WATER POLLUTION

                                        

                                    Water Pollution

Definitions

p  Impaired Waters

               Section 303(d) of the Clean Water Act requires states to develop lists of impaired                       waters, those that do not meet water quality standards that states have set for them.

  p  Total Maximum Daily Load

               The law requires that states establish priority rankings for impaired waters and        develop total maximum daily loads (TMDLs) for them. A TMDL specifies the maximum amount of a pollutant that a body of water can receive and still meet water quality standards.            

WATER

              Water is a ubiquitous chemical substance that is composed of hydrogen and

              oxygen and is vital for all known forms of life.

•         In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation.Oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes and ponds 0.6%.

•         Water on Earth moves continually through a cycle of evaporation or transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Over land, evaporation and transpiration contribute to the precipitation over land.

•         Clean, fresh drinking water is essential to human and other lifeforms. Access to safe drinking water has improved steadily and substantially over the last decades in almost every part of the world. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. A recent report (November 2009) suggests that by 2030, in some developing regions of the world, water demand will exceed supply by 50%.

CHEMICALS OF PHYSICAL PROPERTIES OF WATER

ü   Water is the chemical substance with chemical formula H2O: one molecule of                             water has two hydrogen atoms covalently bonded to a single oxygen atom.

ü  Water appears in nature in all three common states of matter and may take many different forms on Earth: water vapor and clouds in the sky; seawater and icebergs in the polar oceans; glaciers and rivers in the mountains; and the liquid in aquifers in the ground.

ü    The major chemical and physical properties of water are:

ü    Water is a tasteless, odorless liquid at standard temperature and pressure. The color of water and ice is, intrinsically, a very light blue hue, although water appears colorless in small quantities. Ice also appears colorless, and water vapor is essentially invisible as a gas.

ü    Water is transparent, and thus aquatic plants can live within the water because sunlight can reach them. Only strong UV light is slightly absorbed.

Taste and Odor

Water can dissolve many different substances, giving it varying tastes and odors. Humans and other animals have developed senses which (more or less) enable them to evaluate the potability of water by avoiding water that is too salty or putrid. Humans also tend to prefer cold water to lukewarm water since cold water is likely to contain fewer microbes. The taste advertised in spring water or mineral water derives from the minerals dissolved in it: Pure H2O is tasteless and odorless. The advertised purity of spring and mineral water refers to absence of toxins, pollutants and microbes.

Water on Earth

•         Main articles: Hydrology and Water distribution on Earth                              

•         A graphical distribution of the locations of water on Earth.

•         Water covers 71% of the Earth's surface; the oceans contain 97.2% of the Earth's water.

•         The Antarctic ice sheet, which contains 90% of all fresh water on Earth, is visible at the bottom. Condensed atmospheric water can be seen as clouds, contributing to the Earth's albedo.

•         Hydrology is the study of the movement, distribution, and quality of water throughout the Earth. The study of the distribution of water is hydrography. The study of the distribution and movement of groundwater is hydrogeology, of glaciers is glaciology, of inland waters is limnology and distribution of oceans is oceanography. Ecological processes with hydrology are in focus of ecohydrology.

WATER CYCLE

§   The sun, which drives the water cycle, heats water in the oceans. Some of it evaporates as vapor into the air. Ice and snow can sublimate directly into water vapor.

§   Rising air currents take the vapor up into the atmosphere, along with water from evapotranspiration, which is water transpired from plants and evaporated from the soil. The vapor rises into the air where cooler temperatures cause it to condense into clouds.

§   Air currents move clouds around the globe, cloud particles collide, grow, and fall out of the sky as precipitation. Some precipitation falls as snow and can accumulate as ice caps and glaciers, which can store frozen water for thousands of years.

§  Snowpacks in warmer climates often thaw and melt when spring arrives, and the melted water flows overland as snowmelt. Most precipitation falls back into the oceans or onto land, where, due to gravity, the precipitation flows over the ground as surface runoff.

§  A portion of runoff enters rivers in valleys in the landscape, with streamflow moving water towards the oceans. Runoff, and ground-water seepage, accumulate and are stored as freshwater in lakes.

WATER POLLUTION

§  Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans, groundwater).

§  Water pollution affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging either to individual species and populations, but also to the natural biological communities.

§  Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds.

SOURCES OF WATER POLLUTION

       

1) INDUSTRY

§  Industry is a huge source of water pollution, it produces pollutants that are extremely harmful to people and the environment.

§  Many industrial facilities use freshwater to carry away waste from the plant and into rivers, lakes and oceans.

§  Pollutants from industrial sources include:

–        Asbestos – This pollutant is a serious health hazard . Asbestos fibres can be inhaled and cause illnesses such as asbestosis, lung cancer, intestinal cancer and liver cancer.

