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Problem Based Learning Paper – Modul 3 2012
Chlorinated Water Effects to Human Health
Group C:
Anthony Hartono 021111007
Dicky Daruanggono 021111008
Primarizka Ayunda W. 021111009
Viera Ananda Duatri S. 021111043
Endah Sih Wilujeng 021111045
Cornelia Melinda Adi S. 021111079
Nayu Nur Annisa Sholikhin 021111080
Irina Fardhani 021111117
Zahrah Musthofani 021111119
Aprillia Sonya Federika 021111118
Febria Rosana Satya Devi 021111152
Siti Atikah 021111153
Nadjwa 021111154
Faculty of Dentistry
Airlangga University 2012
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PREFACE
We are deeply praising and thankful to our Lord ALLAH SWT. Because
of His mercy, this paper can be finished as we are expected. In this paper, we
discuss about chlorinated water effects to human health, which is always a
problem for people who experienced less use of the environment with good
holistic resulting in decreased.
This paper was made in order to deepen understanding of chlorine water
issues and its effect on the human body with the hope of getting adequate health
and excellent balance.
In the process of discussing and deepening of the issue, we get the
guidance, direction, correction and advice, so we deeply thanks to:
1. Titik Bernianti, drg.,M.Kes, as our responsible person and lecturer in 3rd
Problem Based Learning.
2. Sri Yogyarti, drg., M.S as our responsible tutor and lecturer in Group I 3rd
Problem Based Learning.
We realize that there are still many shortcomings of this paper, both of
material and presentation techniques, given our lack of knowledge and
experience. So, criticism and suggestions are expected to improve this paper.
Hopefully this paper is useful for the readers.
Surabaya, 8rd of April 2012
Editor
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CONTENTS
COVER.............................................................................................................. i
PREFACE......................................................................................................... ii
CONTENTS ..................................................................................................... iii
ABSTRACT ..................................................................................................... v
CHAPTER 1 FOREWORD ........................................................................... 1
1.1 Background .............................................................................................. 1
1.2 Learning Issues ......................................................................................... 2
1.3 Purpose ..................................................................................................... 2
1.4 Benefits ..................................................................................................... 3
CHAPTER 2 THEORITICAL REVIEW...................................................... 4
2.1 Definition of Chlorine .............................................................................. 4
2.2 Characteristic of Chlorine ........................................................................ 4
2.2.1 Physical ........................................................................................ 4
2.2.2 Chemical ....................................................................................... 4
2.3 Kind of Chlorine Compound and The Applications ................................ 6
2.3.1 Hydrochloric Acid (HCl) .............................................................. 6
2.3.2 Liquid Calcium Chloride (CaCl2.................................................. 6
2.3.3 Calcium Hypochlorite (Ca(ClO)2) ............................................... 7
2.3.4 Sodium Chlorate (NaClO3) .......................................................... 7
2.3.5 Chlorine Perchlorate (Cl2O4) ...................................................... 8
2.3.6 Organochlorine Compound .......................................................... 8
2.4 Chlorinated Water..................................................................................... 9
2.4.1 Environment Factors .................................................................... 9
2.4.2 Good Effect .................................................................................. 9
2.4.3 Bad Effects ................................................................................... 11
2.4.3.1 Effect on Plants and Animals ........................................... 11
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2.4.3.2 Effect on Human Health ................................................... 12
2.4.3.2.1 Short Term Effects ......................................... 13
2.4.3.2.2 Long Term Effects …………………………… 14
2.5 Host Factors Supporting Chlorine Exposure ............................................ 21
2.5.1 Habits ............................................................................................ 21
2.5.1.1 Eating or drinking ............................................................. 21
2.5.1.2 Showering.......................................................................... 21
2.5.1.3 Washing ............................................................................ 22
2.5.2 Activities ...................................................................................... 22
2.5.2.1 Swimming ........................................................................ 22
2.5.2.2 Fishing .............................................................................. 23
2.5.2.3 Farming ............................................................................ 23
2.6 Solutions ................................................................................................... 24
2.6.1 Controlling Host Habits ................................................................ 24
2.6.2 Maintaining Chlorine Percentage in Water .................................. 24
2.6.3 Alternative Ways of Water Treatment Systems ........................... 25
2.6.3.1 Ozone Disinfectants ......................................................... 26
2.6.3.2 UV Disinfectants .............................................................. 28
2.6.3.3 Carbon Treatment Method ............................................... 31
2.6.3.4 Dechlorination .................................................................. 32
CHAPTER 3 CONCEPT MAPPING ............................................................ 37
CHAPTER 4 DISCUSSION ........................................................................... 39
CHAPTER 5 CLOSING ................................................................................. 44
5.1 Conclusion ................................................................................................. 44
5.2 Recommendation ....................................................................................... 44
REFERENCES................................................................................................. 45
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ABSTRACT
There are many factors cause available water contaminated by excessive chlorine. Geographical conditions or lack of caring clean environment can decrease fresh water supply in an area. Bad water sources require the region drinking water company to do water treatment system, called chlorination. Industrial area, using and wasting chlorine, also contaminate the ground water with excessive chlorine. Water is an essential matter for life; human habits and activities always contact with water, so it is difficult to avoid the available water perfectly. Host socio-culture aspects interact with agent (chlorine in water) and exacerbate effects of chlorinated water. Characteristic of chlorine is bound with other element easily, it can produces some harmful substances such as acid and THM that effects to human skin, hair, inhale, and teeth health. Chronic disease like cancer and heart disease is potentially happen. High intensity of chlorinated water exposure effects on short and long term diseases.
Keywords: Chlorinated water, environment, human lifestyle, effect on human health.
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CHAPTER 1
FOREWORD
1.1 BACKGROUND
Chlorine is one of elements that exists on earth and are rarely found in free
form. It is a yellow-green, noncombustible gas with a pungent, irritating odor. It is
a chemical substance, which has been used in many industries for a long time,
especially in the pulp and paper industry and drinking water treatment. It has also
been used in making dye, medicine, plastic, solvent, and dry clean. In the sector of
energy and electricity, chlorine is used in the cooling water system. Besides, it is
also used in household for disinfectant and bleach. In agriculture chlorine, in a
form of organochlorine, is also used for pesticide.
Although it has many benefits for many aspects of life, chlorine also has
adverse effects for human and environment. In industry, due to the lack of
condition of chlorine’s storage, it will lead to the leakage of chlorine gas, which
will endanger environment and health. Waste from industrial or household
activity containing chlorine has also a potential to damage environment. If it is
discharged into the waters, it will pollute the waters and its ecosystems.
Moreover, the use of chlorine in agriculture for pesticide, such as dichloro-
diphenyl-trichloroethan, can cause accumulation of residues on food chains.
Due to gas leaks, bad disposal and handling of waste containing chlorine,
it can cause high levels of chlorine in the areas. Waters can also be contaminated
by chlorine, resulting in high levels of chlorine in the water supply in the areas.
Although chlorine has a good effect as disinfectant for water treatment systems, it
can be harmful for human health. Chlorine can also easily react with many
compounds because of its character as a strong oxidator. In the chlorination
process, chlorine is also able to bind with organic compounds in water to form
organochlorine compounds, such as trihalomethanes, which are carcinogens in the
body.
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Chlorinated water itself can cause bad effect on human health, which the
level of severity depends on these three factors. They are the amount of chlorine is
exposed to, the route of exposure, and the length of time of the exposure. Human
can be exposed by chlorine through their daily activities, such as drinking
chlorinated water, using it for cooking, showering, et cetera. As a result of this
chlorine exposure, it can cause short term and long term disease.
Therefore, in this paper, we will discuss further on the relationship
between host (humans), agent (chlorine), and the environment, which influence
each other and play an integral part in the effects of the overall disease system. It
also outlines the solution to decrease high level of chlorine in the water supply,
regarding to those epidemiologic triangle.
1.2 LEARNING ISSUES
1. How is the interaction between host (humans), agent (chlorine), and the
environment in the process of diseases?
2. How is the effect of chlorine on animal and plants?
3. What are the short term and long term effects of chlorine on human
health?
4. How is the influence of human lifestyle that supports the occurrence of
chlorine exposure?
5. How to cope the excessive chlorine content in water?
1.3 PURPOSE
1. To understand the interaction between host (humans), agent (chlorine),
and the environment in the process of diseases.
2. To understand the effect of chlorine on animal and plants.
3. To understand the short term and long term effects of chlorine on human
health?
4. To understand the influence of human lifestyle that supports the
occurrence of chlorine exposure
5. To find out how to cope the excessive chlorine content in water
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1.4 BENEFITS
From these problems we can get many benefits. As we know, the
interaction between host (human), agent (chlorine), and environment play an
integral part in the effects of the overall disease system. From this we not only
gain some knowledge, but also good information to prevent and overcome the
occurrence of disease, based on the epidemiologic triangle.
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CHAPTER 2
THEORITICAL REVIEW
2.1 DEFINITION OF CHLORINE
Chlorine (Cl2) is one of the most reactive elements; it easily binds to other
elements. Because of its reactivity, chlorine gas is almost never found in nature.
