sewage water as the source of irrigation and plant nutrients

8/9/2019 Sewage Water as the Source of Irrigation and Plant Nutrients

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SEWAGE WATER AS THE SOURCE OF IRRIGATION AND PLANT NUTRIENTS

INTRODUCTION Supplies of good quality irrigation water are expected to decrease in future because the development of new water resources will not keep pacewith increasing water needs of agriculture, industries and municipalities. some of these future water needs can be met by using available water supplies more efficiently but in many cases it will be necessary to make increased use of municipal waste waters and agricultural drainage water.

agricultural and landscape irrigation can offer significant opportunity for waste water reuse in arid and semi arid regions, since 70-90% of water resources are used for irrigation. In many countries of the world, treated waste water is considered as an important element in water resources

planning. The sewage is a rich source of plant nutrients and other organic wastes.

SEWAGE

Sewage indicates the liquid waste from the community. It includes sludge, discharge from latrines, urinals, stable industrial waste and also the

ground surface and storm water that may be admitted into the sewer. It is extremely putrescible; its decomposition produces large quantities

malodorouse gases and it may contain numerous pathogenic or disease producing bacteria.

TYPS OF SEWAGE

DOMESTIC SEWAGE

It is the sewage obtained lavatory basins, urinals and water closets of residential buildings, office buildings, theatres and other institutions. Sinceit contains human excreta and urine, it is extremely foul in nature.

INDUSTRIAL SEWAGE

It is waste water obtained from the industrial and commercial establishments. it may contain objectionable organic compounds that may not be

amenable to conventional treatment processes. Combination of industrial sewage and domestic sewage together is called sanitary sewage.

STORM SEWAGE

It includes run off resulting from rain fall.

DISPOSAL OF SEWAGE After conveying the waste water through sewers, the next step is its disposal, either after treatment or even before treatment.

METHODS OF DISPOSAL OF WASTE WATER

NATURAL METHOS

By dilution

By land treatment

ARTIFICIAL METHOD PRILIMINARY TREATMENT

PRIMERY TREATMENT

SECONDARY TREATMENT

TERITIARY TREATMENT

DILUTION

The disposal of sewage by discharging it into water courses such as streams, rivers or large body of water such as lake, sea is called dilution.While discharging the sewage in this way care should be taken that the sewage may not pollute the natural water render it unfit for any purposesuch as drinking, bathing, fish cultivation and industrial as well as irrigation uses.

The dilution method of disposing off sewage can be favourably adopted under the following.



When the city is situated near the sea, river or lake etc..

When the sewage is fresh, non-septic and free from floating and setteable solids.

When the volume of receiving water is large enough to take the load of sewage safely without causing it any pollution problems.

When the dilution water has a high dissolved oxygen content(do content)

When the sewage will not cause the dilution of aquatic life and contaminants of shell fish.

BY LAND TREATMENT When the sewage is evenly spread over the surface of the land , the method is called land treatment. The water of sewage perculates in the grown

and suspended solids remains at the ground. The suspended solids remains at the surface of the ground. The suspended solids are acted by the bacteria and are partially oxidized by exposure atmospheric action of heat, height and air. The land treatment can be classi fied as below

FILTRATION

BROAD IRRIGATION

SEWAGE FARMIG

FILRATION AND BROAD IRRIGATION

FILTRATION

Filtration of sewage is by strong action of ground soil and, oxidation and biochemical action of organic matters. The complex compounds of

sewage are converted into the harmless mineral salts which serve as valuable fertilizer. In filtration more depth of soil below the ground leveltaken part in the sewage treatment.

BROAD IRRIGATION

In this method, the sewage is stabilized by aerobic action. In this method under drainage system is laid below ground level to collect the effluentof sewage after filtration through the ground soil.

The under drainage system usually consist of 15cm to 20cm diameter porous pipes which are laid open joined at the spacing of 10-30 cm. The

effluent which is unfoul can be directly disposed off into the water courses.

SEWAGE FARMING When the sewage is used for growing crops, it is called sewage farming. The fertilized elements of sewage are consumed by the root of crops.

