when treatment chemicals react

with material in the raw water and clump together.)

APPLICATIONS:

Such equipment is widely used in the water treatment process to determine proper dosages of coagulants.

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CHEMICAL OXYGEN DEMAND EQUIPMENT

DEFINITION:

Chemical Oxygen Demand (COD) is defined as the quantity of a specified oxidant that reacts with a

sample under controlled conditions. Total organic carbon (TOC) = COD + BOD.

EXPLANITION:

In environmental chemistry, the chemical oxygen demand (COD) test is commonly used to indirectly

measure the amount of organic compounds in water. Most applications of COD determine the amount of

organic pollutants found in surface water (e.g. lakes and rivers), making COD a useful measure of water

quality. It is expressed in milligrams per liter (mg/L), which indicates the mass of oxygen consumed per

liter of solution. COD is often measured as a rapid indicator of organic pollutant in water. It is normally

measured in both municipal and industrial wastewater treatment plants and gives an indication of the

efficiency of the treatment process. The efficiency of the treatment process is normally expressed as COD

Removal, measured as a percentage of the organic matter purified during the cycle. Many governments

impose strict regulations regarding the maximum chemical oxygen demand allowed in wastewater before

they can be returned to the environment. For example, in Switzerland, a maximum oxygen demand

between 200 and 1000 mg/L must be reached before wastewater or industrial water can be returned to the

environment.

COD EQUIPMENT:

Chemical oxygen demand (COD) equipment is used to find the COD of the different samples. COD is the

water quality parameter. COD value indicates the amount of oxygen that is required for the chemical

oxidation of organic matter present in the sample and indirectly the amount of organic matter. Apparatus

consist of a distillation flask, a reflux condenser for entrapping the volatile materials, cylinders for

measuring volumes and chemicals.

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DISSOLVED OXYGEN METER

DISSOLVED OXYGEN:

D.O is the molecular or the gaseous oxygen present in water. One unit of measure of dissolved oxygen in

water is parts per million (ppm), which is the number of oxygen (O2) molecules per million total molecules

in a sample. Calculating the percent saturation is another way to analyze dissolved oxygen levels. Percent

saturation is the measured dissolved oxygen level divided by the greatest amount of oxygen that the water

can hold at that particular temperature and atmospheric pressure, then multiplied by 100.

PURPOSE OF D.O METER:

Dissolved oxygen (D.O) meter is used to find the amount of dissolved oxygen in the given sample of water.

It is required for the survival of living beings. D.O concentration is very important to check whether the

given water sample is perfect for the given use or not. e.g. for living species under water, the water

becomes dangerous for their lives, if D.O super-saturation is above 140%. The meter can be calibrated to

give the desired readings for the pressure in mmHg, absolute pressure in hPa, %oxygen saturation and

oxygen concentration in mg/l.

SOURCES OF DISSOLVED OXYGEN:

The two main sources of dissolved oxygen in stream water are the atmosphere and aquatic plants.

Atmospheric oxygen is mixed into stream water as waves crash along the riffles. Aquatic plants introduce

oxygen into stream water as a byproduct of photosynthesis. The amount of oxygen that can dissolve in

water is limited by physical conditions such as temperature and atmospheric pressure.

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The above graph shows the maximum amount of

oxygen that can be dissolved in water at various

temperatures. Assuming a constant atmospheric

pressure, water of low temperatures can hold

more oxygen than water of high temperatures.

Fish growth and activity usually require 5-6 ppm

of dissolved oxygen. Dissolved oxygen levels

below 3 ppm are stressful to most aquatic

organisms. Levels below 2 ppm will not support

fish at all.

LOW DISSOLVED OXYGEN:

Low dissolved oxygen levels can be the result of elevated temperature and thus the inability of the water to

hold the available oxygen. Low dissolved oxygen levels can also indicate an excessive demand on the

oxygen in the system. Some pollutants such as acid mine drainage produce direct chemical demands on

oxygen in the water for certain oxidation-reduction reactions.