Approximately 2% of the earth’s surface materials is chlorine which is mostly in
the form of sodium chloride in sea water and in natural deposits as carnallite
(KMgCl3.6H2O) and as sylvite (KCl). (The Chlorine Institute Inc., 2000)
Active volcanoes emit some chlorine, and it has been detected coming
from the decomposition of sea salt. It was first prepared in pure form by the
Swedish chemist Carl Wilhelm Scheele in 1774. Scheele heated brown stone
(manganese dioxide; MnO2) with hydrochloric acid (HCl). When these substances
are heated the bonds are broken, causing manganese chloride (MnCl2), water
(H2O) and chlorine gas (Cl2) to form. (Hasan A, 2006)
2.2 CHARACTERISTIC OF CHLORINE
2.2.1 Physical Characteristic
Chlorine is greenish-yellow diatomic gas, a liquid, or in rhombic crystals.
The pungent odor is suffocating and very irritating by inhalation. It is soluble in
water, alcohols, and alkalis, and evaporates into the air very quickly. At standard
temperature and pressure, two chlorine atoms form the diatomic molecule Cl2.
This is a yellow-green gas that has a distinctive strong odor, familiar to most from
common household bleach. The bonding between the two atoms is relatively weak
(only 242.580 ± 0.004 kJ/mol), which makes the Cl2 molecule highly reactive.
The boiling point at regular atmosphere is around −34˚C, but it can be liquefied at
room temperature with pressures above 740 kPa. (National Pollutant Inventory,
2010)
2.2.2 Chemical Characteristic
Along with fluorine, bromine, iodine, and astatine, chlorine is a member of
the halogen series that forms the group 17 (formerly VII, VIIA, or VIIB) of the
periodic table. Chlorine forms compounds with almost all of the elements to give
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compounds that are usually called chlorides. Chlorine gas reacts with most
organic compounds, and will even sluggishly support the combustion of
hydrocarbons. (Hammond, 2000)
At 25 °C and atmospheric pressure, one liter of water dissolves 3.26 g or
1.02 L of gaseous chlorine. Solutions of chlorine in water contain chlorine (Cl2),
hydrochloric acid, and hypochlorous acid:
Cl2 + H2O is in equilibrium with HCl + HClO
This conversion to the right is called disproportionation, because the
ingredient chlorine both increases and decreases in formal oxidation state. The
solubility of chlorine in water is increased if the water contains dissolved alkali
hydroxide, and in this way, chlorine bleach is produced.
Cl2 + 2OH– → ClO– + Cl– + H2O
Chlorine gas only exists in a neutral or acidic solution. (Ophardt, 2003)
Chlorinated water should be protected from sunlight. Chlorine is broken
down under the influence of sunlight. UV radiation in sunlight provides energy
which aids the break-down of underchloric acid (HOCl) molecules. First, the
water molecule (H2O) is broken down, causing electrons to be released which
reduce the chlorine atom of underchloric acid to chloride (Cl -). During this
reaction an oxygen atom is released, which will be converted into an oxygen
molecule:
2HOCl 2H+ + 2Cl- + O2
Chlorine is produced from chlorine bonds by means of electrolytic or chemical
oxidation. This is often attained by electrolysis of seawater or rock salt. The salts
are dissolved in water, forming brine. Brine can conduct a powerful direct current
in an electolytic cell. Because of this current chlorine ions (which originate from
salt dissolving in water) are transformed to chlorine atoms. Salt and water are
divided up in sodium hydroxide (NaOH) and hydrogen gas (H2) on the cathode
and chlorine gas on the anode. These cathode and anode products should be
separated, because hydrogen gas reacts with chlorine gas very aggressively.
(Agriculture and Agri-Food Canada, 2012)
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2.3 KINDS OF CHLORINE COMPOUNDS AND THE APPLICATIONS
2.3.1 Hydrochloric Acid (HCl)
Hydrochloric acid is included in a strong acid compound. Hydrochloric
acid is made by reacting chlorine and hydrogen gas at high temperatures. Gaseous
hydrochloric acid dissolved in water to obtain a solution of hydrochloric acid with
a concentration of about 36%. In industrial activities, hydrochloric acid is used as
a solvent in metal industry, chemical, food, and petroleum processing.
In the human body, hydrochloric acid is one important component of
gastric acid that acidify the gastric function. Acidity of the stomach is needed to
activate pepsinogen into pepsin enzyme as well break down protein. Hydrochloric
acid in the stomach is useful to kill the seeds of diseases carried by food.
However, the excess of hydrochloric acid in gastric fluid can damage the mucous
membranes of the stomach and even intestines. Hydrochloric acid is included in a
strong acid, which is in excessive levels can injure the walls of the stomach and
intestines. (Salocks and Kaley, 2004)
2.3.2 Liquid calcium chloride (CaCl2)
Liquid calcium chloride (CaCl2) is an ionic compound consisting of the
elements calcium (alkaline earth metal) and chlorine. It is odorless, colorless, non-
toxic solution, which is used extensively in various industries and applications
worldwide. This compound can be found most often in seawater and mineral
springs.
Ability of calcium chloride to absorb a lot of fluids is one quality that
makes it so versatile. For example, these products work much more efficient than
rock salt when it comes to clearing snow and ice from sidewalks, roads, and
highways. This is especially true at lower temperatures. There are some
drawbacks with this application, because there is some evidence that the product
may be harmful to plant life than rock salt.
Besides, calcium chloride can serve as a source of calcium ions in the
solution, not as a source of calcium ions in solution. Unlike most other calcium
compounds, calcium chloride is dissolved. These properties are useful to replace
the ions from the solution. Liquid calcium chloride can be electrolyzed to give
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calcium metal and chlorine gas. Many pools using products that contain calcium
chloride, especially in areas where there is relatively little calcium is found in the
water. The use of these products help increase water calcium levels, which in turn
minimizes the potential for corrosion of the pump. Also limit the corrosion
products with different types of swimming pool equipment, pool and
completeness of any decisions made with metal.
Calcium chloride is also used in a number of other applications. For
example, the splashing of products on the streets in a dry climate, especially the
desert, can help to minimize the amount of dust being kicked up because of
traffic. This product can be used to dry the seaweed, which helps in the production
of soda ash. It can be used as an ingredient in many kinds of plastic products, and
help thin liquid fabric softener.
Common applications include cooling brine for plants, ice and dust control
on roads. Due to its nature hygroscopic, anhydrous calcium chloride should be
stored in an airtight container tightly closed. (Flinn Scientific, Inc., 2002)
2.3.3 Calcium Hypochlorite (Ca(ClO)2)
Calcium hypochlorite is a chlorine or chemical compound that has the
chemical formula Ca(ClO)2 and available in a variety of forms, including powder,
granules, briquettes, and teblets. All these delivery forms contain solid calcium
hypochlorite with 65%-70% available chlorine. These products differ only in their
physical delivery form. Calcium hypochlorite is a white solid which is
decomposed in water, then it release oxygen and chlorine. These compounds are
not found freely in nature. Primarily, this substance is used as a water purifier or a
disinfectant. Typically used in commercial bleach, cleaning solvents, pool water
purifier, drinking water and disinfectants. As a disinfectant, chlorine can kill the
microbes. (Black, 2010)
2.3.4 Sodium Chlorate (NaClO3)
Sodium Chlorate is a chemical compound with the chemical formula
(NaClO3). When pure, it is a white crystalline powder that is readily soluble in
water. It is hygroscopic. It decomposes above 250 °C to release oxygen and leave
sodium chloride. Sodium chlorate is used in papermaking in textile industry, and
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as a cheap, if unselective, weed killer. There are many electrolytic plants for its
production, usually on the 5000-20000 ton/year. The electrolytic formation of
chlorate is dependent on complex solution chemistry coupled to a simple electron-
transfer process. In simplified terms, the overall cell reaction is:
NaCl+3H2O NaClO3+3H2
The majority of chlorate cells involve a relatively high external circulation
rate of electrolyte. The Kreb cells technology provides one example of this type of
cell. (Derek, 2010)
2.3.5 Chlorine Perchlorate (Cl2O4)
Chlorine perchlorate is the chemical compound with the formula Cl2O4.
This chlorine oxide is an asymmetric oxide, with one chlorine atom in oxidation
state +1 and the other +7, with proper formula ClOClO3. It is produced by the
photolysis of chlorine dioxide at room temperature with 436 nm ultraviolet light.
(Pletcher and Walsh, 2010)
2.3.6 Organochlorine Compound
Chlorine is used extensively in organic chemistry in substitution and
addition reactions. Chlorine often imparts many desired properties to an organic
compound, in part owing to its electro negativity. Organochlorine compounds
usually use as side products of industrial processes or as persistent pesticides.
Many important industrial products are produced via organochlorine
intermediates. Examples include polycarbonates, polyurethanes, silicones,
polytetrafluoroethylene, carboxymethyl cellulose, and propylene oxide.
Organochlorine is also used as a pesticide, such as dikloro difenil trikloro etana,
metokskhlor, aldrin, and dieldrin.
However, some of pesticide from organochlorin compound can cause
accumulation of residues on food chains, which is bad for health and environment.
