X. Water Supply and Water Disposal

Водоснабжение и водоотведение

 

Текст 1

Purification

 

The water industry provides drinking water and wastewater services (including sewage treatment) to households and industry, water purification facility.

In the developing world, 90% of all wastewater still goes untreated into local rivers and streams. The processes generally employed in making water safe for water supply include coagulation, filtration, and disinfection. Water from some sources must be treated also for the removal of color, taste, and odor. Coagulation is commonly effected by adding to the water a salt of aluminum (usually aluminum sulphate) or ferric iron. A precipitate forms and causes a clumping of the bacteria and other foreign particles which then settle out during the several hours of sedimentation. In this way 85% or more of the bacteria and suspended particles can be removed.

Activated carbon is sometimes added before sedimentation to remove tastes and odors. In the process of filtration the water is allowed to pass through layers of fine sand to remove remaining germs and particles. Chlorine is commonly used to destroy harmful bacteria persisting in a municipal water supply after the other treatments. Chlorine dioxide has more recently been found effective as a destroyer of bacteria as well as a means of removing unwanted tastes and odors. Other means of destroying germs include the use of ozone and of ultraviolet light. Some water supplies are aerated, i.e., exposed to the action of air and sunlight either through sprays or by running over coarse gravel; taste and odor are improved and some germs are destroyed.

 

1. What does the water industry provide?

2. What do the processes generally employed in making water safe for water supply include?

3. What must be treated for the removal of color, taste, and odor?

4. Why is activated carbon added before the sedimentation?

5. What has been found effective as a destroyer of bacteria as well as a means of removing unwanted tastes and odors?

6. What are ozone and ultraviolet light used for?

7. When are taste and odor improved and some germs destroyed?

Текст 2

Water Supply

 

Water is a common chemical substance that is essential for the survival of all known forms of life. All known forms of life depend on water. Humans require water that does not contain too many impurities.

The distribution of drinking water is done through municipal water systems or as bottled water. Governments in many countries have programs to distribute water to the needy at no charge. Others argue that the market mechanism and free enterprise are best to manage this rare resource and to finance the boring of wells or the construction of dams and reservoirs. Water supply facilities include for example water wells cisterns for rainwater harvesting, water supply network, water purification facilities, water tanks, water towers, water pipes including old aqueducts. Atmospheric water generator is in development. Drinking water is often collected at springs, extracted from artificial borings in the ground, or wells.

Building more wells in adequate places is thus a possible way to produce more water, assuming the aquifers can supply an adequate flow. Other water sources are rainwater and river or lake water. This surface water, however, must be purified for human consumption. This may involve removal of undissolved substances, dissolved substances and harmful microbes. Popular methods are filtering with sand which only removes undissolved material, while chlorination and boiling kill harmful microbes. Distillation does all three functions. More advanced techniques exist, such as reverse osmosis. Desalination of abundant ocean or seawater is a more expensive solution used in coastal arid climates.

1. What is a common chemical substance that is essential for the survival of all known forms of life?

2. How is the distribution of drinking water done?

3. What do water supply facilities include?

4. Building more wells in adequate places is a possible way to produce more water, isn’t it?

5. What must be purified for human consumption?

6. What does filtering with sand remove?

7. Where is desalination of abundant ocean or seawater used?

 

Текст 3

Sewerage

 

The problem of protecting natural water resources has grown very pressing for many countries since the beginning of the second half of the 20th century. The development of human society, the growth of civilization and social and technical progress have resulted in the changing of the composition of natural water resources. The rivers, lakes and ground-waters contain today the products of mechanical, chemical and biological pollution.

The waste products that result from the daily activities in a community are of two general types: the liquid waste, known as sewage and the solid wastes, known as refuse. The different wastes are the following: the wastes from lavatories, baths, sinks, and laundry tanks in residences, institutions, and business buildings; wastes from various types of manufacturing or industrial plants, and the surface run-off from storms or street-flushing operations.

Sewage may also be divided according to its source into the following three

classes. The sewage from institutions and business buildings is called domestic sewage, sanitary sewage or house sewage; that resulting from manufacturing or industrial processes is known as industrial waste; and that from run-off during storms is called storm sewage. A combination of domestic sewage, industrial waste water is called combined sewage. The removal of all kinds of sewage is usually accomplished by means of sewers. The sewers are placed in the streets below the ground surface. The general process of removing sewage is designated as sewerage and the entire system of sewers including a sewage treatment plant is known as a sewerage system.

In conclusion it should be stressed that with the growth of population many modern treatment systems have been built and much more is still to be done in this field.

1. When has the problem of protecting natural water resources grown?

2. What have resulted in the changing of the composition of natural water resources?

3. The rivers, lakes and ground waters contain today the products of mechanical, chemical and biological pollution, don’t they?

4. What waste products do you know?

5. What is called domestic sewage, sanitary sewage or house sewage?

6. What is known as industrial waste?

7. What is called combined sewage?

 

Oral Topics

Student’s Life

My name is Vladimir Petrov. I was born on the 2-nd of April 1986. I am twenty three years old. I'm from Russia. I am a first-year student of Voronezh State University of Architecture and Civil Engineering. I study at the correspondence department.

Here are some words about my student's life.

The academic year is divided into two terms from September till January and from February till July. Twice a year at the end of each term students have sessions when they take several exams and credit tests.

Students are divided into academic groups. There are 30 students in each as a rule. Every group elects a monitor. The monitor is responsible for the group.

Students attend lectures and practical classes at the university. They study different subjects such as: Mathematics, Physics, Chemistry, Computers' Technology, Economics, Concrete Structures, Theoretical and Structural Mechanics, Strength of Materials, Geodesy, Hydrology, Water Supply and Disposal Systems, Heat and Gas Supply, Building Materials, Automobile Roads and Aerodromes, Economics and Management in Civil Engineering, Humanities and Foreign

Languages. During lectures they take notes. At practical classes and seminars they discuss the material of the lectures.

Students read up for lectures, and seminars at the library or at home. They work hard, so they have little free time. But when they have it, they try to amuse themselves somehow: they listen to music, watch TV, read books, visit their friends, and go to the theatre or to the cinema. They also go in for sports.

In conclusion I'd like to say that student’s life is very important and interesting.