Month: June 2018

6 Types of Trap Classification According to Shape and Use

Types of Trap

The trap is classified in the following two ways

1. According to shape:

P-trap
Q-trap
S-trap

2. According to use:

Floor trap
Gully trap
Intercepting trap

According to the shape and size traps are classified into 6 types, which are described below:

1. According to shape

According to shape, trap are three types, They are described below

6 Types of Trap Classification According To Shape and Use

a) P-trap

This trap has the shape of letter P. The legs of the trap are at right angles to each other. It essentially consists of a U-tube which retains water acting as a seal between the foul gas and the atmosphere.

b) Q-trap

This trap has the shape of the letter Q. The legs of the trap meet at an angle other than a right angle. It essentially consists of a U-tube which retains water acting as a seal between the foul gas and atmosphere.

c) S-trap

This trap has the shape of letter S. The legs of the trap are parallel. It essentially consists of a U-tube which retains water acting as a seal between the foul gas and atmosphere.

2. According to Use

According to use trap are three types, They are described below

a) Floor Trap

A floor trap is generally made of cast iron. This trap is usually placed on the floor of rooms, kitchens, sinks, bathrooms, etc to admit wastewater into the waste pipe. A cover with grating is provided at its top to prevent the entry of solid matters. The cover can be removed for cleaning of the trap this trap is also known as nahni trap.

b) Gully Trap

A gully trap is generally made of stoneware. A cast-iron grating is provided at its top to prevent the entry of coarser materials. The cover can be removed for cleaning of the trap.

Gully trap is provided at the junction of a room or roof drain and the other drain coming from bathrooms, kitchens, etc.

c) Intercepting trap

An intercepting trap is often provided at the junction of a house sewer and municipal sewer. This trap prevents the entry of foul gases from the municipal sewer into the house sewer.

Intercepting trap is often provided in a small manhole. it also contains an inspection arm for the purpose of cleaning and inspection. This trap is also known as an interceptor or disconnecting trap.

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9 Requirement Of A Good Trap

Factors Affecting The Quantity Of Sanitary Sewage

Active Sludge Process With Advantages & Disadvantages

What is Sanitary & Storm Sewage, Dry And Wet Weather Flow

What is Trap And Their Location and Function

What is Trap

A trap is a sanitary fitting provided at the end of a soil pipe or waste pipe to prevent the passage of foul gases through it. The efficiency and effectiveness of a trap depend upon the depth of the water seal maintained by the trap. This water seal generally varies from 25 mm to 75 mm.

Function Of Trap

In a drainage system, the function of a trap is to prevent the passage of foul gases through it. But at the same time, it allows the sewage to flow through it. Thus, the installation of a trap avoids nuisance.

Location Of Trap

The trap is located in the following manner:

1) Location of Gully Trap

This trap is provided at the junction of a room or roof drain and the other drain coming from bathrooms, kitchens, etc.

2) Location of Floor Trap

This trap is generally placed in the floor of rooms, kitchens, sinks, bathrooms, etc. to admit waste water into the waste pipe.

3) Location of Intercepting Trap

An intercepting trap is often provided at the junction of a house sewer and a municipal sewer.

4) Location of Master Trap

This trap is provided at the water closet.

Types of Sewer Pipe Joints

9 Requirement Of A Good Trap

A good trap should possess the following quality, 9 requirements of a good trap are described below

It should Provide sufficient water seal.
It should be capable of being easily cleaned.
It should be easily fixable with the drain or pipes.
It’s internal and external surface should be smooth.
It should possess self-cleaning property.
It should be free from any inside projection.
It should be simple in construction.
It should be made of some nonabsorbent material
It should be provided with an access door for cleaning.

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Classification Of Trap

Types of Sewer Pipe Joints

Secondary Sedimentation Tank or Clarifier -Coagulation of sewage

Secondary Sedimentation Tank or Clarifier

It is a rectangular tank constructed with brick masonry. Baffle walls are provided in the tank. to divide it into two chambers. Inlet and outlet pipes with valves are provided on opposite corners.

A sludge removal pipe is provided at the bottom of the tank on both chambers. Very fine suspended particles, present in wastewater, which cannot be removed in plain sedimentation tank, can be removed in the secondary sedimentation tank.

Coagulation of sewage

Sedimentation of sewage can be assisted by adding certain chemicals, known as coagulants.

Coagulants react with colloidal matter in sewage and form flock. The phenomenon of the formation of flock is termed as flocculation.

Commonly used coagulants are alum, chlorinated copperas, lime, ferric sulphate, ferric chloride, sodium silicate etc. Ferric chloride is widely used for sewage treatment on a large scale.