In the chlorination process, chlorine is also able to bind with organic compounds
in water to form organochlorine compounds, such as trihalomethanes, which are
carcinogens in the body. (Department of Environmental Services New Hampshire,
2006)
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2.4 CHLORINATED WATER
2.4.1 Environment Factors
Chlorine contamination in the environment can be caused due to gas leak
and industry’s wastes which are not treated properly. Various industries using
chlorine in the process of its activities will generate waste containing chlorine.
Waste may contain solid, liquid, or gas. Industries using chlorine as their raw
materials, such as plastics, solvents, cement, pulp and paper, pesticides, metals,
power generation, and other chemical industries. Chlorine-containing waste is
also generated by the activity or drinking water treatment, waste of human activity
(multiple waste), and hospital waste.
Therefore, in environments, especially industrial environments which use
chlorine, are usually encountered high level of chlorine contaminating their
neighborhood. Chlorine-containing wastes can pollute the environment, including
water, resulting in high levels of chlorine in the water supply in the areas.
Chlorine pollution case ever happened in America. Kalamazoo River in Michigan,
America was polluted by waste containing PCBs (poly chlorinated byphenyls)
from paper industry.
Another cause of high level of chlorine in the water supply is the water
treatment system itself. In the process of chlorination, chlorine is used as a
disinfectant to kill microorganisms effectively. However, water treatment system,
which uses too much chlorine in the chlorination process, can also cause high
levels of chlorine in the water supply. (Hasan A, 2006)
2.4.2 Good Effect
The Use of Chlorine as Disinfectant
Chlorine is a very effective disinfectant, relatively easy to handle, cost
effective, simple to dose, measure and control, and it has a relatively good
residual effect. Chlorine disinfection is generally carried out using one of three
forms of chlorine or it can be generated on site. For small water treatment plants,
calcium hypochlorite in the form of a dry powder or proprietary tablet-type
dispenser can be used. This is more expensive than gaseous chlorine or
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hypochlorite solution, but can offer advantages in terms of convenience and low
installation costs. On a cost per mass of active chlorine basis, chlorine in the form
of a liquefied gas is the most cost effective option, but is better suited to larger,
more sophisticated works (Freese and Nozaic, 2004)
Chlorine kills pathogens such as bacteria and viruses by breaking the
chemical bonds in their molecules. Disinfectants that are used for this purpose
consist of chlorine compounds which can exchange atoms with other compounds,
such as enzymes in bacteria and other cells. When enzymes come in contact with
chlorine, one or more of the hydrogen atoms in the molecule are replaced by
chlorine. This causes the entire molecule to change shape or fall apart. When
enzymes do not function properly, a cell or bacterium will die.
When chlorine is added to water, underchloric acids form:
Cl2 + H2O HOCl + H+ + Cl-
Depending on the pH value, underchloric acid partly expires to hypochlorite ions
Cl2 + 2H2O HOCl + H3O + C-HOCl + H2O H3O+ + OCl-
This falls apart to chlorine and oxygen atoms:
OCl- Cl- + O
Underchloric acid (HOCl, which is electrically neutral) and hypochlorite
ions (OCl-, electrically negative) will form free chlorine when bound together.
This results in disinfection. Both substances have very distinctive behavior.
Underchloric acid is more reactive and is a stronger disinfectant than
hypochlorite. Underchloric acid is split into hydrochloric acid (HCl) and oxygen
atom (O). The oxygen atom is a powerful disinfectant. The disinfecting properties
of chlorine in water are based on the oxidizing power of the free oxygen atoms
and on chlorine substitution reactions.
The cell wall of pathogenic microorganisms is negatively charged by
nature. As such, it can be penetrated by the neutral underchloric acid, rather than
by the negatively charged hypochlorite ion. Underchloric acid can penetrate slime
layers, cell walls and protective layers of microorganisms and effectively kills
pathogens as a result. The microorganisms will either die or suffer from
reproductive failure.
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The effectiveness of disinfection is determined by the pH of the water.
Disinfection using chlorine will take place optimally when the pH is between 5,5
and 7,5. Underchloric acid (HOCl) reacts faster than hypochlorite ions (OCl-); it is
80-100% more effective. The level of underchloric acid will decrease when the
pH value is higher. With a pH value of 6 the level of underchloric acid is 80%,
whereas the concentration of hypochlorite ions is 20%. When the pH value is 8,
this is the other way around. When the pH value is 7,5, concentrations of
underchloric acid and hypochlorite ions are equally high (Cook, et al, 2010).
Beside the use of chlorine as disinfectants in drinking-water and
swimming pool, it can be used for household bleach and controlling bacteria and
odours in the food industry. Chlorine enters the body breathed in with
contaminated air or when consumed with contaminated food or water. It does not
remain in the body, due to its reactivity. Effects of chlorine on human health
depend on how the amount of chlorine that is present, and the length and
frequency of exposure. Effects also depend on the health of a person or condition
of the environment when exposure occurs. (Department of Community Health,
2004)
2.4.3 Bad Effects
2.4.3.1 Effect on plants and animals
Chlorine in water can affect plants which are growing under water, such as
phytoplankton. It makes the water acidic which over time can change soil pH.
Plants do not thrive as well on chlorinated as on unchlorinated water.
Phytoplankton was no recovery of photosynthetic activity when residual chlorine
had fallen to undetectable levels on it.
Chlorine dioxide (ClO2) is being evaluated for treatment of water to kill
pathogens in recirculation systems in greenhouses and in water pumped from
catchment ponds to irrigate nursery stock. The percentage of ClO2 may result in
nutrient tie-upand can affect many symptoms in plants. Phytotoxicity symptoms,
which application of ClO2 ranged from necrotic tips and margins, necrotic spots
and blotches, and death. Predominant symptoms resulting from ClO2 were
necrosis of leaf and flower tissue as spots between and across veins, and marginal
necrosis. Early symptoms could start as a yellowing of the margin or tip of leaf or
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flower. Lesions could have darkened borders. All plant species were damaged by
1000 and 2000 ppm ClO2. At 1000 and 2000 ppm ClO2, a mean toxicity rating
>4% occurred (Copes, et al, 2003).
Too much percentage of chlorine can make the pH of water decrease. The
animals can get the bad effects of chlorinated. Wild animals do not develop
atherosclerosis until they drink chlorinated water in zoos. Animals in freely life
eat their food not selected by people, they caught their food their self. So, animals
which drink chlorinated water can cause atherosclerosis.
Animals that live under water such as, frog and fish can also get the bad
effect of chlorinated water. Scientist in Minnesota propagated embryos from
healthy frogs in plain tap water. Some of the frogs had no legs or six legs, or an
eye in the middle of the throat (Hattersley JG, 2000)
Fish can tolerate chlorine extremely high, acute doses of ascorbic acid
without injury. Live channel catfish were able to withstand concentrations of
ascorbate with levels ranging from 10 to 3,000 milligrams per liter over a 24-hour
period. Additional research results are consistent with these findings.
Changes in pH are also an important concern for fish in receiving waters.
Ascorbic acid will lower pH under extreme conditions (low alkalinity water)
during flushing operations. If there are so many chlorinated water absorbed by the
fish more than 24 hour it can affected the fishes mass and make the fish being
killed (Peterka G, 2002).
2.4.3.2 Effects on human health
At least, the body has a standard how much that chlorine can enters and be
acceptable.
Normal Value Abnormal valueChloride in serum /
plasma95–110 mmol/L Less than 90 mmol/L
and greater than 115 mmol/L
Chloride in urine 110–250 mmol/24 hours
Less than 20 mmol/L and greater than 60
mmol/LChloride in sweat 5–40 mmol/LTable 1. The standard reference ranges of chloride for humans (in mmol/L)
(Bergman, 2010)
12
Chlorine in solution at the concentrations recommended is considered to
be toxicologically acceptable even for drinking-water. The WHO health-based
guideline value for chlorine in drinking-water is 5 mg/L (WHO, 2004). However,
high levels of chlorine make the water smell and give it a bad taste, which will
discourage people from drinking it. The higher level will be close to the
disinfection point and the lower level at the far extremities of the supply network.
The effects of various levels of chlorine inhalation vary with the
individuals involved. The following list is a compilation of chlorine exposure
thresholds and reported responses in humans:
Table 2. The effects of various levels of chlorine inhalation on human
health (The Chlorine Institute Inc., 2000)
Level of Chlorine Effect on Health0.2-0.4 ppm threshold of odor perception with
considerable variation among subjects (a decrease in odor perception occurs over time)
1-3 ppm mild, mucous membrane irritation, tolerated for up to one hour
5-15 ppm moderate irritation of the respiratory tract
30 ppm immediate chest pain, vomiting, dyspnea, and cough
40-60 ppm toxic pneumonitis and pulmonary edema
430 ppm lethal over 30 minutes1000 ppm fatal within a few minutes
To receive a lethal exposure, a person would have to remain near a leak source,
within a chlorine cloud, and without respiratory protection (The Chlorine Institute
Inc., 2000).
2.4.3.2.1 Short-term (acute) effects:
1. Short-term exposures to low levels of chlorine in the air rarely lead to any
long-lasting lung changes. Any exposure from smelling appropriately treated
drinking water or swimming pool water is not harmful.
