Water pollution,water pollution causes,types of water pollution, prevention of water pollution

  Water pollution

Water pollution can be defined as the presence in water, of some foreign substances or impurities in such quantity so as to constitute a health hazard by lowering the water quality and making it unfit for use .

Types of water pollution

(1)- Natural water pollution

When the dust particles found in the air dissolve with the rain at the time of rain, then the rainwater becomes acidic.  SO2 dissolves with rainwater to form sulfuric acid.  Due to which the pH value of the water is less than 5.7, the rainwater becomes acidic.  And this is called acid rain.  In addition, carbon monoxide and carbon dioxide also dissolve in water to form carbonic acid. This also makes water acidic.  And causes acid rain.

 Acid rain has a very destructive effect on animals, trees, plants, natural balance and substances. 

Agricultural pollution 

Many types of chemical extracts and pesticides are used for agriculture such as phosphate, nitrate and urea etc. and D.D.T, BHC etc. in pesticides.  These substances also dissolve in the water along with the rain water, and flow into the water sources, which causes water pollution. 

Mining pollution  

Minerals are mined to obtain, which brings out other impurities along with the soil which together with water makes the water toxic. It has to be washed to get additional pure minerals. Due to which the dirt extracted pollutes the water. 

Municipal pollution 

The waste discharged from the houses goes through rivers and lakes through rivers and lakes. Similarly, the toxic material extracted from factories is also found in the rivers. Sewage contains organic matter, non-organic matter and other toxic substances. When the decomposition of organic matter takes place, it costs oxygen. This oxygen is supplied by dissolved oxygen in the river water. Becomes deficient. And the self-effacing capacity of the river is gone. 

Effect of water pollution 

1) - Effect on humans

 Human beings have to face many types of health related problems with polluted water. Polluted water causes diseases like jaundice, cholera, diarrhea, typhoid, indigestion.

 (2) - Effect on aquatic ecosystem

 There are aquatic ecosystems of ponds, rivers, lakes, canals and reservoirs, etc. There are many species of flora, flora which gets destroyed due to contaminated water and due to lack of food chain for the remaining animals, they also get destroyed.  is.

 (3) - Effect on tree plants

 If polluted water is used for irrigation, the toxins reach the tree plants with food, due to which their growth is stopped and their fruits become poisonous.  When a man consumes these fruits, he also becomes ill.

 Waste water treatment 

Wastewater,whether domestic or industrial have several undesirable components.the organic and inorganic pollutants that are potentially harmful to the environment and human health. The treatment of waste water and its proper management has become a necessity in order to conserve this vital resource. The main aim of waste water treatment is the removal of contaminants from waste water treatment in carried out in three stages 

Primary treatment

Secondary treatment

Tertiary treatment 

 Primary treatment 

Waste water contains a wide variety of soluds of various shapes ,sizes and densities.The primary treatment is of general nature and is used for removing suspended solids, odour, colour and to neutralize the high or low pH in the case of industrial effluents.this stages exploits the physical and chemical properties of the contaminants and removes the suspended and floating matter by screening , sedimentation, floatation, filtration, precipitation etc.

primary treatment

In this treatment, paper cloth, soil, gravel, sand, grease, grease, wood etc. are separated. It has the following parts.

 

(a)-Screenings

 There are round or square holes of the same size in six layers, due to which large sizes of clothes, gravel, paper, wood etc. are not able to pass. Which are removed from time to time.

 (b) grit chamber

Inorganic materials of size less than 6 mm are separated from the grit chamber, such as gravel, sand, ballast, etc. In this, the velocity of sewage is reduced so that the grit easily settles in the bottom. Then it is separated. Two cells are made for this. When one chamber is in use, the other is cleaned.

 (c) skimming tank

A skimming tank is used to remove oily materials such as soap, lubricants, grease etc. The tank is made of backlash walls to separate them. And the bottom of the tank is equipped with air diffusers. At high speed, the air is sent upwards. This causes the lubricating material to turn into foam, which is separated into the foam pool, thus the sewage enters from the inlet and the lubrication is removed in the foam tank. 

Secondary treatment

 (a) Sedimentation

 The sedimentation process perform in a sedimentation tank. In which the velocity of sewage is reduced very much, due to which the heavy particles present in it start to sit down due to their weight, in this process 80% -90% particles sit down.

Sedimentations are two type

 1) - Plain sedimentation

 2) - Sedimentation with coagulant

 1) - Plain sedimentation

Plain sedimentation is the process of removing suspended matters from the water by keeping it quiescent in tanks, so that suspended matter may settle down in the bottom due to force of gravity.

(2) - Sedimentation with coagulant 

The coagulation process involves adding iron or aluminum salts, such as aluminum sulphate,
ferric sulphate, ferric chloride or polymers, to the water. These chemicals are called coagulants, and have a positive charge. The positive charge of the coagulant neutralizes the negative charge of dissolved and suspended particles in the water. When this reaction occurs, the particles bind together, or coagulate (this process is sometimes also called flocculation). The larger particles, or floc, are heavy and quickly settle to the bottom of the water supply. This settling process is called sedimentation. The following diagram illustrates the basic reactions and processes that occur during coagulation. 

Filteration

Water flows through a filter designed to remove particles from within it. The filters are made of layers of sand and gravel, and in some cases, crushed anthracite. Filtration collects the suspended impurities in water, enhancing the effectiveness of disinfection.

Disinfectant

Water disinfection means the removal, deactivation or killing of pathogenic microorganisms. Microorganisms are destroyed or deactivated, resulting in termination of growth and reproduction. When microorganisms are not removed from drinking water, drinking water usage will cause people to fall ill.

Sterilization is a process related to disinfection. However, during the sterilization process all present microorganisms are killed, both harmful and harmless microorganisms.

 After this action, sewage is dumped into a river or lake.

 Water pollution control measures

1) The waste water is treated and must be matched in the rivers.

 (2) - Solid waste should be prevented from disposal at open places.

 (3) Bio-pesticides should be used instead of chemical pesticides.

 (4) Rainwater should not be allowed with sewage.

 (5) In place of fertilizers, nitrogen-fixing plants should be used.

Also see...https://generalawareness2222.blogspot.com/2021/02/environmental-studies.html

https://generalawareness2222.blogspot.com/2021/02/foundation-engineering.html.

https://generalawareness2222.blogspot.com/2021/02/deep-foundation.