Coagulants are mixed with sewage properly with some devices. The commonly used devices are Flash mixer, Deflector plate mixer, floculator.

The choice of chemical as coagulant depends upon its cost, dosage requirement, degree of treatment required, characteristics of waste, pH value of the waste etc.

Alum is preferred in sewage treatment when iron salts are not available and the wastewater is alkaline in nature. If natural alkalinity is not present, sufficient lime is added for the effective working of alum.

Ferric sulphate is effective in a wider pH range of sewage (pH value 4 – 10). Ferrous sulphate works well when pH value is above 9.

If wastewater is highly alkaline due to the presence of industrial waste, it is cheaper to use large doses of ferrous sulphate than ferric sulphate. Ferric salt reacts quickly but they are corrosive and impart colour.

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Primary Treatment Process of Sewage

Characteristics of Sewage

Method of Ventilation of House Drains

16 Municipal Rules Regulation For House Sewer Connection with the Street Main Sewer

Municipal Rules Regulation For House Sewer Connection with The Street Main Sewer

The following principles and municipal rules are adopted for the efficient drainage system. 16 Municipal Rules Regulation House Sewer Connection are:

1) The lavatory blocks should be so located that the length of the drainage line is minimum. At least one wall of the lavatory block should be an outside wall to facilitate the fixing of soil and vent pipes.

16 Municipal Rules Regulation For House Sewer Connection with the Street Main Sewer

2) For better maintenance and easy repairs, the house sewer pipes should preferably be laid by the side of the building. It should not be laid below building or in walls.

3) All drains and sewer pipes should be aligned straight between successive inspection chambers or manhole. All junctions should be oblique and contained angle should not exceed 45°.

4) The lateral sewer and drains should be laid at sufficient slopes so as to develop self-cleaning velocity.

5) The size of the drain or sewer should be sufficient.

6) To avoid back-flow and inefficient building drainage, the house sewer should be connected to the public sewer in such a way that the outfall level of the house sewer is sufficiently higher than the water level of the public sewer.

7) The plumbing system should contain enough number of traps at suitable points.

8) Intercepting trap should be provided at the junction of house sewer and public sewer.

9) Rainwater from the room or courtyards should not be allowed to mix with house sewage or sullage rainwater pipes should drain out rainwater directly into the street gutters.

10) Sewer joints should be watertight. Highly quality-sewer pipes should be used in the system.

11) The entire drainage system should have proper ventilation arrangement.

12) The layout of the house drainage system should be such that it can be repaired or cleaned easily if necessary.

13) The distance between inspection and gully chamber should not exceed 6 m.

14) If there is a possibility of a surcharge in the sewer under storm condition. all gullies and sanitary fitting should be located above the level of maximum surcharge. If it is not possible, an anti-flood valve should be provided in the manhole nearest to the junction of drain and sewer.

15) Manholes should be provided at each end immediately outside the building.

16) If part of the pipe is laid above the ground, it should be laid on concrete supports.

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Primary Treatment Process of Sewage

Characteristics of Sewage

Secondary Sedimentation Tank or Clarifier

Method of Ventilation of House Drains

Active Sludge Process with Advantages and Disadvantages

The sludge that is obtained by setting sewage in presence plentiful oxygen is termed as active sludge. It is biologically active contains a great number of aerobic bacteria and other microorganisms. It possesses an unusual property to oxidize the organic matter.

Active Sludge Process

When the active sludge is mixed with sewage, the microorganisms multiply rapidly. As a result of solids present in sewage are rapidly oxidized. It also converts the suspended and colloidal matter to settleable precipitate.
Operational Features: The flow diagram of the activated sludge process is given below

The activated sludge process consists of the following operations:

a) Mixing of activated sludge

Some portion of the activated sludge is added to the effluent of the primary clarifier and properly mixed.

b) Aeration

The mixed liquor containing activated sludge and effluent is aerated properly in the aeration tank.

c) Setting in secondary clarifier

After aeration, the mixed liquior is taken to the secondary clarifier. Sludge is allowed to settle in this tank. Settled sludge is the activated sludge. A portion of it is sent for re-circulation. The excess activated sludge is sent to the sludge digestion tank and then to sludge drying beds for further treatment and disposal.

Advantages of activated sludge process

The following are the advantages of the active sludge process:

1) The cost of installation is low.

2) This process requires a small area of land.

3) Loss of head through the treatment plant is comparatively low.

4) There is no fly and odour nuisance.

Disadvantages of the activated sludge process

The following are the disadvantages of the activated sludge process:

1) If there is a sudden increase in the volume of sewage or if there is a sudden change in the character of sewage, there are adverse effects on the working of the process.