2. Acute exposure to high concentrations of chlorine can lead to a build-up of
fluid in the lungs (pulmonary edema) and severe shortness of breath that could
13
lead to death if untreated. Immediately or within a few hours after breathing
chlorine gas, the lungs can become irritated, causing coughing and/or
shortness of breath. The amount of time before these symptoms occur is
dependent on the amount of chlorine to which one is exposed. (The higher the
amount one is exposed to, the shorter the amount of time before symptoms are
seen.) Exposure may result in nose and throat irritation, watery eyes,
coughing, bloody nose, nausea, vomiting, chest pain, and/or lightheadedness.
3. Drinking a chlorine solution can cause vomiting, nausea, and throat and
stomach irritation. The vomit is likely to have a chlorine smell to it.
4. Contact with chlorine gas can severely burn and irritate the eyes and skin upon
contact, possibly causing permanent damage. Liquid chlorine solutions (such
as bleach) can have vapors that are irritating to the eyes, nose and throat.
Chlorine bleach can cause irritation to exposed skin.
5. When chlorine vapor or solution comes into contact with moist tissues (such
as those found in the nose, eyes, throat, and lungs), it forms an acid
(hydrochloric acid) and can damage the exposed tissue.
6. Contact with chlorine liquid (gas kept under pressure) can cause frostbite and
chemical burns to the skin.
7. The elderly, smokers, and persons with chronic pulmonary disease may be at
greatest risk for breathing problems following acute exposure.
2.4.3.2.2 Long-term (chronic) effects:
1. Long-term exposure to low levels of chlorine gas is potentially linked to
diseases of the lung (bronchitis, shortness of breath, possible permanent
damage) and tooth corrosion.
2. Chronic exposure to chlorine also has possible link to cancers.
(Department of Community Health, 2004)
Those short-terms and long-term effects can be described as follows
according to the organ affected by exposure to chlorine
14
Skin and hair
Chlorine in shower water also has a very negative effect that is omitting
the moisture and elasticity of skin and hair. Anyone who has ever swum in
chlorinated pool can relate to the harsh effect that chlorine has on the skin and
hair. However, levels of chlorine are found higher in tap water than in the
swimming pools. (Chopra, 2006)
Chlorine destroys protein in bodies and cause adverse effects on skin and
hair. Chlorine softens the hair’s protective outer shell, its scaly cuticle. In fact,
under an electron microscope, the cuticle can be seen to have melted or worn
away. It can also damage the hair follicle itself. (Sigler, 2011)
The morphology of the cuticle cells does not reveal any fibrous
components under the transmission electron microscope (TEM). Inside the
bounding surface membrane (the outer surface) resides a layer, which has a
constant width and contains high amount of sulfur. This layer protects the cuticle
from negative effects of physical and chemical environmental factors. The next
two layers are the exocuticle and the endocuticle, vary in width. The endocuticle
firstly suffers the effect of chlorinated water and fungal invasion. Access to this
part of the cell is at the chipped border of the free cuticle edge occurring above the
skin surface as an effect of what is called “weathering”. (Forslind, et al, 2003)
Weathering is rare in children and common after puberty, particularly in
women with long hair. Natural weathering covers the cumulative effects of
climatic exposure, sunlight, wind, and water (both sea and chlorinated).
Accelerated weathering occurs with the physiochemical procedures that the owner
inflicts: oxidation by bleaching or coloring with permanent dyes. Weathered hair
may have loss of sheen, dryness or a brittle feel, increased porosity, lower
disruption point as a result of disruption of cystine linkages, decreased sulfur
content, amino acid degradation, focal disruption (trichorrhexis nodosa), or split
ends (Baron, 2005).
Taking long, hot showers is a health risk. The problem is that chloroform
and chlorine, formed in a hot steamy shower. The heat causes these toxic gases to
vaporize. The poisonous gases are then inhaled and absorbed through your skin.
15
Not only is chlorine toxic to the body, other chemicals may lurk in tap water
(Sigler, 2011).
Pool chemicals such as chlorine have a more profound effect on hair. With
prolonged exposure, chlorine can act as a bleaching agent on the hair. This is a
similar to the effects of prolonged exposure to the sun. The hair can lighten in
color and may become brittle. These effects are usually minor and are directly
proportional to the amount of time spent in the pool (Grootenhuis, 2002).
Washing in heavily chlorinated water is very harmful for skin. The
destruction of protein in bodies by chlorine can cause skin and hair become very
dry and unmanageable. Chlorine also strips the natural protective oils from skin
and hair, causing excess dryness. After clinical studies were carried out for over a
year at the Department of Dermatology, Toyama Medical Pharmaceutical
University in Japan, the researchers stated that residual chlorine in bathing water
reduces the water-holding capacity of the top layer of our skin, which results in
the skin drying out more easily, compromising the skin’s barrier and potentially
leading to infections and irritation. (Grace, 2010).
Heart Disease
There is an undeniable connection between the practice of chlorinating
water supplies and arteriosclerosis, in which a plaque composed mainly of
cholesterol builds up inside arteries, resulting eventually in heart attacks and
strokes. When chlorinated water is run through a hose or carried in a pail followed
by milk as in a dairy, very tenacious, yellowish deposits chemically similar to
arterial plaque are form; with unchlorinated water this doesn’t happen.
(Hattersley, 2000)
Cholesterol is a lipid (fatty) substance present in organism cells and
essential to life, it's a precursor for many common bio chemical compounds. But
when excess chlorine has been absorbed from drinking chlorinated water, it reacts
'with some of the cholesterol in the blood, forming the yellowish fatty deposits
that accumulate along artery walls, narrowing and hardening them, and often
causing ruptures. The result is plaque formation that causes Atherosclerosis.
Atherosclerosis is a condition in which an artery wall thickens as a result of the
16
accumulation of fatty materials such as cholesterol. It is commonly referred to as
a hardening or furring of the arteries. It is caused by the formation of
multiple plaques within the arteries.
Figure 1. Atherosclerosis (National Heart Lung and Blood Institute, 2011)
A study using chickens as test subjects, in which two groups of several
hundred birds were observed throughout their span to maturity. One group was
given water with chlorine and the other water without chlorine. The group raised
with chlorine, when autopsied, showed some level of heart or circulatory disease
in every specimen; the group without had no incidence of disease. (Hattersley,
2000)
Cancer
Chlorination of drinking water throughout the world has been recognized.
Where water is effectively chlorinated infection by waterborne diseases such as
cholera, typhoid fever and dysentery has ceased to pose a risk to public health.
However, chlorination of drinking water may produce by-products such as a
group of chemicals known as trihalomethanes (THM’s). THM’s may be formed
when chlorine reacts with natural organic matter that can be found in some water
sources. There are many forms of THM’s, such as chloroform, bromoform,
17
bromodichloromethane and dibromochloromethane. If the levels of disinfection
by-products are not controlled, they may pose a risk to health.
For several years a number of researchers around the world have been
concerned that THM’s could be a cause of some forms of cancer in the liver,
kidneys, colon, bladder, rectum and reproductive areas of the body. People living
in households with an average household water trihalomethanes (THM) level of
more than 49 micrograms per liter had double the bladder cancer risks of those
living in households where water trihalomethanes (THM) concentration was
below 8 micrograms per liter, the researchers found. (Hattersley, 2000).
THM’s can be easily absorbed by the body when (Department of Health
Western Australia, 2009):
1. water containing high levels comes into contact with the skin, or
2. if they are consumed in food prepared in water; or
3. they are inhaled during showering or bathing.
Inhale
Most high-level exposure occurs in workplaces where chlorine is used.
People may inhale chlorine by using chlorine bleach or by living near an industry
that uses chlorine. The smell from treated drinking water or swimming pools may
be irritating but isn’t usually harmful. (Wisconsin Department of Health Services,
2010)
Chlorine in swimming pools reacts with organic matter such as sweat,
urine, blood, feces, and mucus and skin cells to form more chloramines.
Chloroform risk can be 70 to 240 times higher in the air over indoor pools than
over outdoor pools. Canadian researchers found that after an hour of swimming in
a chlorinated pool, chloroform concentrations in the swimmers’ blood ranged
from 100 to 1,093 ppb.
Taking a warm shower or lounging in a tub filled with hot chlorinated
water, one inhales chloroform. Researchers recorded increases in chloroform
concentration in bathers’ lungs of about 2.7 ppb after a 10-minute shower. Worse,
warm water causes the skin to act like a sponge; and so one will absorb and inhale
18
more chlorine in a ten-minute shower than by drinking eight glasses of the same
water. This irritates the eyes, the sinuses, throat, skin and lungs, dries the hair and
scalp, worsening dandruff. It can also weaken immunity.
A window from the shower room open to the outdoors would release
chloroform from the shower room air, but to prevent its absorption through the
skin requires a showerhead that removes chlorine. (Hattersley, 2000)
Genetics
Studies in Belgium have related development of deadly malignant
melanoma to consumption of chlorinated water. Drinking and swimming in
chlorinated water can cause melanoma. Sodium hypochlorite, used in chlorination
of water for swimming pools, is mutagenic in the Ames test and other
mutagenicity tests. Redheads and blonds are disproportionately melanomaprone;
their skin contains a relative excess of pheomelanins compared to darker people.
