INTRODUCTION Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans, aquifers and groundwater). Water pollution occurs when pollutants are directly or indirectly discharged into water bodies without adequate treatment to remove harmful compounds. Water pollution affects plants and organisms living in these bodies of water. In almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities. The addition of harmful chemicals to natural water. Sources of water pollution in the United States include industrial waste, run-off from fields treated with chemical fertilizers, and run- off from areas that have been mined. Water pollution is a major global problem which requires ongoing evaluation and revision of water resource policy at all levels (international down to individual aquifers and wells). It has been suggested that it is the leading worldwide
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INTRODUCTION
Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans, aquifers and
groundwater). Water pollution occurs when pollutants are directly or indirectly discharged into
water bodies without adequate treatment to remove harmful compounds.
Water pollution affects plants and organisms living in these bodies of water. In almost all cases
the effect is damaging not only to individual species and populations, but also to the natural
biological communities.
The addition of harmful chemicals to natural water. Sources of water pollution in the United
States include industrial waste, run-off from fields treated with chemical fertilizers, and run-off
from areas that have been mined.
Water pollution is a major global problem which requires ongoing evaluation and revision
of water resource policy at all levels (international down to individual aquifers and wells). It has
been suggested that it is the leading worldwide cause of deaths and diseases,and that it accounts
for the deaths of more than 14,000 people daily. An estimated 700 million Indians have no
access to a proper toilet, and 1,000 Indian children die of diarrheal sickness every day. Some
90% of China's cities suffer from some degree of water pollution,and nearly 500 million people
lack access to safe drinking water. In addition to the acute problems of water pollution in
developing countries, developed countries continue to struggle with pollution problems as well.
In the most recent national report on water quality in the United States, 45 percent of assessed
stream miles, 47 percent of assessed lake acres, and 32 percent of assessed bays and estuarine
square miles were classified as polluted.
Water is typically referred to as polluted when it is impaired by anthropogenic contaminants and
either does not support a human use, such as drinking water, and/or undergoes a marked shift in
its ability to support its constituent biotic communities, such as fish. Natural phenomena such as
volcanoes, algae blooms, storms, and earthquakes also cause major changes in water quality and
the ecological status of water.
SOURCES OF WATER POLLUTION
During recent years, there has been an increasing awareness of, and concern about, water
pollution all over the world, and new approaches towards achieving sustainable exploitation of
water resources have been developed internationally.
It is widely agreed that a properly developed policy framework is a key element in the sound
management of water resources. With the rapid growth of population, industrialization and
urbanisation, environmental pollution has greatly increased. The major sources of water
pollution arise from many activities.
They include domestic, industrial and agricultural wastes. Domestic waste contains pathogenic
organisms which are responsible for the spread of communicable diseases such as cholera,
typhoid, dysentery and other gastrointestinal diseases.
These wastes also contain materials which are responsible for obnoxious conditions and
irreparable damage to aesthetics of land and water environment. Industrial wastes contain a wide
variety of organic substances and minerals including cyanides, arsenic, mercury, and cadmium,
carcinogens which are toxic to human and plant life. Agricultural drainage carries dangerous
pesticide residues and unused fertilizer ingredients.
The term 'water pollution' can be briefly defined as any alteration in physical, chemical or
biological properties of water, rendering the water harmful to public health and safety. For
convenience, the sources of contamination of water can be classified as natural and
anthropogenic (man-made).
NATURAL SOURCES
Important natural sources are surface run-off, seepage from ground water and swamp drainage.
In urban areas, rain water is reported to be acidic. This is due to reaction between water droplets
and atmospheric oxides of sulphur and nitrogen. The atmospheric sulphur dioxide (S02) is
always accompanied by a little amount of sulphur tri-oxide (S03) which, under humid condition,
reacts with water vapour to form sulphuric acid thus causing acid rain. The chemical reaction
involved in this process is represented as follows:
Leachates from animal excreta, decaying bodies of animals and plants, solid waste landfill sites
and the decay of large quantities of organic matter in swamps or deep ponds also introduce
appreciable amounts of soluble organics and microorganisms which in turn contaminate the
adjacent ground water.