2) The cost of operating the process is relatively high.

3) This process is sensitive to certain types of industrial wastes.

4) The wet sludge obtained at the end of the process requires a suitable method for its disposal.

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Primary Treatment Process of Sewage

Under-Sluices And Their Function

What are Under-Sluices or Scouring Sluices?

The under-Sluices are the openings which are fully controlled by gates, provided in weir wall with their crest at a low level. They are located on the same side as the off-taking canal.

Under sluices are also called scouring sluices because they help in removing the silt near the head regulators.

Functions of Under-Sluices

i) Preserve a clear and defined river channel approaching the regulator.

ii) Control the silt entry into the canal.

iii) Pass the low floods without dropping the shutter of the main weir.

iv) Provide greater waterways for floods, thus lowering the flood level.

v) They scour the silt deposited on the river bed above the approach channel.

Design Consideration of Under-Sluices

The silt of the under-sluice pocket is kept at or slightly above the deepest river bed and about 0.9 to 1.8 m below silt of the canal head regulator.

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10 Factors Affecting the Duty of Water || Irrigation Engineering

The following factors affect the duty of water:

10 Factors Affecting Duty of Water || Irrigation Engineering

1. Method and system of irrigation

(i) Furrow method ⇢ high duty
(ii) flood irrigation ⇢ less duty than the furrow system
(iii) Perennial system ⇢ high duty
(iv) Inundation system ⇢ low duty than the perennial system
(v) basin irrigation ⇢ low duty
(vi) Flow system ⇢ low duty
(vii) Lift irrigation ⇢ High duty
(viii) Un-controlled flooding ⇢ low duty
(ix) The duty of water is high for sprinkler and drip irrigation methods, as compared to the surface irrigation method

2. Types of Crops

Different crops need completely different quantities of water. So, the duty of water varies from crop to crop. The crops that need a large volume of water have a lower duty of water than for the crops which need less amount of water.

3. Quality of irrigation water

(i) Harmful salt and alkali content leads to a lower duty of water due to the wastage of a considerable amount of water.
(ii) Fertilizing matter in water increases the duty of the water.

4. Method of Cultivation

If the land is correctly ploughed up to the specified depth and created quite loose before irrigating, the soil can have high water-holding capability within the root zone of the plants. This may cut back the quantity of watering and hence result in a higher duty of water.

5. Time of irrigation

(i) Within the initial stages, the land to be cultivated might, not be properly levelled arid hence more than the required amount of water may be applied, which leads to a lower duty of water.

(ii) The gradual rise of the water table with time because of continuous irrigation will make water accessible in the root zone of the plants, therefore comparatively less amount of water is going to be needed to be applied, which will result in a higher duty of water.

6. Canal Condition

(i) Earthen canal⇢percolation loss is high ⇢which leads to a lower duty of water.

(ii) Lined canal⇢percolation loss will be less⇢hence, the duty of water will be high.

7. The climatic condition of the area

The climatic condition which affects the duty of water is
(i) Temperature ⇢ high temperature ⇢loss of water will be more due to Evapotranspiration ⇢so, low duty.

(ii) Higher wind velocity – loss of water will be more due to evaporation -low duty.

(iii) Humidity⇢high humidity⇢loss of water will be less due to Evapotranspiration⇢so, high duty.

(iv) Rainfall⇢increase in duty

8. Base periods of crops

When the base period of a crop is long, more water may be required so leading to a lower duty of water.

9. The character of soil and subsoil of the canal

(i) Coarse-grained soil⇢ seepage and percolation losses are high⇢so less duty.

(ii) Fined grained soil⇢ Percolation losses are less ⇢so, high duty.

10. Method of assessment

(i) Volumetric method⇢more duty(economical use of water).

(ii)crop rate or area basis⇢less duty(more water to be used).

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Method of Improving Duty of Water

Types Of Irrigation

Different Types Of Irrigation Methos in Details

Types Of Irrigation

Irrigation is mainly of two types:

Surface irrigation
Subsurface irrigation

Different Types Of Irrigation Methos in Details

(1) Surface irrigation

Surface irrigation is defined as the group of water application procedures where water is applied and dispersed over the soil surface either by gravity or by pumping.

This technique is most appropriate to soils with low to moderate-infiltration capacities to lands with the comparatively uniform landscape (slopes less than 3%).

In India, More than seventy-five percent (75%) of irrigated lands is supplied water by surface irrigation methods. Surface irrigation can be further classified into:

(i) Flow irrigation.
(ii) Lift irrigation.