It was reported that pollution of rivers and oceans and chlorination of swimming
pool water have led to an increase in melanoma. (Hattersley, 2000)
Long-term risks of consuming chlorinated water include excessive free
radical formation, which accelerates aging, increases vulnerability to genetic
mutation and cancer development, hinders cholesterol metabolism, and promotes
hardening of arteries. Excess free radicals created by chlorinated water also
generate dangerous toxins in the body. These have been directly linked to liver
malfunction, weakening of the immune system and pre-arteriosclerotic changes in
arteries. Excessive free radicals have been linked also to alterations of cellular
DNA. Chlorine also destroys antioxidant vitamin E, which is needed to counteract
excess oxysterol or free radicals for cardiac and anti-cancer protection.
A study also found that chlorinated water appears to increase the risk of
gastrointestinal cancer over a person’s lifetime by 50 to 100 percent. A later meta-
analysis found chlorinated water is associated each year in America with about
4,200 cases of bladder cancer and 6,500 cases of rectal cancer. Chlorine is
estimated to account for 9% of bladder cancer cases and 18% of rectal cancers.
Those cancers develop because the bladder and rectum store waste products for
periods of time. Chlorinated water is also associated with higher total risk of
19
combined cancers. Recent research has found a new hazard in chlorinated water: a
byproduct called MX. A research team from the National Public Health Institute
in Finland discovered that, by causing genetic mutations, MX initiates cancer in
laboratory animals. Also, DCA (dichloroacedic acid) in chlorinated water alters
cholesterol metabolism, changing HDL to LDL cholesterol and causes liver
cancer in laboratory animals. (Hattersley, 2000)
Teeth Erosion
Chlorine is the chemical most often used to keep swimming pools free of
bacteria. When chlorine was added into water, it produced hypochlorous acid
(HOCl) and hypochloride ion (OCl-). Therefore, extremely high levels of chlorine
in the water caused decreasing of the pH level in swimming pool water.
Meanwhile, a pH of 5.5 is considered to be the critical pH for enamel dissolution.
Dental erosion is a painful, costly, irreversible condition which can be caused by
low pH water of inadequately maintained chlorinated swimming pools.
There was a study to evaluate enamel erosion due to immersion in low pH
swimming pool water. Tooth enamel specimens were immersed in low pH
swimming pool water for a 4 hours period. Enamel loss was measured by using a
focusing method of a measuring microscope and Vickers microhardness of
enamel was measured with a microhardness tester. After immersion for 4 h, pool
water with pH of 3.85 and titratable acidity of 1.4 ml of 0.1 N NaOH eroded 5.1
μm of enamel and resulted in hardness value of enamel decreased by 23.2%,
whereas pool water with pH of 2.91 and titratable acidity of 9.5 ml of 0.1 N
NaOH eroded 31.3 μm of enamel and resulted in hardness value of enamel
decreased by 19.3%. Therefore, increase in enamel loss related to the lower pH of
water and increase in exposure time. (Chuenarrom, et al, 2010)
20
Figure 2. Erosive potential of swimming pool water with different pH on
tooth enamel over a 4 hours period. (Chuenarrom, et al, 2010)
2.5 HOST FACTORS SUPPORTING CHLORINE EXPOSURE
2.5.1 Habits (eating/drinking, showering, washing)
2.5.1.1 Eating or Drinking
If human consume chlorinated drinking water daily, it turns out people
who drink water containing chlorine are more likely to get cancer of the bladder,
rectum or colon. As for pregnant women, chlorine can cause birth defects with
abnormalities of the brain or spinal cord, low birth weight, premature birth or
even miscarriage experience. The effect of drinking chlorinated water is also the
same as using it as substance in cooking the food. (Hattersley, 2000)
2.5.1.2 Showering
Using chlorinated water for taking shower daily can also cause bad effects
on human’s health. Exposure to chlorine is through vapor inhalation and
absorption through the skin when take a bath using a shower. The warm water
from shower will open the skin pores and lead to increased absorption of chlorine
and other chemicals in that water. Inhalation of chlorine gas is very dangerous
because it can be inhaled directly into the bloodstream. (Department of
Community Health, 2004)
21
2.5.1.3 Washing
Using chlorinated water for washing may cause chlorine to contact with
skins and have almost similar effects with using it for showering. The skin does
not absorb chlorine well, but small amounts can pass through the skin when
people are exposed to chlorine gas, bleach, or come into contact with water
containing high levels of chlorine. Small amounts of chlorine can pass through the
skin into human bodies. Chlorine may irritate or burn the skin, especially moist
areas. (Department of Community Health, 2004)
2.5.2 Activities (swimming, fishing, farming)
2.5.2.1 Swimming
The present study of short term exposure to chlorine for swimmers can
cause significant immediate morbidity in most exposed people and potential lung
damage after 15–30 days affected. Swimming park or water park in a closed pace
is more dangerous than outdoors. The immediate clinical manifestation in most
people was predominantly due to the irritant effect of chlorine gas on the
lachrymal, nasal, oral, and tracheobronchial tree.
Inhalation of chlorine gas can damage both the airways and the alveolar-
capillary structures because of its solubility. At physiological pH on most
surfaces, chlorine gas combines with tissue water to form hydrochloric and
hypochlorous acids which diffuse into cells to react with the amino groups of
cytoplasm proteins, forming N-chloral derivatives.
A study found restrictive ventilator function with reduced diffusing
capacity and some obstruction in small but not in large airways 14–16 hours after
the exposure of four healthy men in a swimming pool. Lung function deficit in
asymptomatic subjects is accidentally exposed 14 days after the exposure.
Although the exact pathological change is not known, bronchiolitis
obliterans has been proposed as a lesion occurring after some toxic gas inhalation.
It has been hypothesized that low background levels of the respiratory irritants
among swimmers cause a chronic inflammatory response in the small airways that
may enhance the effects of a single acute gassing episode with a higher possibility
22
of long term squealed than in other settings. A case of asthma, persisting 2 years
after the inhalation of a mixture of sodium hypochlorite and hydrochloric acid, is
also found. (Agabiti, et al, 2001)
2.5.2.2 Fishing
On the average of water pH, about 7.8-8.0, is the ideal pH for fish to life
normally. On the higher pH and increased chlorine level up to 40% for about 28
days, fish would show the increasing frequency of operculum significantly. The
normal operculum movement is 140-143 per minutes meanwhile the fish which
are putted inside of chlorinated water will have the increase operculum movement
up to 140-153 per minutes.
That increase of operculum movement is caused by hinder diffusion of
oxygen inside of fish gills, so the absorption of the oxygen become down
dramatically. As a response fish will increase operculum movement for loaded the
amount of oxygen inside of fish body. Increased operculum movement in a long
period can affect the damage of the fish gills which impact to the death because of
the weak muscle which are used to moved the operculum.
The compound of this increased operculum cannot be known certainly
because the components of the chlorinated water are heterogeneous. But the
compound estimated as an organochlorine which have lipophilic characteristic
and reserved on the fish body easily. That organochlorine can disturb the
oxidative phosphorilation on the cell respiratory which can block the ATP
forming. The increasing of the operculum movement can cause the decrease of the
addition of fish mass. That process will happen after 16 days in chlorinated water
(Peterka, 2002).
2.5.2.3 Farming
An accidental release of approximately 15 tons of chlorine has been
described. Vegetation on farms and roadsides in the affected areas suffered from
damage from the chlorine gas. Leaves on trees were darkened and coniferous trees
were affected to the degree that the needles dropped.
Feed samples, although of generally poor quality because of difficult
harvesting conditions, showed no significant changes in pH or chloride ion
23
content when compared with samples collected elsewhere in the province. Soil
analyses showed no chlorine accumulation and no differences which could be
attributed to chlorine exposure. A limited feeding trial on three calves with forage
from the affected area showed no harmful effects in a three-week feeding period
and no observable loss of palatability.
Eggs, milk and cream samples showed no abnormalities when examined
by a taste panel. Farm livestock including pets became sick and in some cases
died following exposure. Several cattle died and post mortem lesions consisting
primarily of edema and emphysema of the lungs were observed. Pigs were sick,
but seemingly recovered in most cases. Pet animals and poultry appeared to
recover fairly quickly. Horses were more severely affected clinically and
permanent damage to the lungs may have resulted. (MacDonald, et al, 2000)
2.6 SOLUTIONS
2.6.1 Controlling Host Habit
Controlling host habit can be done by using shower filter to remove the
chlorine and soften the bathing water (Grace, 2010). The chlorine filter only
removes chlorine from the water supply, nothing else. The gaseous shower odor
from toxic chloroform was eliminated. Moreover our skin, where the hair is made,
is no longer dry and brittle (Sigler, 2011).
Here are three ways to avoid releasing chlorine gas in and around the
home:
When using a dry, chlorine-based swimming pool sanitizer, always add the
sanitizer to the pool water.
Never mix water into pool treatment chemicals.
Never mix different types of swimming pool treatment chemicals together.