USES OF DISSOLVED OXYGEN METER

Some of the industrial uses of a dissolved oxygen meter are:

Analysis of boiler feed water for industries

Waste water treatment plants

Pollution control in rivers and lakes

Ionic concentration measurement for pharmaceutical companies

Analysis of drinking water

The typical features that should be available with the Oxygen Meter that you are purchasing are:

Self Calibration

Event Triggers

Battery Packs

Filters

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REVERSE OSMOSIS EQUIPMENT

PURPOSE OF EQUIPMENT:

Reverse osmosis equipment is used for the treatment of water. It can reduce the organics, Inorganics,

bacteria and particles found in contaminated drinking water to tolerable levels at lower energy costs. It can

accomplish the removal of contaminates to the desired degree of purity. R.O equipment is provided with

the sediment filter, activated carbon, water softener, R.O membrane, and mercury vapor lamp and

conductivity meter.

RO TECHNOLOGY:

RO technology is used to remove dissolved impurities from water through the use of a semi-permeable

membrane. RO involves the reversal of flow through a membrane from a high salinity, or concentrated,

solution to the high purity, or "permeate", stream on the opposite side of the membrane. Pressure is used

as the driving force for the separation. The applied pressure must be in excess of the osmotic pressure of

the dissolved contaminants to allow flow across the membrane. In the normal osmosis process the solvent

naturally moves from an area of low solute concentration, through a membrane, to an area of high solute

concentration. The movement of a pure solvent to equalize solute concentrations on each side of a

membrane generates a pressure and this is the "osmotic pressure." Applying an external pressure to

reverse the natural flow of pure solvent, thus, is reverse osmosis. The process is similar to membrane

filtration. However, there are key differences between reverse osmosis and filtration. The predominant

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removal mechanism in membrane filtration is straining, or size exclusion. Reverse osmosis, however,

involves a diffusive mechanism so that separation efficiency is dependent on solute concentration,

pressure.

APPLICATIONS:

Drinking water purification

Water and wastewater purification

Food Industry

Maple Syrup Production

Desalination

How reverse osmosis works

DISADVANTAGES OF REVERSE OSMOSIS UNITS:

RO units use a lot of water. They recover only 5 to 15 percent of the water entering the system. The

remainder is discharged as waste water. Because waste water carries with it the rejected contaminants,

methods to re-cover this water are not practical for household systems. Waste water is typically connected

to the house drains and will add to the load on the household septic system.

The water supply entering the RO unit should be bacteriologically safe. RO units will remove virtually all

microorganisms but they are not recommended for that use because of the possibility of contamination

through pinhole leaks or deterioration due to bacterial growth. Water softeners are commonly used in

advance of the RO system.

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BIOLOGICAL OXYGEN DEMAND

BACKGROUND INFORMATION

Microorganisms such as bacteria are

responsible for decomposing organic waste.

When organic matter such as dead plants,

leaves, grass clippings, manure, sewage, or

even food waste is present in a water supply,

the bacteria will begin the process of breaking

down this waste. When this happens, much of

the available dissolved oxygen is consumed

by aerobic bacteria, robbing other aquatic

organisms of the oxygen they need to live.

Biochemical oxygen demand or BOD is a chemical procedure for determining the amount of dissolved

oxygen needed by aerobic biological organisms in a body of water to break down organic material present

in a given water sample at certain temperature over a specific time period. It is not a precise quantitative

test, although it is widely used as an indication of the organic quality of water. It is most commonly

expressed in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20 °C and

is often used as a robust surrogate of the degree of organic pollution of water.

METHODS FOR THE MEASUREMENT OF BOD

DILUTION METHOD

To ensure that all other conditions are equal, a very small amount of micro-organism seed is added to

each sample being tested. This seed is typically generated by diluting activated sludge with de-ionized

water. The BOD test is carried out by diluting the sample with oxygen saturated de-ionized water,

inoculating it with a fixed aliquot of seed, measuring the dissolved oxygen (DO) and then sealing the

sample to prevent further oxygen dissolving in. The sample is kept at 20 °C in the dark to prevent

photosynthesis (and thereby the addition of oxygen) for five days, and the dissolved oxygen is measured

again. The difference between the final DO and initial DO is the BOD. The loss of dissolved oxygen in the

sample, once corrections have been made for the degree of dilution, is called the BOD5.