ANTHROPOGENIC SOURCES
Anthropogenic sources are the result of industrial, domestic, agricultural and mining activities of
man.
INDUSTRIAL SOURCES
Nowadays, industries are the major contributors of water pollution. Water is an essential raw
material in almost all manufacturing plants. In India, industries such as tanneries, sugar mills,
pulp and paper mills, distilleries, oil refineries, etc. generate a large quantity of wastewater which
is discharged into natural waterways either without treatment or after partial treatment. The
characteristics of industrial wastewater depend primarily on the type of industry and the
chemicals used in various processes.
DOMESTIC SOURCES
In urban areas, municipal sewage is discharged into the nearby canal, thus polluting the canal
and also deteriorating the ground water. Municipal sewage includes wastewater from houses,
commercial buildings and institutions. The important pollutants present are biodegradable
organic matter, coliforms and pathogens.
AGRICULTURAL SOURCES
Pollutants discharged into water courses due to agricultural activities include:
1. Soil and silt removed by erosion
2. Agricultural run-off
3. Synthetic fertilizers, herbicides and insecticides
4. Plant residue.
Receiving water bodies get fertilised with nutrients, thus resulting in Eutrophication. Some
common insecticides in use are chlorinated hydrocarbons such as DDT (dichloro diphenyl
trichloroethane), aldrin, heptachlor, PCBs (polychlorinated biphenyl) etc. Most of the chlorinated
hydrocarbons are persistent to degradation and hence remain in the environment for a very long
time. Indiscriminate use of insecticides could make them an integral part of the biological,
geological and chemical cycles of the earth. Measurable quantities of DDT residues may be
found in air, soil and water several thousand kilometres away from the point where it originally
entered the ecosystem.
MINING SOURCES
Natural or man-made geochemical alterations are also sources of wastewater pollution. Fines
from ore washings disposed off in water suspension may be transferred to the natural water
bodies to pollute them in due course. Mining operation also produces soluble toxic materials
depending on the geological formation. Acid drainage from coal mines and arsenic residue from
gold mines are some of the burning problems of environmental concern.
TYPES OF WATER POLLUTION
There are many types of water pollution because water comes from many sources. Here are a
few types of water pollution:
1. Nutrients Pollution
Some wastewater, fertilizers and sewage contain high levels of nutrients. If they end up in water
bodies, they encourage algae and weed growth in the water. This will make the water
undrinkable, and even clog filters. Too much algae will also use up all the oxygen in the water,
and other water organisms in the water will die out of oxygen from starvation.
2. Surface water pollution
Surface water includes natural water found on the earth's surface, like rivers, lakes, lagoons and
oceans. Hazardous substances coming into contact with this surface water, dissolving or mixing
physically with the water can be called surface water pollution.
3. Oxygen Depleting
Water bodies have micro-organisms. These include aerobic and anaerobic organisms. When to
much biodegradable matter (things that easily decay) end up in water, it encourages more
microorganism growth, and they use up more oxygen in the water. If oxygen is depleted, aerobic
organisms die, and anaerobic organism grow more to produce harmful toxins such as ammonia
and sulfides stop water pollution.
4. Ground water pollution
When humans apply pesticides and chemicals to soils, they are washed deep into the ground by
rain water. This gets to underground water, causing pollution underground.
This means when we dig wells and bore holes to get water from underground, it needs to be
checked for ground water pollution.
5. Microbiological
In many communities in the world, people drink untreated water (straight from a river or stream).
Sometimes there is natural pollution caused by microorganisms like viruses, bacteria and
protozoa. This natural pollution can cause fishes and other water life to die. They can also cause
serious illness to humans who drink from such waters.
6. Suspended Matter
Some pollutants (substances, particles and chemicals) do not easily dissolve in water. This kind
of material is called particulate matter. Some suspended pollutants later settle under the water
body. This can harm and even kill aquatic life that live at the floor of water bodies.