Never mix household chlorine compounds (bleach, cleansers) with
ammonia or with acidbased household chemicals like toilet-bowl cleaners
2.6.2 Maintaining Chlorine Percentage in Water
The required chlorine dose can be calculated by determining the desired
residual, the volume of flow, and chlorine demand. For example, to treat 1 million
gallons per day (MGD) of water and produce a chlorine residual of 0.6 mg/L with
24
water having a 1.0 mg/L chlorine demand, the chlorine dose rate in pounds per
day would be calculated as follows:
Chlorine, pounds/day = Vol. MGD x 8.34 lbs/gal x total concentration, mg/L
= 1.0 MGD x 8.34 lbs/gal x 1.6 mg/L
= 13.3 lbs per day
Using this example, the chlorination feed equipment should be calibrated
to provide a dose of 13.3 pounds of chlorine per day. When gaseous chlorine is
used, the chlorine cylinder should be set up on a scale, and the total pounds per
day should be recorded.
When using a solution tank of calcium hypochlorite or sodium
hypochlorite, the equation above must be modified because the amount of
chemical used is not 100 percent chlorine. In the case of a hypochlorite solution
that is 65 percent available chlorine, the dose of hypochlorite needed to produce
13.3 pounds per day of chlorine would be 20.5 pounds per day (13.3 pounds per
day/0.65). The hypochlorinator must be calibrated to feed 20.5 pounds of calcium
hypochlorite per day. The contact time and dose are extremely important to
achieve good disinfection. A contact time of 30 minutes is a minimum, and the
contact time may need to be increased at low temperatures or higher pH to
achieve the same level of disinfection if the dose remains constant. A higher
chlorine dose may allow for a shorter contact time, but that may not be the best
way to optimize the disinfection process. (Lindsay L, 2005)
2.6.3 Alternative Ways of Water Treatment System
Table 3. The Advantages and Disadvantages of Disinfectants (Department of
Environmental Health Washington State, 2004)
Disinfectant Principal Advantages Principal Disadvantages
ChlorineApplied as gas or liquid (hypochlorite)
Effective for most microorganisms.
Can oxidize iron and manganese (makes them easier to remove)
Keeps a residual in distribution system
Technology well understood Relatively easy to use in a
Forms DBP when organic substances are present
Not effective against Cryptosporidium protozoa
Can cause taste and odor problem
25
hypochlorite formChloraminesFormed by combining chlorine and ammonia
Forms more stable residual than chlorine alone
Forms less DBBPs than chlorine Forms less taste and odor
causing compounds in water Technology well understood
Less effective than chlorine against microorganisms, especially viruses and protozoa
Poorly oxidizes iron and manganese
Usually requires a more powerful disinfectant for primary disinfection
Chlorine DioxideProduced by reacting sodium chlorite with chlorine or hydrochloric acid
More effective than chlorine or chloramines as disinfectant against microorganisms
Controls taste and odor better than chlorine in some cases
Forms less THMs and HAAs than chlorine
Must be produced on site Forms additional DBPs such
aschlorite and chlorate Requires daily chlorite andchlorine dioxide monitoring Costs more for equipment
andchemicals than chlorine Takes more technical skill to
use
Ozone Produced by electrical discharge through air or oxygen
Most powerful disinfectant used in drinking water treatment
More effective than chlorine dioxide
Effective against Giardia and Cryptosporidium protozoa
Must be produced on site Takes more technical skill to
use Forms bromate and other
DBPCompounds Requires bromate
monitoring Does not provide residual
protectionUltraviolet RadiationNon-chemical disinfection by using ultraviolet radiation at certain wavelengths
Effective against bacteria, Giardia, and Cryptosporidium
Does not form DBPs
Disinfection effectiveness and efficiency are affected by turbidity and dissolved substances
Less effective against certain Viruses
Technically complex, requires training to operate equipment
Does not provide residualprotection (may need
secondary disinfectant) Does not reduce DBP
formation by secondary disinfectant
26
2.6.3.1 Ozone Disinfection
Applicability
Ozone disinfection is generally used at medium to large sized plants after
at least secondary treatment. In addition to disinfection, another common use for
ozone in wastewater treatment is odor control.
Ozone disinfection is the least used method in the U.S., although this
technology has been widely accepted in Europe for decades. Ozone treatment has
the ability to achieve higher levels of disinfection than either chlorine or UV,
however, the capital costs as well as maintenance expenditures are not
competitive with available alternatives. Ozone is therefore used only sparingly,
primarily in special cases where alternatives are not effective.
Figure 3. Ozone Process Schematic Diagram (EPA, 2000)
Advantages
1. Ozone is more effective than chlorine in destroying viruses and bacteria. C
The ozonation process utilizes a short contact time (approximately 10 to 30
minutes).
2. There are no harmful residuals that need to be removed after ozonation
because ozone decomposes rapidly.
27
3. After ozonation, there is no regrowth of microorganisms, except for those
protected by the particulates in the wastewater stream.
4. Ozone is generated onsite, and thus, there are fewer safety problems
associated with shipping and handling.
5. Ozonation elevates the dissolved oxygen (DO) concentration of the effluent.
The increase in DO can eliminate the need for reaeration and also raise the
level of DO in the receiving stream.
Disadvantages
1. Low dosage may not effectively inactivate some viruses, spores, and cysts.
2. Ozonation is a more complex technology than is chlorine or UV disinfection,
requiring complicated equipment and efficient contacting systems.
3. Ozone is very reactive and corrosive, thus requiring corrosion-resistant
material such as stainless steel.
4. Ozonation is not economical for wastewater with high levels of suspended
solids (SS), biochemical oxygen demand (BOD), chemical oxygen demand,
or total organic carbon.
5. Ozone is extremely irritating and possibly toxic, so off-gases from the
contactor must be destroyed to prevent worker exposure.
6. The cost of treatment can be relatively high in capital and in power
intensiveness.
(EPA, 2000)
2.6.3.2 UV Disinfectant
Description
UV light, which continues to be a reliable means of disinfection, involves
exposing contaminated water to radiation from UV light. The treatment works
because UV light penetrates an organism’s cell walls and disrupts the cell’s
genetic material, making reproduction impossible.
A special lamp generates the radiation that creates UV light by striking an
electric arc through low-pressure mercury vapor. This lamp emits a broad
spectrum of radiation with intense peaks t UV wavelengths of 253.7 nanometers
28
(nm) and a lesser peak at 184.9 nm. Research has shown that the optimum UV
wavelength range to destroy bacteria is between 250 nm and 270 nm. At shorter
wavelengths (e.g.185 nm), UV light is powerful enough to produce ozone,
hydroxyl, and other free radicals that destroy bacteria.
The U.S. Department of Health, Education, and Welfare set guidelines for
UV light disinfection. These guidelines require a minimum dose of 16 mWs/cm2
[milliwatt seconds per square centimeter] at all points throughout the water
disinfection unit. However, the American National Standards Institute and the
National Sanitation Foundation International set the minimum UV light
requirement at 38 mWs/cm2 for class A point of use (POU) and point of entry
(POE) devices that treat visually clear water. The U.S. Environmental Protection
Agency (EPA) lists UV disinfection as an approved technology for small public
water systems. In addition, EPA is considering the following variations of
conventional UV treatment as “emerging” technologies: pulsed UV, medium-
pressure UV, and UV oxidation.
Figure 4. Closed Vessel Ultraviolet Reactor (National Drinking Water
Clearing House USA, 2000)
Advantages
1. Generally, UV is simple to install and requires little supervision, maintenance,
or space. Improved safety, minimum service time, low operation
29
2. and maintenance costs, and the absence of a chemical smell or taste in finished
water are primary factors for selecting UV technology rather than traditional
disinfection technologies.
3. UV treatment breaks down or removes some organic contaminants. UV
achieves 1-log reduction of Giardia lamblia at an intensity of 80-120
mWs/cm2, and 4-log reduction of viruses at an intensity of 90-140 mWs/cm2.
Only recently has the scientific community begun to accept UV as a highly
effective tool for Cryptosporidium control.
4. UV light disinfection does not form any significant disinfection byproducts,
nor does it cause any significant increase in assimilable organic carbon
(AOC).
5. Research has confirmed that UV effectiveness is relatively insensitive to
temperature and PH differences. In addition, researchers found that UV
application does not convert nitrates to nitrites, or bromide to bromines or
bromates.
6. Recent pilot studies show that UV-treated drinking water inhibits bacterial
growth and replication in the distribution system; however, conditions within
distribution systems, such as leaks, still require additional residual disinfection
(e.g., free chlorine).
7. The advantages of using UV, rather than chemical disinfection, include:
8. Has no known toxic or significant nontoxic byproducts;
9. Has no danger of overdosing;
10. Removes some organic contaminants;
11. Has no volatile organic compound (VOC) emissions or toxic air emissions;
12. Has no onsite smell and no smell in the final water product;
13. Requires very little contact time (seconds versus minutes for chemical
disinfection);
14. Does not require storage of hazardous material;
15. Requires minimal space for equipment and contact chamber;
16. Improves the taste of water because of some organic contaminants and
nuisance microorganisms are destroyed;
17. Does not affect minerals in water; and
30
18. Has little or no impact on the environment, except for disposing of used lamps
or obsolete equipment.