BOD can be calculated by:

Undiluted: Initial DO - Final DO = BOD

Diluted: ((Initial DO - Final DO)- BOD of Seed) x Dilution Factor

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BOD is similar in function to chemical oxygen demand (COD), in that both measure the amount of organic

compounds in water.

MANOMETRIC METHOD

This method is limited to the measurement of the oxygen consumption due only to carbonaceous

oxidation. Ammonia oxidation is inhibited. The sample is kept in a sealed container fitted with a pressure

sensor. A substance that absorbs carbon dioxide (typically lithium hydroxide) is added in the container

above the sample level. The sample is stored in conditions identical to the dilution method. Oxygen is

consumed and, as ammonia oxidation is inhibited, carbon dioxide is released. The total amount of gas,

and thus the pressure, decreases because carbon dioxide is absorbed. From the drop of pressure, the

sensor electronics computes and displays the consumed quantity of oxygen.

The main advantages of this method compared to the dilution method are:

Simplicity: no dilution of sample required, no seeding, no blank sample.

Direct reading of BOD value.

Continuous display of BOD value at the current incubation time.

IMPORTANCES OF BOD

The test for Biochemical Oxygen Demand is especially important in

waste water treatment,

food manufacturing

filtration facilities where the concentration of oxygen is crucial to the overall process and end

products. High concentrations of dissolved oxygen (DO) predict that oxygen uptake by

microorganisms is low along with the required break down of nutrient sources in the medium

(sample).

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COX MEASURING APPARATUS

SOURCES OF CO2 AND CO

The largest source of CO2 emissions globally is the combustion of fossil fuels such as coal, oil and gas in

power plants, automobiles, industrial facilities and other sources. A number of specialized industrial

production processes and product uses such as mineral production, metal production and the use of

petroleum-based products can also lead to CO2 emissions. Carbon monoxide is present in small amounts

in the atmosphere, chiefly as a product of volcanic activity but also from natural and man-made fires (such

as forest and bushfires, burning of crop residues, and sugarcane fire-cleaning). The burning of fossil fuels

also contributes to carbon monoxide production.

MEASURING APPARATUS

Measurements are based on the absorption of

infrared radiation by carbon monoxide (CO) in a

non-dispersive photometer. Infrared energy from a

source is passed through a cell containing the gas

sample to be analyzed, and the quantitative

absorption of energy by CO in the sample cell is

measured by a suitable detector. The photometer

is sensitized to CO by employing CO gas in either

the detector or in a filter cell in the optical path,

thereby limiting the measured absorption to one or

more of the characteristic wavelengths at which

CO strongly absorbs. Optical filters or other means may also be used to limit sensitivity of the photometer

to a narrow band of interest. Various schemes may be used to provide a suitable zero reference for the

photometer. The measured absorption is converted to an electrical output signal, which is related to the

concentration of CO in the measurement cell.

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NOX MEASURING APPARATUS

GERNAL DESCRIPTION OF NOx:

NOx is a generic term for the mono-nitrogen oxides NO and NO2 (nitric oxide and nitrogen dioxide). They

are produced from the reaction of nitrogen and oxygen gases in the air during combustion, especially at

high temperatures. In areas of high motor vehicle traffic, such as in large cities, the amount of nitrogen

oxides emitted into the atmosphere as air pollution can be quite significant. In atmospheric chemistry, the

term means the total concentration of NO and NO2. NOx react to form smog and acid rain. NOx are also

central to the formation of tropospheric ozone.NOx should not be confused with nitrous oxide (N2O), which

is a greenhouse gas and has many uses as an oxidizer, an anesthetic, and a food additive

FORMATION AND REACTION

The oxygen and nitrogen do not react at ambient temperatures. But at high temperatures, they have an

endothermic reaction producing various oxides of nitrogen. Such temperatures arise inside an internal

combustion engine, combustion of a mixture of air and fuel. In atmospheric chemistry, the term NOx means

the total concentration of NO and NO2. During daylight, these concentrations are in equilibrium; the ratio

NO/NO2 is determined by the intensity of sunshine (which converts NO2 to NO) and the concentration of

ozone (which reacts with NO to again form NO2).

