The main source of water pollution are as follows:
1. Domestic Waste : Discharge of untreated domestic waste, sewage into rivers and lakes contains the chemicals present in soaps, detergents and other cleaning agents, decayed food particles. Sewage carries many kinds of disease causing germs . It also contains many kinds of worms such as tape worms, hook worms etc.
2. Industrial Waste : The discharge of toxic industrial wastes contains toxic chemicals such as cyanide, cadmium mercury lead, arsenic chromium which are highly poisonous. They make river water unfit for the use of man and aquatic plants and animals.
3. The waste water from hospitals could contain harmful chemicals and different types of disease-causing microorganisms.
4. Agricultural Waste : Fertilisers, pesticides and other chemicals are used for increasing agricultural productivity all over the world. These are washed away by rainwater into water sources like river. Pesticides can poison fish as well as the animals (including human) that eat them.
To produce more food for growing human population some fungicides and insecticides are used to kill fungi and insects, etc., for example DDT. But the increasing use is dangerous because it is non-biodegradable. Along with rain water it goes into the water.
5. Deforestation : We are polluting water also by cutting trees and by removing vegetation. The rain water goes to small drains then to big drains, to streams and ultimately to rivers. When top soil is covered with trees and other vegetation much of the rain water is retained by the soil and the extra water which flows into the water bodies does not contain much dirt and filth in it. But, when top soil is not covered with vegetation the rain washes away the top fertile soil which pollutes the various water bodies.
6. Thermal Pollution : Some factories and power generators are located near the lakes and rivers. Larger quantities of heated water is discharged in ponds, lakes and rivers. The hot water is also a kind of pollution. Many aquatic organisms cannot tolerate the rapid change in the temperature and therefore they may die. Only the organisms which can survive in warm temperature may live.
Which of the following options will not help in prevention of water pollution? | |||
Right Option : D | |||
View Explanation |
Which of the following statements is incorrect? | |||
Right Option : D | |||
View Explanation |
To produce more food for growing human population some fungicides and insecticides are used to kill _____________________. | |||
Right Option : A | |||
View Explanation |
Being a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
It was good as the experience because as we had come here we had been improved in a such envirnment created here.Extra is taught which is beneficial for future.
Abhyas is a complete education Institute. Here extreme care is taken by teacher with the help of regular exam. Extra classes also conducted by the institute, if the student is weak.
About Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
My experience with Abhyas academy is very good. I did not think that my every subject coming here will be so strong. The main thing is that the online tests had made me learn here more things.
It was a good experience with Abhyas Academy. I even faced problems in starting but slowly and steadily overcomed. Especially reasoning classes helped me a lot.
A marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
My experience with Abhyas is very good. I have learnt many things here like vedic maths and reasoning also. Teachers here first take our doubts and then there are assignments to verify our weak points.
It has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
I have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying