Waste disposal

MOHD. TARIQUEP.G. SCHOLARDEPARTMENT OF TAHAFFUZI WA SAMAJI TIBNATIONAL INSTITUTE OF UNANI MEDICINE ,KOTTIGEPALYA, MAGADI MAIN ROAD, BANGALORE- 91

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Garbage on a city street

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Contents

Solid waste disposal Human waste disposal

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Solid waste disposal

Solid waste includes food waste, paper, plastics, wood, metal, glass, bricks, concrete and any discarded material

Usually human excreta is NOT included in this

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A person walking through garbage searching for useful things

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Health hazards of waste

Fly breeding Attracts rats Soil and water may get contaminated Produces bad smell Bad to look at

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Methods of disposal

Burning/incineration Dumping Controlled tipping Composting

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Burning/incineration

All combustible material can be burned Materials like glass, metal, concrete will

not burn Hospital waste is burned in incinerators

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Dumping

A simple method is to dump the waste in low lying areas

It will fill the area and the waste will over a period of time turn to manure (السماد)

However open dumping will attract birds, flies, rats etc.

Must be done far away from the cities

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Controlled tipping

Is a good method Pits or trenches are dug and one layer of

waste is deposited and is covered with earth.

Then another layer is added till the pit is filled

Over a period of time the waste will turn into manure

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Composting

Is a method of combined disposal of waste and human feces

A pit or trench(خندقه) is dug A layer of human feces is spread and over it a

layer of waste is spread and then human excreta and so on till it reaches the surface level

A final layer waste is added and covered with earth.

After 4-6 months it will be converted to manure

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Cross section of compost pit

Soil

Garbage

Human excreta

Garbage

Human excreta

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Disposal of human excreta

Human excreta is infected material containing many pathogenic organisms

Contamination of soil, water and food can lead to many diseases

‘Sewage’ is waste water containing human excreta and industrial wastes

Sewage is taken to treatment plants to make it safe

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Important stages of purification of sewage are: Filtration – to remove large solid waste like

stones, glass, metal pieces etc. Primary sedimentation Aeration and oxidation Secondary sedimentation

Sometimes untreated sewage is directly discharged into sea

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Pictorial representation of a sewage treatment plantPrimary Sedimentation

Secondary Sedimentation

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Sewage treatment

The effluent is harmless and can be used for irrigation

The sludge can be disposed of by composting or dumping

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Excreta disposal in ‘unsewered’ areas – villages, small settlements Pit latrines – for temporary camps/emergencies

A large pit is dug and people defecate into it. When it is 2/3rd full it is covered with earth and a new

pit is dug

Septic tanks – for individual homes, public latrines

Chemical toilets – used in planes and boats- Excreta is sterilized by the chemical and disposed off

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Pictorial representation of septic tankAnaerobic digestionAerobic

oxidation

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Summary

Garbage and human excreta have to be disposed off properly to prevent health hazards

Garbage can be disposed off by – dumping, controlled tipping and composting

Human excreta can be disposed by sewage treatment on a large scale

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Summary

Other safe methods of disposal of human excreta are – septic tank, pit latrine and chemical toilets

It is very important to keep the environment clean to prevent diseases and keep the community healthy

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