an article on water pollution plzz.....
- Over population, industrialisation and technological advancement has caused pollution of the environment.
- Chemical waste from factories is thrown into water bodies.
- Oil spills also cause water pollution.
- Fish and other aquatic animals suffer as oxygen in the water reduces due to pollution.
- Polluted water becomes unsafe for human consumption.
- Water pollutants can cause skin diseases.
- The government and public has to take proactive steps to check water pollution.
- PM Modi has started the 'Clean Ganga' campaign.
Water covers two-thirds of the Earth’s surface, with over 97% present in the oceans and less than 1% in freshwater streams and lakes. Water is also present in the atmosphere in solid form in the polar icecaps and as groundwater in aquifers (water-bearing rocks) deep underground.
Water has many remarkable properties. It is sometimes referred to as ‘the universal solvent’, readily dissolving a wide range of chemical substances. It also acts as a fluid medium facilitating the dispersal of un-dissolved particulate matter.
Water pollution may be defined as any chemical or physical change in water detrimental to living organisms. It can occur through natural processes, for example by sediments produced by natural erosion. Water bodies are a major recipient of an extensive array of wastes produced by human activity. These may be discharged directly into watercourses by sewers or pipes from factories or be washed down from agricultural or urban areas particularly after heavy rains. Under rather exceptional circumstances, water bodies may become significantly contaminated by the atmospheric deposition of pollutants.Sources and consequences:
Water pollution is a global problem and one that does not respect national boundaries. Sources of pollution may be domestic, agricultural or industrial. In less-developed countries, human and animal waste and sediments from unsound agricultural and forestry practices are the main pollutants. In more-developed countries; industrial pollutants, such as toxic metals, organic Chemicals and heat add to the water pollution problem. The effectiveness of treating wastes prior to their release into the environment determines the balance between potential and actual pollution.Organic oxygen-demanding wastes:
The release of large quantities of oxygen-demanding organic waste into watercourses often has disastrous effects on the indigenous flora and fauna. The primary source of organic waste released into fresh waters is sewage effluent. Other sources include run-off from urban areas and farms, and some industrial effluents. The recent intensification of livestock production, with larger herds concentrated in smaller areas, has exacerbated the problem of organic pollution from farm animal wastes.Plant nutrients:
Aquatic primary productivity is often limited by the availability of inorganic plant nutrients. In freshwater lakes and rivers, the limiting nutrient element is usually phosphorus, whilst in marine waters nitrogen is often in short supply. If small amounts of nutrients enter aquatic ecosystems where they are normally limiting, primary productivity is stimulated. The water body becomes over-enriched by excessive nutrient input and consequently polluted.Acidification:
Both acid rain and acid mine drainage contribute significantly to the acidification of natural waters. These two phenomena are dealt with in detail in this section. However, there are other causes of this particular type of water pollution. For example, the planting of extensive tracts of coniferous forests, usually in upland areas, results in the acidification of the soil and the waters which drain these plantations.Organochlorines:
Organochlorines are, as name suggests, organic compounds containing chlorine. Manufactured organochlorines include a number of pesticides, for example DDT, and polychlorinated biphenyls, or PCBs as they are known. These two groups will be considered separately, although they do share a number of important characteristics. For example, both groups are reported to have endocrine-disrupting properties.
Drilling for oils is one of the major extractive industries. Crude oil is a complex mixture of thousands of different organic molecules, mainly hydrocarbons (aromatics, alkenes and cyclohexanes). It is refined by the process of fractional distillation to yield a number of commercially important products such as petrol, diesel oil and tar. From these different types of oil, seas and rivers are being polluted regularly. Sometime accidental spillage from oil tankers causes drastic damage to the environment through oil pollution. All types of aquatic forms of life thus face the ill-effects.