Chlorine Use & Safety

Precaution

Prepared By : -

Umar Farooq Chemist “A” Chemical Section

107301@se.com.sa

umar7325@yahoo.com

SEC Shuaibah Jeddah

Saudi Arabia 1

Chlorine Usage

1. Chlorine is used in power plant for kill

microorganism in Cooling Water System .

2.Residual chlorine of 0.3-0.5 ppm is to be

maintained in the system just before the

TBS Intake and Outfall Water .

3.Chlorine existing in water as hypochlorus

and hypochlorus acid ion ( Hypochlorite )

Define as free available chlorine.

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Chlorination

HOCl <7 8> H + OCl Hypochlorous Acid

At the higher pH range as the ratio of Ocl

increase as the sterilization effect of chlorine

compound decrease.

It is practically observed that the sterilization

force of Ocl is approximately 20 time less as that

of HOCl

HOCl has significantly higher effect than Ocl

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Chlorine compound Chlorine compound used for sterilization of

microorganism

Chlorine gas Cl2

Calcium hypochlorite Ca ( Ocl )2

Sodium hypochlorite Naocl

Cl2 + H2O HOCl +HCl

Ca (Ocl )2+ H2O HOCl +Ca ( OH )2

NaOcl + H2O HOCl + NaOH

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Chlorine dioxide

5Naclo2 + 4Hcl 4Clo2 +5Nacl +2H2o

Chlorine dioxide use for potable water

disinfection

To protect drinking water from disease causing

organisms, or pathogens

Chlorine has been hailed as the savior against

cholera an acute infectious disease of the small intestine ,and

various other water-borne diseases

Chlorine dioxide

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Immediately Dangerous To Life or Health Concentrations (IDLHs)

National Institute for Occupational Safety and Health ( NIOSH )

Substance

Original IDLH Value

ppm

Revised IDLH Value

ppm

Carbon Mono Oxide 1500 1200

Chlorine 30 10

Chlorine dioxide 10 05

Chloroform 1000 500

Hydrazine 80 50

Iodine 10 2

Ammonia 500 300

Bromine 10 3

Nitrogen dioxide 50 20

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Chlorine Health Effects Table Bulletin work safe Alberta CH 067-Chemical Hazards

Chlorine Concentration ppm Health Effect

0.03-0.04 Range of odor threshold

1-3 Mid irritation of the eyes, nose and throat

3-6

Stinging or burring in the eyes, nose and

throat, headache, watering eyes, sneezing,

coughing, breathing difficulty, bloody nose.

5-10 Severe irritation of the eyes, nose and

respiratory tract

10

Immediately dangerous to life and health

( IDLH ) Concentration

10-25 May be fatal after 30 minutes of exposure.

>25

Immediate breathing difficulty, build up of fluid

in the lungs ( pulmonary edema)possibly

causing suffocation and death. Pulmonary

edema may be immediate or delayed

>1000 Fatal after a few breaths

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Safety Precaution of Chlorine

It is a very corrosive chemical

It causes burns to skin and eyes

It is harmful if ingested, inhaled

it may cause skin irritation

If it comes in contact with skin, immediately

wash the skin with plenty of water

Flush the eyes if it comes in contact with the

eyes

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Chlorine Effect On Respiratory System External Effect

1. Directly attack to cilia

2. Na & K pump damage

3. Surfactant damage

Internal Effect

1. GHS activate nephritic factor

2. Capillary damage

3. Sensory nerve

4. Interstitium

Abbreviation

Alveoli

ASC Ascorbate

Surfactant defensive system to

prevent shrinking

X Secondary Intermediate

IL8 To digest to kill

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If inhaled, the person should be

immediately removed to fresh air and

medical attention should be sought if signs

of suffocation

Eyes should be protected

Chlorine is corrosive to metallic material

To avoid corrosion should be maintain

proper dosing

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Acute Effects of Chlorine

Tickling of the nose at 0.014 to 0.054(ppm);

Tickling of the throat at 0.04 to 0.097 ppm;

Tickling of the nose and cough, stinging, or

dryness of the nose and throat at 0.06 to 0.3

ppm;

Burning of the conjunctiva and pain after 15

minutes at 0.35 to 0.72 ppm;

Discomfort ranging from ocular and respiratory

irritation to coughing, shortness of breath, and

headaches above 1.0 ppm.

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Materials Causing Immediate and

Serious Toxic Effects

Characteristics

May cause immediate

death or serious injury if

inhaled, swallowed, or

absorbed through the skin

12

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Chlorine Advantages

Economical

Traditional technology

Chlorine kill microorganism by destroying

cell wall of the microorganism with there

oxidizing forces

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Microbiology

The most

prevalent

problems

in

Cooling

water

systems

are related

to

microbiolo

gy Proteins

Phospholipids Hydrophilic groups

Hydrophobic groups

Phospholipid molecules

Glycocalyx Outer Membrane

DNA Periplasmic

Space

Flagellum Cell Membrane

Cytoplasm

Proteins

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Bacteria

Slime Formers

Iron Depositing Anaerobic

Typical Rods

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Chlorine Disadvantages

Slower kill at high pH

Consumed by ammonia, sulfides, iron, manganese, &

hydrocarbons

Volatile and easily stripped, thus high usage rates

High feed rates and residuals can cause higher

corrosion rates

Poor control (or slug treatment) leads to degradation of

water treatment compounds -- e.g. organic phosphate

and tolyltriazole

Chlorinated organics, e.g., THM’s, are toxic, regulated,

and persistent in the environment

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