Limitations
1. Microbial and chemical characteristics are two major water quality factors that
affect the UV unit performance. Microbial characteristics of water include
type, source, age, and density. Chemical water characteristics include nitrites,
sulfites, iron, hardness, and aromatic organic levels.
2. UV radiation is not suitable for water with high levels of suspended solids,
turbidity, color, or soluble organic matter. These materials can react with UV
radiation, and reduce disinfection performance. Turbidity makes it difficult for
radiation to penetrate water.
3. Disadvantages of UV disinfection include:
4. No disinfection residual;
5. No technical database exists on how well UV systems perform for various
water quality conditions; and
6. No standardized mechanism measures, calibrates, or certifies how well
equipment works before or after installation.
7. Systems also should consider using different kinds of microbial testing.
Laboratories typically test for total coliform to judge microbiological activity
in drinking water—but coliforms are sensitive to UV light. Because of this
sensitivity, microbial tests for UV treated finished water should include a
Heterotrophic Plate Count (HPC) test. HPC microorganisms may provide a
better disinfection assessment than the UV sensitive coliforms.
(National Drinking Water Clearing House, 2000)
2.6.3.3 Carbon Treatment Method
Trace concentration of phenol from wastewater from CO & BP can be
removed by adsorption on granulated carbon. This process can be directly applied
to undiluted effluents from the ammonia still, final cooler blow down, light oil
decanter liquor and fractional ion condensate without previous biological
31
treatment. In addition, all the streams which have been bio-treated and diluted can
further be carbon treated. Therefore, carbon treatment is either an alternative or an
adjunct to biological treatment Efficiency of carbon treatment in comparison to
bio-treatment is furnished in Table 5.
Table 4. Efficiency of Carbon Treatment to bio-treatment (Sirajuddin, et al,
2008)
The secondary residuals from this treatment process are particulate and
sulphur dioxide from carbon regeneration in the reactivation of carbon by burning
off the adsorbed residuals. (Sirajuddin, et al, 2008)
2.6.3.4 Dechlorination
Applicability
Chlorination has been used widely to disinfect wastewater prior to
discharge since passage of the 1972 Federal Water Pollution Control Act
(WPCA). In the first years following the WPCA, disinfected wastewater with
significant levels of residual chlorine was routinely discharged into the receiving
waters. It became clear, however, that residual chlorine is toxic to many kinds of
aquatic life. Moreover, the reaction of chlorine with organic materials in the water
formed carcinogenic trihalomethanes and organochlorines. As a result,
dechlorination was instituted to remove residual chlorine from wastewater prior to
discharge into sensitive aquatic waters.
Dechlorination minimizes the effect of potentially toxic disinfection
byproducts by removing the free or total combined chlorine residual remaining
32
after chlorination. Typically, dechlorination is accomplished by adding sulfur
dioxide or sulfite salts (i.e., sodium sulfite, sodium bisulfite, or sodium
metabisulfite). Carbon adsorption is also an effective dechlorination method, but
is expensive compared to other methods. Carbon adsorption is usually
implemented when total dechlorination is desired. (EPA, 2000)
Advantages
1. Protects aquatic life from toxic effects of residual chlorine.
2. Prevents formation of harmful chlorinated compounds in drinking water
through reaction of residual chlorine with waterborn organic materials.
(EPA, 2000)
Disadvantages
1. Chemical dechlorination can be difficult to control when near zero levels of
residual chlorine are required.
2. Significant overdosing of sulfite can lead to sulfate formation, suppressed
dissolved oxygen content, and lower pH of the finished effluent.
(EPA, 2000)
Design Criteria
1. Chemistry of Dechlorination by Sulfonation
Sulfur dioxide (SO2) is a corrosive, nonflammable gas with a characteristic
pungent odor. At atmospheric temperature and pressure, it is a colorless vapor.
When compressed and cooled, it forms a colorless liquid. Sulfur dioxide is
supplied as liquefied gas under pressure in 100 or 150 pound containers and one-
ton cylinders. As an alternative to sulfur dioxide gas, various dry chemicals are
available which form sulfur dioxide in solution.
These include sodium sulfite (Na2SO3), sodium metabisulfite (Na2S2O5),
sodium bisulfite (NaHSO3), a 38% aqueous solution of sodium metabisulfite, and
sodium thiosulfate (Na2S2O3), among others. When dissolved in water, chlorine
hydrolyzes to form hypochlorous acid (HOCl) and hypochlorite ions (OClG)
which, taken together, are referred to as “free chlorine.” It is rarely found in
wastewater since the conditions of formation are relatively extreme. Once formed,
33
the free chlorine reacts with natural organic matter in water and wastewater to
form chlorinated organic compounds. The free chlorine also combines with
ammonia to form mono-, di-, and trichloramines in quantities dependent on the
ratio of chlorine to ammonia nitrogen.
When either sulfur dioxide or sulfite salts are dissolved in water, aqueous
sulfur compounds in the +4 oxidation state are produced, often notated S(IV). The
S(IV) species, such as the sulfite ion (SO3 -2), reacts with both free and combined
forms of chlorine, as illustrated in equations (1) and (2):
(1) SO3-2 + HOCl SO4-2 + Cl- + H+
(2) SO3-2 + NH2Cl + H20 SO4
-2 + Cl- + NH4+
Since free chlorine and inorganic chloramines react rapidly with S(IV), a
short contact time of one to five minutes is considered to be sufficient;
nevertheless, complete blending at the point of application is essential for
effective dechlorination. Proper dosage is critical to produce a nondetectable
chlorine residual. On a mass basis, 0.9 parts sulfur dioxide (or 1.46 parts NaHSO3
or 1.34 parts Na2S2O5) is required to dechlorinate 1.0 part residual chlorine. In
practice, approximately a oneto- one ratio is used. Dosing in excess must be
avoided because excess sulfite can react with dissolved oxygen (four parts sulfite
to one part oxygen) in the wastewater to produce sulfates, potentially leading to
reduced dissolved oxygen concentrations and low pH levels in the finished
effluent for high levels of overdose. Careful process control will help prevent
overdosing.
2. Equipment for gaseous sulfonation
Equipment required for gaseous sulfonation using SO2 is similar in design
to that used for chlorination, except that the materials are chosen for their
application-specific chemical resistance. The four basic components of the system
include: sufficient gas supply with automatic switch-over between cylinders; a
metering system, usually consisting of a vacuum regulator and a rotameter for
feed rate control; one or more injectors with check valves; and a residual analyzer
to measure and transmit a continuous signal proportional to the chlorine residual
in the sample stream.
34
In small concentrations, exposure to SO2 can cause eye and throat
irritation. In high concentrations, exposure can produce a suffocating effect
caused by irritation to the upper respiratory tract. Therefore, facility design should
include features for safe storage, handling, and use of sulfur dioxide. The chlorine
and sulfur dioxide cylinders should be located in separate rooms and stored in a
well ventilated, temperature-controlled area so that their temperature never drops
below 18 or exceeds 70 degrees Celsius. Gas leak detectors are necessary in the
storage area and the sulfonator area. An emergency eyewash shower and self-
contained breathing apparatus should also be provided. All personnel should
receive emergency response training. Facilities with more than 1,000 pounds of
SO2 stored on-site must abide by the Process Management Safety Standard in the
OSHA regulations.
3. Effect of Temperature on Gas Withdrawal Rate
The room temperature where the gas supply is located should be
maintained around 70 degrees F to ensure optimal gas withdrawal rates. At this
temperature, the maximum safe sulfur dioxide gas withdrawal rate is
approximately 2 lb/hr for a 150 lb container, or 25 lb/hr for a ton container.
Higher temperatures are required to achieve higher continuous gas withdrawal
rates. Strip heaters or liquid baths may be used for this purpose.
4. Injector Selection
Proper selection of the injector is critical for proper system operation. The
injector produces a vacuum that draws sulfur dioxide gas through the sulfonator.
It then mixes the gas with dilution water supply and injects the solution into the
wastewater. To properly size the injector, the back pressure on the injector at the
point of application and the water supply pressure required at the injector must be
determined. The injector can either be installed in a pipe or an open channel. As
an alternative to the typical vacuum regulator with injector system, a chemical
induction system may be used to introduce the sulfur dioxide directly as a gas.
(EPA, 2000)
Performance
35
Sulfonation has been widely considered effective for removal of chlorine
compounds in disinfected wastewater and reduction of toxicity for aquatic life.
Nevertheless, two studies have suggested that disinfected/sulfonated wastewater
poses a hazard to some sensitive aquatic species. Furthermore, one estimation of
chlorine removal efficiency is from 87 to 98 %, leaving the actual residual
chlorine following sulfonation above most regulatory limits.
Chloramines tend to be longer lived and less reactive than other
chlorinated species in wastewater. While hydrophilic organic chloramines have
been thought of as generally nontoxic, Helz and Nweke have found that the S(IV)
fraction resistant to dechlorination may be composed of hydrophobic secondary
amines and peptides, including chloramines, suggesting possible toxicity for
aquatic organisms in receiving streams. The authors note that this fraction of
S(IV)-resistant chlorine has been overlooked because the dechlorinating agent
interferes with standard analytical methods for total chlorine. Continued testing is
underway to further characterize the dechlorination-resistant fraction and its
effects on aquatic organisms. (EPA, 2000)
36
CHAPTER III
CONCEPT MAPPING
37
CHAPTER IV
DISCUSSION
Issue
A woman move to a city in which the consume of pure water is gotten
from the chlorinated water. The woman really takes care of the effect of
chlorine upon health; despite she has never sick caused by that water yet. She
also does not like the taste of water. If the woman is not severely sick cause of
the water, what kind of negative effect that may happen, if you want learn
further about the long term effect of the chlorinated water consume, what do
you need to know? Is that going trigger any problem?