In the presence of excess oxygen (O2), nitric oxide (NO) reacts with the oxygen to form nitrogen dioxide

(NO2). When NOx and volatile organic compounds (VOCs) react in the presence of sunlight, they form

photochemical smog, a significant form of air pollution

SOURCES OF NOx

Nitric oxide is produced during thunderstorms due to the extreme heat of lightning, and is caused by the

splitting of nitrogen molecules. This can result in the production of acid rain, if nitrous oxide forms

compounds with the water molecules in precipitation, thus creating acid rain.

BIOGENIC SOURCES

Agricultural fertilization and the use of nitrogen fixing plants also contribute to atmospheric NOx, by

promoting nitrogen fixation by microorganisms.

INDUSTRIAL SOURCES

The three primary sources of NOx in combustion processes:

thermal NOx

fuel NOx

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MEASURING APPARTUS

It measure the concentration of NOx present in given air sample.it works on the principle of

chemilluminescence,there is a screen that display the continuous readings for the concentration of

NO,NO2 and NOx The chemiluminescence method for gas analysis of oxides of nitrogen relies on the

measurement of light produced by the gas-phase titration of nitric oxide and ozone

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SOx MEASURING APPARATUS

GERNAL DESCRIPTION

SOX is referred to SO, SO2 and SO3. Sulphur monoxide is a chemical compound with formulaSO. It is an

unstable species only found in the gas phase where it is in equilibrium with a dimeric form, S2O2

(sometimes called disulphur dioxide). Sulphur monoxide has been detected around Io, one of Jupiter's

moons, both in the atmosphere and in the plasmatorus. It has also been found in the atmosphere of

Venus, in the Hale-Bopp comet and in interstellar space.

Sulphur dioxide is the chemical compound with the formula SO2. It is produced by volcanoes and in

various industrial processes. Since coal and petroleum often contain sulphur compounds, their combustion

generates sulphur dioxide. Further oxidation of SO2, usually in the presence of a catalyst such as NO2,

forms H2SO4, and thus acid rain. This is one of the causes for concern over the environmental impact of

the use of these fuels as power sources. Sulphur trioxide is the chemical compound with the formula SO3.

In the gaseous form, this species is a significant pollutant, being the primary agent in acid rain. It is

prepared on massive scales as a precursor to sulphuric acid. Hydrogen sulphide is the chemical

compound with the formulaH2S. This colorless, toxic and flammable gas is partially responsible for the foul

odor of rotten eggs and flatulence.

It often results from thebacterial break down of sulphates in organic matter in the absence of oxygen, such

as in swamps and sewers (anaerobic digestion). It also occurs in volcanic gases, natural gas and some

well waters. The odor of H2S is commonly misattributed to elemental sulphur, which is in fact odorless.

Hydrogen sulfide has numerous names, some of which are archaic. SOX and H2S are measured by the

amount of ultra violet light that is absorbed by the air. The more the SOXis present more UV light would be

absorbed.

SOURCE OF THESE GASES:

SOx gases are formed when fuel containing sulfur, such as coal and oil, is burned, and when gasoline is

extracted from oil, or metals are extracted from ore. SO2 dissolves in water vapor to form acid, and

interacts with other gases and particles in the air to form sulfates and other products that can be harmful to

people and their environment.

EFFECTS OF SOx

Sulfur Oxides contribute to the formation of acid rain, which damages trees and makes soils, lakes, and

streams acidic. It contributes to the formation of atmospheric particles that cause visibility impairment.

Sulfur oxide can be transported over long distance and the pollutants formed can be transported over long

distances and deposited far from the point of origin. This means that problems with this pollutant are not

confined to areas where it is emitted.

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SO2 itself can cause adverse effects on respiratory systems of humans and animals, and damage to

vegetation. When dissolved by water vapour to form acids it can again have adverse effects on the

respiratory systems of humans and animals, and it can cause damage to vegetation, buildings and

materials, and contribute to acidification of aquatic and terrestrial ecosystems. When transformed into

sulphate particles that are subsequently deposited on aquatic and terrestrial ecosystems, acidification can

result, and when sulphate is combined with other compounds in the atmosphere, such as ammonia, it

becomes an important contributor to the secondary formation of respirableparticulate matter (PM2.5). PM2.5

is known to have harmful effects on human health and the environment, and contribute to visibility

impairment and regional haze.

