Freshwater pollution especially, driking water contaminates and their analysis and control measures, use conventional and advanced treatments....

1. WATER POLLUTION
BALAMURUGAN RAMAN
POSTGRADUATE STUDENT
PG AND RESEARCH DEPARTMENT OF ZOOLOGY
A.P.A COLLEGE OF ARTS AND CULTURE, PALANI

2. INTRODUCTION
 žWater is mainly vital liquid for maintaining the life on the earth. It is a natural supply for drinking,
domestic, industrial and irrigation purposes.
 žAs of nowadays only earth is the planet having about 70% of water. About 97% water is exists in marine
that is not suitable for drinking and only 3% is fresh water where in 2.97% is comprised by glaciers and
ice caps and remaining slight portion of 0.3% is available as a surface and ground water for human use. ž
 Fresh water is already a limiting resource in numerous parts of the world. In the next century, it will
become even more limiting due to amplified population, urbanization and climate change.

3.  žIn developing countries, drinking water supply lines and open sewage drains are laid side by side resulting in
repeated contamination of water.
 žWater is continuously being polluted and harmful for human use due to high growth of population, deforestation,
land degradation, increase in industries, organic matter throwing away of polluted water and chemical effluents
into canals and other water sources.

4. MAJOR SOURCES OF WATER POLLUTION
Microorganisms:
 Escherichia coli is a member of faecal coliforms that polluted the drinking water
from human and animal faecal waste.
 žThe consequences of waterborne bacteria and virus infections are polio, hepatitis,
cholera, typhoid, diarrhea etc.
 Example : Diarrhea is the major cause for the death of more than 2 million people
per year world-wide, mostly children below the age of five. It is the world’s
second leading killer of children below the age of five after pneumonia, claiming
about 1.5 million children a year more than AIDS and measles combined.

5. Heavy metals:
 Pollution of aquatic ecosystems by metals like Mn, Ni, Cr, Cu, Zn etc., It present in a
mixture of industrial effluents.
 žCr absorption by duckweed, and Cr and Mn uptake by Hydrilla and the same by
mosses. Hg uptake hydrophytes and herbivorous fishes.
 Accumulation of Cu, Pb, Mn and Fe by Hydrodictyon . Cd and Pb added by rooted
aquatic plants. žIn current years, heavy metals such as Pb, As, Mg, Ni, Cu, and Zn have
received significant attention due to causing health problems.

6.  žAdditionally, the heart diseases, renal associated problems, nerve and brain
diseases, and cancer are related to the traces of metals such as Cd and Cr as
reported in epidemiological studies.
 The Pb is known to delay the physical and mental development in infants, while
As and Hg can cause serious poisoning with skin pathology and cancer and
additional damage to kidney and liver, in that order .

7. ANALYSIS OF BASIC WATER QUALITY PROPERTIES
 It is very necessary and significant to test the water before it is used for drinking, domestic, agricultural or industrial purpose.
 Temperature : In an established system the water temperature controls the rate of all chemical reactions, and inhibit fish growth,
reproduction and immunity. Severe temperature changes can be lethal to fish.
 pH : Assessment range of pH from 7 to 14 is alkaline, from 0 to 7 is acidic and 7 is neutral. Majority drinking water pH lies from 4.4 to
8.5. The pH level usually ranges from 0 to 14.
 Turbidity : Suspension of particles in water meddlesome with passage of light is called turbidity. Turbidity is caused by wide different of
suspended particles. Turbidity can be calculated either by its effect on the transmission of light which is termed as Turbiditymetry.
 T.D.S : Variance of total solids and suspended solids is used to conclude the filterable solids by the aid of filtrate and following the
procedure as above. In water sample it can also be likely from conductivity measurement.

8.  Electrical conductivity: Conductivity is the capability of water to carry an electrical current and varies both with number and types of
ions the solution contents. In contrast, the conductivity of distilled water is below 1 µmhos/cm.
 Total alkalinity: Alkalinity is the sum total of components in the water that tend to raise the pH to the alkaline side of neutrality. It is
calculated by titration with standardized acid to a pH value of 4.5 and is expressed commonly as milligrams per liter as calcium carbonate
(mg/l as CaCO3). Generally occurring materials in water that increase alkalinity are carbonate, phosphates and hydroxides.
 Nitrate is produced from chemical and fertilizer industries, matters of animals, decline vegetables, domestic and industrial discharge.
Chloride is activities carried out in agricultural part, industrial running and from chloride stones.
 Chemical Oxygen Demand and Biochemical Oxygen Demand: COD is a determine of the oxygen required for the chemical oxidation
of organic matter with the help of strong chemical oxidant. COD determination has an lead over BOD determination in that the result can
be obtained in about 5 hours as compared to 5 days compulsory for BOD test. BOD is a determine of organic material in water, specified
in mg/l.

9. CONTROL MEASURES
Conventional method - Filtration:
 Filtration, which removes particles matter from water by forcing the water to pass through porous media.
 The filtration system consist of filters with varying sizes of pores, and is often made up of sand, gravel and
charcoal. The particles that are removed from the water in filtration depend upon the volume of filters that are
used.
 The sand filtration removes bacteria, protozoa and viruses and produces basically clean water, though it is still
advisable to use a purifier as a precautionary measure.

10. Conventional method - Disinfection:
 It is biological pollutants can be classified into three categories, namely, microorganisms, natural organic matter,
and biological toxins. Microbial contaminants consist of human pathogens and free living microbes. The
elimination of cyanobacterial toxins is an issue in conventional water treatment systems.
 The removal of whole cyanobacterial cells with their cellular compounds through water treatment would
potentially decrease the concentration of taste, odour and toxic cell metabolites present in the treated water. In this
study, the effect of conventional water treatment processes using aluminum sulphate (called alum).

11. Advanced method - Nanotechnology:
 There are many different types of nanomaterials such as silver, titanium, and zinc capable of disinfecting waterborne disease
causing microbes. Due to their charge capacity, they possess antibacterial characters.
 Silver nanoparticle is the majority widely used material due to its low toxicity and microbial inactivation in water with well-
reported antibacterial functions. Silver nanoparticles are derivative from its salts like AgNO3 and AgCl2. And different types of
nanomaterials have been introduced for removal of heavy metals from water.
 TiO2 photocatalysts and metallic and metal-oxide nanoparticles are among the most promising nanomaterials with antimicrobial
characters.
 Contaminate water such as nanosorbents including CNTs, zeolites, and dendrimers and they have special adsorption properties.
Metal based nanoparticles proved to be superior in removing heavy metals than activated carbon.

12. Advanced method - Hydrolytic enzymes:
 Hydrolytic enzymes displace major chemical bonds in the toxic molecules and results in the decline of their
toxicity. This activity is effective for the biodegradation of oil spill, organophosphate, carbonate insecticides.
 The hydrolytic enzymes such as amylases, proteases, lipases, DNases, and xylanases have fairly diverse potential
usages in various parts such as food industry, feed additive, biomedical sciences, and chemical industries.

13. CONCLUSION
From the above study we come to a conclusion that the water pollution reached to the alarming stage. The quality
of water in the world has degraded, through the situation in India is more severe. So, each one of us take part in the
prevention of water bodies from contamination. We should aware of the facts that considerable amount of
xenobiotic compounds has reported in different target organs that leads to death now-a-days. We should think of
our older generations which have still to appear on this world. We should think that we are not the last generation
to flourish on this earth. We leave or provide the pollution free environment, and good water source to our future
generations