The minerals, nitrates, sulphates and phosphates are main fertilizer constituents of sewage. The method in addition to disposing of the sewagemay also help in increasing crop yield by 30% and so.

APPLICATION OF SEWAGE

SURFACE IRRIGATION

In this method the parallel drains are constructed in the fields. All the drains are connected to a distributery drain by means of regulatory devices.

This method is most suitable for dry areas.

SUBSOIL IRRIGATION

In this method a network of porous open joint pipe is laid about 30 cm below the ground level. The sewage is allowed to flow through these pipes, which is absorbed by the subsoil. The remaining quantity of sewage can be used for irrigation to another place or discharged in naturalwater course.

FLOODING , RIDGE AND FURROW



FLOODING

The irrigation area is divided into various parts surrounded by dykes. The sewage is filled like small ponds in between the dykes. The depth of sewage flooded over the fields varies from few centimeters to 50 cm depending upon the requirement of the irrigation.

RIDGE AND FURROW

In this method the land is divided in to plots and sub plots. Now ridge and furrow formed in each sub plots. The sewage is allowed to flow in

furrow where as crops are grown on the ridges.

ADVANTAGES AND DISADVANTAGES OF LAND IRRIGATION ADVANTAGES OF LAND IRRIGATION

The disposal of sewage is done by natural treatment.

The natural water sources are prevented from pollution.

This method is cheaper and dose not requires the sewage treatment plant.

The land is irrigated and helps to increase the crops yield by 30% and so«

DISADVANTAGES OF LAND IRRIGATION

Large area of land is required for this type of disposal work.

During rainy season and in wet climate this method is not

Suitable.

In this method is not properly supervisioned the land may become useless.

In this method disposal attention is to be taken against the spreading of diseases.

This method is not suitable for land consisting of clayey soil.

PLANT NUTRIENTS Nitrogen, phosphorus, and pottasium are often referred to as the primary macronutrients because of the general probability of plants being

deficient in these nutrients and the large quantities taken up from the soil relative to other essential nutrients

EFFECT OF NITROGEN IN PLANTS Of all the essential nutrients, nitrogen is the one most often limiting for crop growth. Many soils contain large amounts of nitrogen, but most of the nitrogen is tied up in the organic fraction and only slowly released. For most non legume crops, some nitrogen fertilizer is required for

adequate yields. Nitrogen is available to the plant in two forms- ammonium (NH4) and nitrate (NO3).In most soils, ammonium is quickly

converted to the nitrate form, a process called nitrification. This nitrate form is not tightly held on soil particles and is soluble in water.Consequently, nitrogen management is important both from a production and environmental standpoint. On sandy soils, nitrogen applied early inthe season can be easily leached out of the root zone with heavy rainfall or excess irrigation. Nitrogen deficiency may result, as well as an

increased potential for nitrate contamination of the ground water.

ADVANTAGES AND DISADVANTAGES OF SEWAGE IRRIGATION

ADVANTAGES OF SEWAGE IRRIGATION

Disposal of waste water are possible.

Irrigation of agricultural lands are possible.

Increased crop yield.

Commercial crops can be easily grown on sewage farms.

Increased percentage of nutrients in soil.

DISADVANTAGES OF SEWAGE IRRIGATION

After continuous applications of sewage on land, the pores of the soil get clogged, preventing oxidation and causing noxious smell. The land is

unable to take any further load of sewage. This phenomenon is called sewage sickness of land.



Increased concentration of heavy metals in soil.

Toxic chemicals and pathogenic micro organisms in untreated waste water have a potential for deleterious health effects and disease transmission.Epidermiological investigations of reuse of raw or minimally-treated waste water for food crop irrigation provided evidence of infections disease

transmission.

CONCLUTION By the controlled sewage irrigation, we can attain both the safe disposal of sewage and increased crop yield. The sewage water provides nutrientsfor the plants which helps in their vegetative growth. However, waste water irrigation should be in optimum level; otherwise the high metal

content will cause health problems and soil sickness.

Reference: http://www.seminarprojects.com/Thread-sewage-water-as-the-source-of-irrigation-and-plant-nutrients-full-report#ixzz0qKXjMchK

sewage water as the source of irrigation and plant nutrients

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