(i) Flow irrigation

If the water is available at a higher level, and if it is supplied to a lower level, by the mere action of gravity, then it’s known as Flow Irrigation. Flow irrigation is further divided into the following two types:

(a) Perennial irrigation
(b) Flood irrigation.

(a) Perennial Irrigation

⇛In the perennial system of irrigation, consistent and persistent water supply is assured to the crops as per the requirements of the crop, throughout the crop period.

⇛In this system of irrigation, water is supplied through canal distribution system taking-off from above a weir or a reservoir.

⇛When irrigation is done by diverting the river runoff into the main canal by constructing a diversion weir or a barrage across the river, then it is called direct irrigation. But if a dam is built across a river to store water during monsoons, so as to supply water in the off-taking channel during periods of low flow, then it is termed as storage irrigation.

(b) Flood Irrigation:

⇛ In this type of irrigation method, the soil is kept submerged and fully flooded with water, so as to cause thorough saturation of the land.

⇛It is commonly practiced in delta regions wherever the stream water level during the flood is sufficiently high to provide water to the land by flow, or partly by flow and partly by lift.

⇛This method of irrigation is also known as uncontrolled irrigation or inundation irrigation.

(ii) Lift irrigation

If the water is lifted up by some mechanical or manual means, such as by pumps, etc., and then supplied for irrigation; then it’s known as Lift irrigation. Utilization of wells and tube wells for providing irrigation waterfall under this category.

(2) Sub-surface Irrigation:

In this kind of irrigation system, water does not actually wet the soil surface rather it flows underground and nourishes the plant roots by capillarity. Sub-Surface irrigation can be further classified into:

(i) Natural sub-irrigation
(ii) Artificial sub-irrigation.

(i) Natural sub-irrigation

⇛ Leakage water from channels is going underground and all through passage via the sub-soil, it can irrigate crops, sown on lower lands, via capillarity. Sometimes leakage causes the water table to rise up, which facilitates in irrigation of crops by capillarity.

⇛ When underground irrigation is achieved, absolutely via natural processes without any additional more efforts, it is referred to as natural sub-irrigation.

(ii) Artificial sub-irrigation

⇛ When a system of open jointed drains are artificially laid below the soil, so as to supply water to the crops with the aid of capillarity, then it is known as artificial sub-irrigation. It is a very costly method and for this reason, followed on a totally small scale.

⇛ This method may be adopted only in some special cases with favourable soil conditions and for cash crops of very excessive return.

ILL-EFFECTS OF IRRIGATION

5 Way To Improve Soil Fertility

Advantages And Disadvantages of Irrigation

Advantages of Irrigation

The following are the direct and indirect advantages of irrigation:

Direct advantages of Irrigation

Following are the 4 types of direct advantages of irrigation:

(i) Increase in Food Production

Irrigation improves the yield of crops, which leads to an increase in food production, thus developing people as well as society.

(ii) Revenue generation

When a consistent supply of water is guaranteed for irrigation, the cultivators can grow certain predominant or expensive crops(like cash crops) instead of substandard or low price crops. In this manner, income is created.

(iii) Protection against drought

The provision of adequate irrigation facilities in any region ensures protection against the failure of crops from famine or droughts.

(iv) Mixed cropping

Means sowing of at least two types of crops together in a similar field. This practice is followed so that if climate conditions are not good for one crop it might be reasonable for other crops. But if irrigation facilities are made available, the need for mixed cropping is eliminated:

Indirect advantages of Irrigation

The following are the 4 types of indirect advantages of irrigation:

(i) Power generation

Major river valley projects are generally planned to generate hydroelectric power together with irrigation. However, comparatively, a small quantity of hydroelectric power might also be generated at a small cost on projects which are primarily planned for irrigation.

(ii) Transportation

The irrigation canals are provided with unsurfaced roads primarily for purposes of inspection and maintenance. These roads give a decent pathway to nearby people. The network of irrigation canals can be used for the transportation of goods as well as human beings.

(iii) Groundwater table

In areas where irrigation facilities are provided, due to constant percolation of a portion of the water flowing in the canals and also that is supplied to the field, the groundwater storage is increased and consequently, the groundwater table is raised.

(iv) Employment

During the construction of irrigation works, employment is provided.

Disadvantages of Irrigation

1. The enormous supply of irrigation water tempts the cultivators to use more water than required. Due to excess water supply to the field, water percolates into the soil. Hence, due to the constant percolation, the groundwater table would be raised and will prompt waterlogging.

2. The groundwater can get polluted due to seepage of the nitrates (applied to the soil as fertilizers) into the groundwater.

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Under-Sluices And Their Function

ILL-EFFECTS OF IRRIGATION

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