APPARATUS

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SOUND LEVEL METER

Sound level meters measure sound pressure level and are commonly used in noise pollution studies for

the quantification of almost any noise, but especially for industrial, environmental and aircraft noise.

However, the reading given by a sound level meter does not correlate well to human-perceived loudness;

for this a loudness meter is needed.

EXPONENTIALLY AVERAGING SOUND LEVEL METER

The standard sound level meter is more correctly called an exponentially averaging sound level meter as

the AC signal from the microphone is converted to DC by a root-mean-square (RMS) circuit and thus it

must have a time-constant of integration; today referred to as time-weighting. The output of the RMS circuit

is linear in voltage and is passed through a logarithmic circuit to give a readout linear in decibels (dB). This

is 20 times the base 10 logarithm of the ratio of a given root-mean-square sound pressure to the reference

sound pressure. Root-mean-square sound pressure being obtained with a standard frequency weighting

and standard time weighting. The reference pressure is set by International agreement to be 20

micropascals for airborne sound. It follows that the decibel is in a sense not a unit, it is simply a

dimensionless ratio—in this case the ratio of two pressures.

LAT or Leq: EQUIVALENT CONTINUOUS SOUND LEVEL

Sound exposure level in decibels is not much used in industrial noise measurement. Instead, the time-

averaged value is used. This is the time average sound level or as it is usually called the 'equivalent

continuous sound level' has the formal symbol LAT These abbreviation mainly, follow the formal ISO

acoustic definitions. However, for mainly historical reasons, LAT is commonly referred to as Leq.

SOUND LEVEL METERS CLASSES

Sound level meters are divided into two classes, called 'types' in previous standards. The two classes have

the same design centre goals but the tolerances differ. Class 1 instruments have a wider frequency range

and a tighter tolerance than a similar, lower cost, Class 2 unit. This applies to both the sound level meter

itself as well as the associated calibrator. Most national standards permit the use of "at least a Class 2

instrument" and for many measurements, there is little practical point in using a Class 1 unit; these are

best employed for research and law enforcement.

ANSI/IEC: THE ATLANTIC DIVIDE

Sound level meters are also divided into two types in "the Atlantic divide". Sound level meters meeting the

USA American National Standards Institute (ANSI) specifications cannot usually meet the corresponding

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International Electrotechnical Commission (IEC) specifications at the same time, as the ANSI standard

describes instruments that are calibrated to a randomly incident wave, i.e. a diffuse sound field, while

internationally meters are calibrated to a free field wave, that is sound coming from a single direction.

ORGANIZATIONS

The United Kingdom professional body for acoustics

The International Institute for Noise control

The home page of the IEC standards body

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REFERENCES

1. ‘EnvironmentalEngineering’ ,

http://www.uet.edu.pk/export/sites/UETWebPortal/faculties/facultiesinfo/chemical/Labs/Environme

ntalEngineering.pdf

2. ‘Chemical_oxygen_demand’ , http://en.wikipedia.org/wiki/Chemical_oxygen_demand

3. ‘define:Chemical+oxygen+demand’ ,

http://www.google.com.pk/search?hl=en&biw=1024&bih=578&defl=en&q=define:Chemical+oxyge

n+demand&sa=X&ei=UZNtTb6KDJSq8APC962MBQ&ved=0CBsQkAE

4. ‘WQassess3f’,

http://www.cotf.edu/ete/modules/waterq3/WQassess3f.html

5. ‘Reverse_osmosis’ ,

http://en.wikipedia.org/wiki/Reverse_osmosis

6. ‘ae1047w’ , http://www.ag.ndsu.edu/pubs/h2oqual/watsys/ae1047w.htm

7. Komorn A. & Luquet P. Methode de description objective d'un environnement acoustique LNE report 1979

8. Wallis A. D. From Mahogany to Computers Proceedings Euronoise, London. Plenary Paper. Sept 1992.

9. Beranek, Leo L, Acoustics (1993) Acoustical Society of America. ISBN 0-88318-494-X