Definition of Solid Wastes

8/9/2019 Definition of Solid Wastes

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Definition of solid wastes?

Solid wastes can be broadly defined as those wastes that have been rejected for further use and

which can neither be transported by water into streams nor can readily escape into the atmosphere.

What are solid wastes?

They include all the discarded solid materials from municipal, agricultural and industrial activities.

Characteristics of solid wastes

Composition

Apart from variations in quantity, wide variations in the composition of domestic and municipal solid

wastes may also occur depending on the following factors:

1. Degree of urbanization and industrialization of the area

2. Per capita income

3. Social customs

4. Climatic conditions

5. Acceptability of packaged foods

6. Frequency of collection by the municipality, etc.

Density

The density of municipal solid wastes varies from 150 to 800 kg/m3 depending upon the waste

composition.

Energy content



Municipal solid wastes contain about 50% of combustible matter. Hence the waste is often burnt as

a means of disposal.

Classification of Solid wastes

Solid wastes can be classified into the following five categories:

Domestic wastes

Wastes from household preparation, cooking and serving of food, waste paper and plastics, clothes,etc.

Municipal wastes

Garbage and rubbish from households, offices, hotels, markets, etc. and also the street refuse such

as street sweepings, dirt, leaves, contents of litter receptacles, etc. The term garbage is generally

used to putrescible or biodegradable food wastes. The term rubbish is used to denote

nonputrescible or nonbiodegradable solid wastes which include combustible materials such aspaper, cloth, etc. as well as noncombustible materials such as glass, metals, used metal cans, etc.

Apart from these the following types of wastes are also encountered: ashes, cinders, dead animals,

abandoned vehicles, septic tank sledges, etc.

Industrial wastes

1. Nonprocess wastes such as office and cafeteria wastes, packing wastes, etc. which are

common to all industries.

2. Process wastes which depend upon the type of the products being manufactured such as

tannery wastes, weaving and dying wastes, rubber wastes, etc. from the respective industrial

establishments.

Agricultural wastes



These wastes result from farms, feed lots and livestock yards. The agricultural wastes include paddy

husk, bagasse from sugarcane, tobacco and corn residues, etc.

Special wastes

These include hazardous wastes from different sources

1. Radioactive wastes: nuclear power plants, hospitals, etc.

2. Toxic wastes: heavy metal sludges, pesticides, pharmaceuticals, etc.

3. Biological products: enzymes, antibiotics, pathological wastes, etc.

4. Miscellaneous products: inflammable substances, explosives, etc.

How to manage solid wastes?

The major considerations of concern with solid waste management apart from economics are:

1. Public health

2. Waste separation for recycling

3. Energy recovery

4. Generation of useful byproducts

Solid waste management comprises of purposeful and systematic control of the generation, storage,

collection, transport, separation, processing, recycling, recovering, and disposal of solid wastes. It isalso aimed at doing so economically with the protection of public health.

The most commonly used solid waste treatment and disposal methods are composting, sanitary

landfills or controlled tripping. Thermal processes and recycling.



Slide 1:

SOLID WASTES DISPOSAL Dr. D. Praveen Postgraduate DEPARTMENT OF COMMUNITYMEDICINE

OSMANIAMEDICAL COLLEGE HYDERABAD

Slide 2:

INTRODUCTION Proper disposal of solid waste is necessary because it may contain health hazard

materials. Correlation between improper disposal of solid wastes and incidence of vector-borne

diseases. An efficient system for its periodic collection, removal and final disposal without risk to

health. Health professionals may call for camp sanitation or coping with waste disposal problems

when there is a disruption or breakdown of community health services in natural disasters.

Slide 3:

What is Solid Waste ? Solid wastes includes Garbage (food waste) Rubbish (paper, plastics, wood,

metal, throw-away containers, glass) Demolition products (bricks, concrete, pipes) Dead animals,

manure and other discarded materials.

Slide 4:

SOLID WASTE ACCUMULATION, A HEALTH HAZARD BECAUSE : It decomposes and favours fly

breeding It attracts rodents and vermin The pathogens which may be present in the solid waste may

be conveyed back to mans food through flies and dust There is a possibility of water and soil

pollution Heaps of refuse present an unsightly appearance and nuisance from bad odour.

Slide 5:

SOURCES OF REFUSE (SOLID WASTE) Street refuseMarket refuse Stable refuse (litter) Industrial

refuse Domestic refuse

Slide 6:

STORAGE Galvanized steel dust bin with close fitting cover. Public Bins COLLECTION House to house

collection. Dumping the refuse into the nearest public bins. Thrown in the street. TRANSPORT

Dustless refuse collector (vehicles) - Western method

Slide 7:





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c) Incineration : Refuse can be disposed of hygienically by burning or incineration. It is a method of

choice where suitable land is not available. Hospital refuse which is hazardous is best disposed of by

this method.

Slide 15:

DIFFERENT TYPES OF INCINERATORS :

Slide 16:

d) Composting :Method of combined disposal of refuse and night soil. Two methods Bangalore

Method (Anerobic method) Hot fermentation method Mechanical composting (Aerobic method)

Slide 17:

COMPOSTING : BangaloreMethod

Slide 18:

e.Manure pits Refuse is disposed in rural areas by digging manure pits in the individual house

holds. f. Burial This method is suitable for small camps.

Slide 19:

GOBAR PITS :

Slide 20:

PUBLIC EDUCATION : Public cooperation is needed for collection of solid waste disposal. Public

awareness is created by using mass media like radio, TV, newspaper, etc.

Slide 21:

ECONOMICS AND FINANCE Financing is usually done by municipalities and gram panchayats About

20% of the municipal budget is spent on collection and disposal of solid waste. INTERNATIONAL

COOPERATON ISWA (International Solid Waste and Public Cleansing Association) 1970. This is

assisting countries to improve sanitary services. WHO International reference centre (Switzerland) -



helps to collect, evaluate and disseminate information on waste disposal practices and to foster

research.

Slide 22:

SUMMARY Solid Waste is hazardous to health so it has to be handled carefully and disposed

properly in order to protect our health and to maintain good environment.

Slide 23:

REFERENCES Parks Textbook of Social & Preventive Medicine. Internet sites

Documents

Definition of Solid Wastes