–        Lead – This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Lead is harmful to the health of many animals, including humans, as it can inhibit the action of bodily enzymes.

2) OIL POLLUTION IN WATER

§          Oceans are polluted by oil on a daily basis from oil spills, routine shipping, run-offs and dumping.

§  Oil spills make up about 12% of the oil that enters the ocean. The rest come from shipping travel, drains and dumping.

§  An oil spill from a tanker is a severe problem because there is such a huge quantity of oil being spilt into one place.

§  Oil spills cause a very localised problem but can be catastrophic to local marine wildlife such as fish, birds and sea otters.

§  Oil cannot dissolve in water and forms a thick sludge in the water. This suffocates fish, gets caught in the feathers of marine birds stopping them from flying and blocks light from photosynthetic aquatic plants.

3) RADIO ACTIVE WASTE

§         Nuclear waste is produced from industrial, medical and scientific processes that use radioactive material. Nuclear waste can have detrimental effects on marine habitats. Nuclear waste comes from a number of sources:

§  Operations conducted by nuclear power stations produce radioactive waste. Nuclear-fuel reprocessing plants in northern Europe are the biggest sources of man-made nuclear waste in the surrounding ocean. Radioactive traces from these plants have been found as far away as Greenland.

§  Mining and refining of uranium and thorium are also causes of marine nuclear waste.

HARMS OF WATER POLLUTION

§  Virtually all types of water pollution are harmful to the health of humans and animals. Water pollution may not damage our health immediately but can be harmful after long term exposure. Different forms of pollutants affect the health of animals in different ways:

§  Heavy metals from industrial processes can accumulate in nearby lakes and rivers. These are toxic to marine life such as fish and shellfish, and subsequently to the humans who eat them. 

§  Industrial waste often contains many toxic compounds that damage the health of aquatic animals and those who eat them. Some of the toxins in industrial waste may only have a mild effect whereas other can be fatal. They can cause immune suppression,  acute poisoning.

§  Microbial pollutants from sewage often result in infectious diseases that infect aquatic life and terrestrial life through drinking water. Microbial water pollution is a major problem in the developing world, with diseases such as cholera and typhoid fever being the primary cause of infant mortality.

§  Organic matter and nutrients causes an increase in aerobic algae and depletes oxygen from the water column. This causes the suffocation of fish and other aquatic organisms.

§  Sulfate particles from acid rain can cause harm the health of marine life in the rivers and lakes it contaminates, and can result in mortality.

§  Suspended particles in freshwater reduces the quality of drinking water for humans and the aquatic environment for marine life. Suspended particles can often reduce the amount of sunlight penetrating the water, disrupting the growth of photosynthetic plants and micro-organisms.

PREVENTIONS

• If you want to help keep our waters clean, there are many things you can do to help. You can prevent water pollution of nearby rivers and lakes as well as groundwater and drinking water by following some simple guidelines in your everyday life.
• Conserve water by turning off the tap when running water is not necessary. This helps prevent water shortages and reduces the amount f contaminated water that needs treatment.
• Be careful about what you throw down your sink or toilet. Don't throw paints, oils or other forms of litter down the drain.

§  Use environmentally household products, such as washing powder, household cleaning agents and toiletries.

§  Take great care not to overuse pesticides and fertilisers. This will prevent runoffs of the material into nearby water sources.

§  By having more plants in your garden you are preventing fertiliser, pesticides and contaminated water from running off into nearby water sources.

§  Don't throw litter into rivers, lakes or oceans. Help clean up any litter you see on beaches or in rivers and lakes, make sure it is safe to collect the litter and put it in a nearby dustbin.

MAKING OURSELVES SAFE

• Water fit for human consumption is called drinking water or potable water. Water that is not potable can be made potable by filtration or distillation (heating it until it becomes water vapor, and then capturing the vapor without any of the impurities it leaves behind), or by other methods (chemical or heat treatment that kills bacteria). Sometimes the term safe water is applied to potable water of a lower quality threshold . Water that is not fit for drinking but is not harmful for humans when used for swimming or bathing is called by various names other than potable or drinking water, and is sometimes called safe water, or "safe for bathing". Chlorine is a skin and mucous membrane irritant that is used to make water safe for bathing or drinking. Its use is highly technical and is usually monitored by government regulations (typically 1 part per million (ppm) for drinking water, and 1–2 ppm of chlorine not yet reacted with impurities for bathing water).

SCARCE OF DRINKING WATER

•          This natural resource is becoming scarcer in certain places, and its availability is a major social and economic concern. Currently, about a billion people around the world routinely drink unhealthy water.

•           Most countries accepted the goal of halving by 2015 the number of people worldwide who do not have access to safe water and sanitation during the 2003 G8 Evian summit. Even if this difficult goal is met, it will still leave more than an estimated half a billion people without access to safe drinking water and over a billion without access to adequate sanitation.