7. Chemical Water Pollution
Many industries and farmers work with chemicals that end up in water. These include chemicals
that are used to control weeds, insects and pests. Metals and solvents from industries can pollute
water bodies. These are poisonous to many forms of aquatic life and may slow their
development, make them infertile and kill them.
8. Oil Spillage
Oil spills usually have only a localized affect on wildlife but can spread for miles. The oil can
cause the death of many fish and stick to the feathers of seabirds causing them to lose the ability
to fly marine oil pollution Do you remember the BP Oil spill in 2010? (Read about it here) Over
1,000 animals (birds, turtles, mammals) were reported dead, including many already on the
endangered species list. Of the animals affected by the spill that are still alive only about 6%
have been reported cleaned, but many biologists and other scientists predict they will die too
from the stress caused by the pollution.
EFFECTS OF WATER POLLUTION
You will notice in the previous pages that water pollution is very harmful to humans, animals
and water life. The effects can be catastrophic, depending on the kind of chemicals,
concentrations of the pollutants and where there are polluted. Below, we shall see a summary of
the effects of water pollution.
The effects of water pollution are varied and depend on what chemicals are dumped and in what
locations.
Many water bodies near urban areas (cities and towns) are highly polluted. This is the result of
both garbage dumped by individuals and dangerous chemicals legally or illegally dumped by
manufacturing industries, health centers, schools and market places.
FACTS ON WATER POLLUTIONDEATH OF AQUATIC (WATER) ANIMALS
The main problem caused by water pollution is that it kills life that depends on these water
bodies. Dead fish, crabs, birds and sea gulls, dolphins, and many other animals often wind up on
beaches, killed by pollutants in their habitat (living environment).
FACTS ON WATER POLLUTIONDISRUPTION OF FOOD-CHAINS
Pollution disrupts the natural food chain as well. Pollutants such as lead and cadmium are eaten
by tiny animals. Later, these animals are consumed by fish and shellfish, and the food chain
continues to be disrupted at all higher levels.
POLLUTION DISEASES
Eventually, humans are affected by this process as well. People can get diseases such as hepatitis
by eating seafood that has been poisoned. In many poor nations, there is always outbreak of
cholera and diseases as a result of poor drinking water treatment from contaminated waters.
DESTRUCTION OF ECOSYSTEMS
Ecosystems (the interaction of living things in a place, depending on each other for life) can be
severely changed or destroyed by water pollution. Many areas are now being affected by careless
human pollution, and this pollution is coming back to hurt humans in many ways.
WATER POLLUTION IN INDUSTRY
IN the United States industry is the greatest source of pollution, accounting for more than half
the volume of all water pollution and for the most deadly pollutants. Some 370,000
manufacturing facilities use huge quantities of freshwater to carry away wastes of many kinds.
The waste-bearing water, or effluent, is discharged into streams, lakes, or oceans, which in turn
disperse the polluting substances. In its National Water Quality Inventory, reported to Congress
in 1996, the U.S. Environmental Protection Agency concluded that approximately 40% of the
nation's surveyed lakes, rivers, and estuaries were too polluted for such basic uses as drinking
supply, fishing, and swimming. The pollutants include grit, asbestos, phosphates and nitrates,
mercury, lead, caustic soda and other sodium compounds, sulfur and sulfuric acid, oils, and
petrochemicals.
In addition, numerous manufacturing plants pour off undiluted corrosives, poisons, and other
noxious byproducts. The construction industry discharges slurries of gypsum, cement, abrasives,
metals, and poisonous solvents. Another pervasive group of contaminants entering food chains is
the polychlorinated biphenyl (PCB) compounds, components of lubricants, plastic wrappers, and
adhesives. In yet another instance of pollution, hot water discharged by factories and power
plants causes so-called thermal pollution by increasing water temperatures. Such increases
change the level of oxygen dissolved in a body of water, thereby disrupting the water's ecological
balance, killing off some plant and animal species while encouraging the overgrowth of others.