It is said on the issue that the woman doesn’t like the taste, so we analyzed
that the water taste is not good; it was the sign that chlorine level is high. From
the issue, we also know the woman has a good comprehension about her health.
She knows that chlorinated water will effects badly to her body. As we know
before, chlorine is needed as disinfectant in the water. There are so many risks
that we will get if the water is not free from virus and bacteria. Chlorine is
beneficial for human for that matter, but if the level is over, then many bad effects
will appear. The exposure of high level chlorine results in bad effects on human
health.
Chlorinated water is important matter for a human. Same with the air, no
one can life without water. It also happen to the woman in the issue above, it will
be so difficult to avoid the chlorinated water perfectly. Because she still lived in
the area with chlorinated water being the one water sources. From the socio-
culture angle, there are many activities of people which is always contact water,
fishing, farming, swimming, etc. The farming activities will use the available
water in watering crops and plants, also the fishing activity will use the available
water to fill the fishpond. So, the chlorine still effects to the plants and fishes,
when the products consumed by the woman, so chlorine is effects to her
indirectly. Chlorinated water is also detected in pool, because calcium
38
hypochlorite is used as pool water purifier. Therefore, the chlorinated water still
has effects to her, as we know it will exposure to her skin, hair, teeth directly.
Chlorinated water has a conjunction with many effects that occur on
human's life such as farming and fishing. Fishing is an activity that finds some
animal which life in the water like sea, lake, river and etcetera. Besides, farming is
kind of activity that usually doing by group of people to process the area for
planted by certain plant. In this case, if chlorinated water exposure are used to
farm sector, this water can be infect the plant that are planted and watered by the
water which contaminated in the chlorine. If the plants eaten by the woman
without any good treatment of washing and cooking, it can bring the negative
effect for the woman in case, for example affect her body organ like liver, mouth
cavity, trachea, digestive system and so on. Because of the contents of chlorine
reserved by fish or animals water, it can cause the damages for the animal, and if
the fish consumed by the woman, it can damage the woman's life like the effect
that she gets if she does not washed or cooked plant.
People, who may use the chlorine water, may have effect to their hair and
skin. The chlorinated water will rob our skin and hair moisture and elasticity. And
it destroys protein in our bodies. On hair, the chlorinated water can soften the
hair's protective outer shell, its scaly cuticle and causes weathering of hair.
Weathered hair may have loss of sheen, dryness or a brittle feel, increased
porosity, lower disruption point as a result of disruption of cystine linkages,
decreased sulfur content, amino acid degradation, focal disruption (trichorrhexis
nodosa), or split ends. Beside that, with prolonged exposure, chlorine may
become a bleaching agent on hair. This is a similar to the effects of prolonged
exposure to the sun. The hair can lighten in color and may become brittle. On
skin, the chlorinated water can cause skin drying out more easily, compromising
the skin’s barrier and potentially leading to infections and irritation.
Shower filter can be used to remove the chlorine and soften the bathing
water. The chlorine filter can remove chlorine from the water supply. The gaseous
shower odor from toxic chloroform was eliminated. Moreover, our skin, where the
hair is made, is no longer dry and brittle.
39
Chlorine is an effective treatment for disinfecting water and is used in
swimming pools. It has negative effect for the human especially on teeth (dental
enamel). Exposure to excessive levels of chlorine, which cause the pH level of the
pool to fall, has been shown to cause the erosion of dental enamel. The pool water with pH 2.91 had six times higher erosive potential on enamel than the pool water with pH 3.85, indicated that an increase in enamel loss related to the lower pH of water and increasing contact time.
Low pH caused by excessive chlorination causes the enamel to erode or
wear away. Enamel is the hard protective coating of the tooth, which protects the
sensitive, softer and darker yellow dentin underneath. When the enamel is eroded,
the dentin underneath is exposed. Prevention of tooth erosion cause by low pH of
pool water starts with keeping your pool water properly balanced. Over
chlorinated pools that produce excessively elevated levels of acidity can
contribute to dental enamel erosion. A swimming pool should have a neutral pH
level between 7.2 and 7.8. Chlorine levels should be maintained between 1.0 to
3.0 ppm (parts per million). Pool chemistry should be checked regularly. It is not
recommended to allow any pool water into the mouth.
Keep consuming the chlorinated water in the long term will lead to several
diseases. One of them is atherosclerosis that will lead to heart attack and stroke. In
addition, consuming chlorinated water also increase the risk of cancer.
Chlorine content in the water that we drink later will go into the blood
vessels. Other than drinking, chlorine can also enter the body through the skin
when showering. In the blood vessels, chlorine reacts with various substances.
Among them is cholesterol. The reaction of chlorine with cholesterol makes the
cholesterol to settle / precipitate in the veins, which later will clog and interfere
the blood flow, characterized by thickening of blood vessel wall. This commonly
referred to atherosclerosis, which became the beginning of heart attack and stroke.
If atherosclerosis occurs in the blood vessels leading to the brain, it will cause
stroke. If leading to the heart it will cause heart attack.
40
Chlorinated water is also a factor increasing the risk of cancer. The
presence of compounds called Trihalomethanes (THMs) as by-product of
disinfection with chlorine compound. Trihalomethanes are formed when chlorine
reacts with the organic substances which naturally occur in raw water. The most
common THM components formed during chlorination include chloroform,
bromoform, bromodichloromethane, and chlorodibromomethane. THMs are
carcinogenic, long term consumption of water contain THMs may damage the
kidney and intestine and cause cancer.
Prevention of water that contains chlorine can be minimized if done
properly water quality treatment. In addition, important follow-up activities are
outreach efforts to educate the user or chlorinated water. Education is the process
of learning, from not knowing about the effects of chlorine to knowing, from not
being able to overcoming the idea of prevention. The purpose of this education is
to improve the health status, prevent the onset of disease and increased health
problems, maintain existing health status, maximize function and role of the
patient during the illness, and help patients and families to address health
problems on the dangers of chlorine that can enter the body humans and can be
bad for health if the life depending on chlorinated water.
In carrying out the process of water purification, one medium that can be
used is activated carbon. It’s better to use activated carbon than chlorine because
it has some interested chemical properties and physical properties, that one of
them is possibility to absorb organic and anorganic substance and being a catalyst
for some reactions. Activated carbon can be used to absorbing gases, absorbing
metal, eliminate micro pollutants like organic substance, detergen, smell, phenol,
etc.
Characteristic of activated carbon depending on the materials used,
example is coconut shell produce smooth carbon and it suits for water
purification. There are advantages from using an activated carbon for water
purifying:
a. easy to use because the water flow in carbon medium,
b. quick prosses because the carbon’s particle has a bigger size, and
41
c. carbon doesn’t mix with mud so it can be regenerated
Most of small water system use only groundwater, so they have low levels
of dissolved organic substances, DBP levels are usually not a major concern. If
water systems use hypochlorite, they can use inexpensive equipment and widely
available chemicals, and they will need no special technical skills to operate and
maintain the equipment. Most small systems find that disinfection using chlorine,
especially when added in hypochlorite form, to be the best method of disinfection
of their water supply. However, in this case the woman complained that the
water’s taste is not good, so it means it has high level of chlorine in it. As a result,
it is recommend to use dechlorination system by using sulfur dioxide which is
common in use and consider to be the safest chemical kinds for dechlorination.
This process can reduce the negative effect of chorine residual which is give bad
effect for human body.
To produce the best water quality, it needs to use ozone disinfectant,
because it is the most powerful disinfectant, but it cost high, so it can be
applicable at metropolitan city such as Jakarta, Surabaya, etc. It is not to
applicable at small city which has few professional, so it is better to use UV which
is has moderate level of disinfectant and usually combined with chlorine. The
addition of free chlorine (at a concentration of 0.25 mg/L free chlorine for
1 minute of contact time) can provide the desired 4-log inactivation of adenovirus.
42
CHAPTER V
CLOSING
5.1 CONCLUSSION
Though chlorine has a big role in disinfect the bacteria and virus from
water, the excessive chlorine is very harmful to human health. There are some
factors that correlate one and others in exacerbating the impacts of chlorine in
human health. Chlorinated water has potential to the long term and short term
diseases. However, there are some solutions that can minimize the impacts of
chlorine.
5.2 RECCOMENDATION
Migration is the most effective way to avoid the impacts perfectly for
people who live in the chlorinated water area. However, the most important is to
keep healthy life and maintain our habit especially in consuming water. We can
do some solutions above to minimize the impacts of chlorine, for example using
filter with active carbon to neutralize excessive chlorine. The region drinking
water company also must pay attention to the level of chlorine used in their water
treatment system.
43
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