•           Poor water quality and bad sanitation are deadly; some five million deaths a year are caused by polluted drinking water. The World Health Organization estimates that safe water could prevent 1.4 million child deaths from diarrhea each year.

•          It is, rather, the distribution of potable and irrigation water which is scarce, rather than the actual amount of it that exists on the earth.

What is Sewage treatment

•          Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants from wastewater  and household sewage, both runoff and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants.

ITS OBJECTIVES

•          Its objective is to produce a waste stream (or treated effluent) and a solid waste or sludge suitable for discharge or reuse back into the environment. This material is often inadvertently contaminated with many toxic organic and inorganic compounds.

HOW DOES IT GET CREATED?

•          Sewage is created by residences, institutions, and commercial and industrial establishments. Raw influent (sewage) includes household waste liquid from toilets, baths, showers, kitchens, sinks, and so forth that is disposed of via sewers.

•           In many areas, sewage also includes liquid waste from industry and commerce. A lot of sewage also includes some surface water from roofs or hard-standing areas.

•           Municipal wastewater therefore includes residential, commercial, and industrial liquid waste discharges, and may include storm water runoff.

•          Examples of treatment processes used for storm water include sedimentation basins, wetlands, buried concrete vaults with various kinds of filters, and vortex separators (to remove coarse solids.

Pre-treatment

•          Pre-treatment removes materials that can be easily collected from the raw wastewater before they damage or clog the pumps and skimmers of primary treatment clarifiers.

PRIMARY TREATMENT

•          In the primary sedimentation stage, sewage flows through large tanks, commonly called "primary clarifiers" or "primary sedimentation tanks".

•           The tanks are large enough that sludge can settle and floating material such as grease and oils can rise to the surface and be skimmed off.

•          The main purpose of the primary sedimentation stage is to produce both a generally homogeneous liquid capable of being treated biologically and a sludge that can be separately treated or processed.

SECONDARY TREATMENT

•          Secondary treatment is designed to substantially degrade the biological content of the sewage which are derived from human waste, food waste, soaps and detergent.

•          The majority of municipal plants treat the settled sewage liquor using aerobic biological processes. For this to be effective, the biota require both oxygen and a substrate on which to live.

•          There are a number of ways in which this is done. In all these methods, the bacteria and protozoa consume biodegradable soluble organic contaminants (e.g. sugars, fats, organic short-chain carbon molecules, etc.) and bind much of the less soluble fractions into floc.

The processes of secondary treatment.

•          There are many methods through which the wastewater undergoes in the secondary treatment in order to get purified.the process include:-

•           Activated sludge

•           Surface-aerated basins

•           Filter beds (oxidizing beds)

•           Biological aerated filters

•           Membrane bioreactors

•           Secondary sedimentation

•          Rotating biological contactors

USES OF WATER

                 There are lots of uses of water. They are listed below :

          1. Water is used for drinking, washing , bathing , etc.

          2.Its also used for irrigation purpose.

          3. A lot of water is used to make food. Almost every food contains water.

          4. Water is also used in industry

          5. Water is used in dams to manufacture hydro-electricity

                 6. Its also used in vehicles to make the temperature of the engine to cool down.

          7. Its also used in construction work.

Do’s and Dont’s of water pollution

§  Do’s

v  Reuse of water whenever possible, Kitchen water can be used for watering the plant.  

v  Plan your kitchen activity to avoid wastage of fuel and water.                  

v  Plastic materials can be a murder weapons for wildlife, minimise their use. Blown from land and roadsides, they often end up in the water, where they can entangle and kill birds and fishes.

v  Take showers instead of baths. Showers use less water - if you limit them to five minutes. Install low-flow shower-heads

v  Use sprinkler for irrigation.

v  Use scientific method of application fertilizers. .               

v  Run your dishwasher, washing machine, and dryer only when you have full loads. · When possible, use an outdoor clothesline instead of a clothes dryer.

v  Fix leaks promptly. A dripping joint can waste more than 76 liters of water a day.

§ 

        DONT'S

Ø  Don't keep on the tap running while having, bath, brushing teeth, or washing dishes it wastes about 2 liters of water every minute.

Ø  Don’t hose down your lawn or corridor to clean it. Sweep it off.

Ø   Don’t wash the clothes and kitchen utensils in the water bodies

Ø  Don’t litter. When camping, keep the areas clean.

Ø  Avoid throwing flowers, sweets, puja materials into a river. It will degrade the quality of water. The river wont be happy with this.

Ø  Avoid throwing dead bodies in a river. This will ultimately landing in the mouth of dogs, vultures & other animals.

Ø  Never dump anything into the water bodies.

Ø  Avoid use of weedicides.