WATER POLLUTION IN FOOD INDUSTRY
A food processing industry is involved with the total environment from the farm to the customer.
It is dependent upon good quality water and therefore is aware of water as a commodity which
must be used as efficiently and effectively as possible. Water is absolutely necessary for many
steps in the food processing industry. At present, there is no economical substitute. Conse-
quently, water conservation and water reuse are necessary and most of the industry practices this
in order to conserve this vital natural resource and reduce operating costs. By practising
conservation and reuse, the amount of liquid waste is reduced as is also the pollution potential
from food pro- cessing operations.
MEASURES AGAINST WATER POLLUTION IN FOOD INDUSTRY
Historically, little consideration was given to the reuse of water both because of its abundance
and also because reuse was considered to be hazardous because of the problems of bacterial
contamination with subse- quent spoilage of cans. An example of water use to maintain sanitary
con- ditions is shown in Figure 1 where the relationship of water exchange to bacteriological
conditions shows that unless 40 per cent of the water is exchanged each hour, the growth rate of
bacteriological organisms is extremely high. Of course, in order to overcome this, other means of
control must be used such as chlorination. By development of new techniques such as
chlorination, reuse of water could be considered, but even so, quality is the most essential factor
and therefore sanitary conditions of operation are the controlling criteria for the reuse of water.
Much study and research are required to ascertain the limitations of chlorine as a benefit in order
to prevent bacterial problems in the final product. The National Canners Association has set up
four principal conditions governing the use of re- claimed waters in contact with food products.
They are as follows:
(1) that the water be free of microorganisms of public health significance,
(2) that the water contain no chemicals in concentrations toxic or otherwise harmful to man,
(3) that the water be free of any materials or compounds which could impart discolouration, off-
flavour, or odours to the product or otherwise adversely affect its quality, and
(4) that the appearance and content of the water be acceptable from an aesthetic viewpoint.
WASTE TREATMENT
The National Canners Association developed Table 1 to show the different types of waste and
how they can be treated. The asterisk indicates which of these methods have been studied under
special research projects by the NCA. There is no simple rule of thumb to guide the food
processor into the most practical and economical method of treatment. Each type of system and
approach may have merit, depending upon the peculiarity of the local conditions or
circumstances. The food processor, if he does not have his own sanitary engineering staff, has to
depend upon consulting engineers and should be sure that those whom he calls upon to perform
such services have wide-spread knowledge in the area of the characteristics of food processing
wastes and how they can be treated in order that he can receive through this service the most
economical system possible.
APPLE FACTORY IN CHINA PUNISHED BY WATER POLLUTION
RiTeng, an Apple supplier which makes iPad cases, was charged with pouring untreated metal-
cutting liquid and greasy, waste water into Shanghai's rain water drainage system which runs into
the city's largest river, according to the local environment authority.
The Songjiang Environmental Protection Bureau fined the company, suspended production, and
ordered it to stop the waste outlet from flowing into the drainage system.
Nearby residents said the river had been polluted long before the authority stepped in, but they
had no choice but to continue using the polluted river water to irrigate crops.
"The water had a milky color and looked as if people used it to wash rice," said a local farmer.
"It was very stinky, but we didn't know where the waste came from."
"The grass on the river banks is all dead," said another farmer.
The company insisted that the pollution was unintentional and claimed some workers
"accidentally" discharged water that was used to wash the factory compound into the city's
drainage system.
"We are not the only company around here, and what companies do not discharge waste water?"
an unidentified source in RiTeng's management told local newspaper, National Business Daily.
"It is unfair to blame us for this incident. All of our production waste is treated before being
discharged. This is not a production-related incident."
The source claimed that the company was equipped with imported waste water-treating facilities.
He denied all requests for further information.
SUMMARY:- Apple supplier in Shanghai, which makes iPad cases, has been fined and its
production suspended for allegedly pouring waste chemicals into a local river. The company
denies any wrongdoing. By Liu Jiayi for View from China | February 28, 2013 -- 03:08 GMT