Water Pollution

Water Pollution

The agent that causes the pollution is called pollutants. Any condition to environment components that threatens the health survival and activities of humans or other living organisms is called pollution.

Water pollution is a major global problem. 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. 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 bay and estuarine square miles were classified as polluted.

What is Water Pollution?

Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans and groundwater). Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds.

Water Pollution

Or the presence of extraneous materials in the water in sufficient quantities and durations to cause harm us, other forms of life and materials change in water quality and ecosystem is called water pollution.

Water pollution affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities.

Any chemicals, physical, biological change in water quality that has a harmful effect on living organisms and makes water unsuitable for desired uses is called polluted water.

Sources of water pollution:

Point sources 
Non-point sources

1) Point sources

Pollutants discharge from one sources. A point source of pollution is a single identifiable localized source of water pollution. It involves discharge from factories, sewage system, power plants, underground coal mines, and oil wells. These sources are easy to identify and therefore easy to monitor and regulate than nonpoint sources. A point source has negligible extent, distinguishing it from other pollution source geometries Water pollution from an oil refinery wastewater discharge outlets. In developing countries such discharges are largely uncontrolled.

2) Non-point sources

Non–point source pollution refers to diffuse contamination that does not originate from a single discrete source. Non-point sources are those sources that can’t be traced to any single site of discharge. They occurs usually large lands. Some of the most prominent nonpoint sources of water pollution are agricultural runoff from cropland and animal farm, storm water from drainage from street and parking lot and from atmospheric deposition little process have been made in controlling non-point sources of water pollution because of the difficulty and expense of identifying and controlling discharge from so many diffused sources.

Two basic strategies are employed in attempting to bring water pollution under control:

1.       Reduce or remove the sources (best)

2.       Treat water (wastewater treatment)

Some of the water pollutants are discussed below:-

1)     Pathogens: The most serious and widespread water pollutants are the infectious agents that cause sickness and death. Pathogens are the diseases causing bacteria, viruses and other parasite organisms that grow and multiply within the host. The excrement from humans and other animals infected with certain pathogens contains large number of these organisms and contaminated water is responsible for the spread of many contagious diseases.

Water Pollution

Public health—Sanitation = Good medicine

2)     Organic Wastes: Along with the pathogens human and animal wastes contain organic matter that creates serious problems if it enters bodies of water untreated. Other kind of organic matter like leaves, grass, clippings, trash and so forth. This wastes are biodegradable. The amount of oxygen that water can hold in solution in severely limited when bacteria and detritus feeders decompose organic matter in water, they compose oxygen gas dissolved in the water. In cold water do not reach up to 10 ppm much less can be held in warm water. Oxygen demanding wastes are substances that at oxidise in the receiving body of water. Oxygen demanding wastes threatens the aquatic life.

BOD: Biochemical oxygen demand is a measure of the amount of organic material in water, stated in terms of how much oxygen will be required to break it down biologically, chemically or both

3)     Chemical Pollutants

Water is the excellent universal solvent, have ability to hold many chemicals substances in solution that have undesirable effects. Water soluble inorganic chemicals constitute an important class of pollutants that include heavy metals like lead, mercury, arsenic, nickel and so forth. Acids from mine drainage and salt.

Organic chemicals:

·         Hydrocarbons

·         Petroleum products

·         Detergents and soap

·         Cleaning solvents

·         Pesticides

Water Pollution

                These chemical pollutants are toxic in even small amount which is dangerous for humans, aquatic and ecosystem.

            4) Nutrients:

            They are essential elements required by plants and other living things. Some of the in organic chemicals carried in solutions in all bodies of water called nutrients. Nitrogen, phosphorus, carbon, sulphur, calcium, potassium, iron, manganese, boron and cobalt al are required by living things.  Nutrients can be considered as pollutants when their concentration are sufficient to allow excessive growth of aquatic plants.. Suitably treated and used in moderate quantities, sewage can be a fertilizer: it returns important nutrients to the environment, such as nitrogen and phosphorus, which plants and animals need for growth. 

The trouble is, sewage is often released in much greater quantities than the natural environment can cope with. Chemical fertilizers used by farmers also add nutrients to the soil, which drain into rivers and seas and add to the fertilizing effect of the sewage. Together, sewage and fertilizers can cause a massive increase in the growth of algae or plankton that overwhelms huge areas of oceans, lakes, or rivers. Especially algae because of the nutrient enrichment algal bloom takes place. Algae and decaying organic matter add colour turbidity, odours and objectionable tastes to water that are difficult to remove and that may greatly reduce its acceptability as a domestic water source. The process of nutrient enrichment is called eutrophication. This is known as a harmful algal bloom it can turn the water red. It is harmful because it removes oxygen from the water that kills other forms of life, leading to what is known as a dead zone.

5)     Thermal pollution:

A large stream-electric power plant requires an enormous amount of cooling water. If that heat release in water, resulting temperature can adversely affect life in the vicinity of the thermal plume. When temperatures increases metabolism rate of microorganisms also increases and dissolved oxygen level decreases by 2-3 ppm.

6)     Sediments:

As natural landforms weather, especially during streams, a certain amount of sediments enters streams and rivers. Erosion, deforestation, overgrazing uncontrolled agriculture are main cause of the huge amount of soil loss. Sediments have direct and extreme physical impacts on streams and rivers. (Sand, silt and clay)

7)     Radioactive Waste:

People view radioactive waste with great alarm—and for good reason. At high enough concentrations it can kill; in lower concentrations it can cause cancers and other illnesses. The biggest sources of radioactive pollution in Europe are two factories that reprocess waste fuel from nuclear power plants.

Water Pollution

Water quality criteria and standard:

When water is considered polluted?

The Quality of water is of vital concern for mankind since it is directly linked with human welfare. Not only should human being the water quality be maintained for all living beings and planet earth to maintain proper cycling of planet.

EPA of US listed 167 chemicals and substances as criteria pollutants. The majority of these toxic chemicals but mainly are also natural chemicals or conditions that describe the state of water such as nutrients, hardness, acidity, etc. Drinking water standard are sticker than other water quality standard. It cover some 94 chemical substances as contaminants.

Parameters	USPH Standard
Colour, odour, taste	Less
PH	6-8
Dissolved oxygen	4-6 ppm
Chemical oxygen demand	4 ppm
Total bacteria count	100000
Suspended solid	5
Chloride, sulphate	250 ppm
Cyanide	0.05 ppm
Nitrate+ nitrile	<10
Arsenic	0.05
Calcium	100
Magnesium	30
Barium	1
Cadmium	0.01
Copper	1
Iron	<0.3
Lead	<0.05
Mercury	0.001
Silver	0.05
Zinc	5.5
manganese	<0.05

 For More Articles Click Here

 Please like my facebook Page Here