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The Islamic University of GazaFaculty of Engineering

Civil Engineering Department

Environmental Engineering(ECIV 4324)

Instructor: Dr. Abdelmajid NassarLect. 29-31

Solid Waste Management

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Types of Solid Waste

1. Municipal

2. Industrial

3. Hazardous

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Sources of Solid Waste

1. Municipal Waste1. Residential2. Commercial3. Open areas4. Treatment Plant Sites

2. Hazardous

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3. Moisture content (%) =( )*100

Where a = initial mass of sample as deliveredb= mass of sample after drying

Physical Composition of Solid Waste

1. Individual Components

2. Particle Size

4. Density

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Sampling Procedure

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Chemical Composition

energy content

kJ/kg (dry basis )= kJ/kg (as discarded)

kJ/kg (ash-free dry basis )= kJ/kg (asdiscarded)

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Chemical Composition

energy content

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Chemical Composition

Chemical content

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Chemical Composition

Chemical content

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Example

Component Percent Moisture ContentFood Waste 15 70Paper 45 6Cardboard 10 5Plastic 10 2Garden trimmings 10 60Wood 5 20Tin Cans 5 3

100 79

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Chemical Composition

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Waste management is the collection, transport, processing, recycling or disposal and monitoring of waste materials.

The two conventional principles of waste management were: ‘Dilute and disperse’ or ‘concentrate and contain’.

The main necessity of waste management is to enrich the resources which are being depleted due to rising population and increasing consumption rates.

Management

HEALTH IMPACTS OF SOLID WASTE

Exposure to hazardous waste can affect human health, children being more vulnerable to these pollutants.

Improperly operated incineration plants cause air pollution and improperly managed and designed landfills attract all types of insects and rodents that spread disease.

Direct handling of solid waste results in chronic diseases with the waste workers and the rag pickers being the most vulnerable.

WASTE MINIMISATION

Prevention of waste being created is known as waste

reduction which is an important method of waste

management.

The modern concepts based on the three ‘R’s are: Reduce,

Reuse and Recycle.

Methods of avoidance include reuse of second hand

products, designing products to be refillable or reusable,

repairing broken items instead of buying new etc.

HIERARCHY OF

WASTE MINIMIZATION

WASTE COLLECTION

From individual houses, wastes can be collected in person

with the help of vehicle.

To minimize the time and cost involved in collecting waste

through vehicles, public can be given instruction to dump

their house wastes in one place (nearby their street).

SEGREGATION

Segregation of wastes into degradable and non-degradable wastes is to be done to recover or divert non-degradable wastes (electric items, plastics, tyres etc.) and degradable items (wood, textiles etc.) to its recycling plant and if possible, it can be reused.

It is a tedious process which therefore needs labour. Magnets can also be used to segregate ferrous metals.

This process will help in reducing the amounts of waste going for composting and also earns money (through selling wastes to recycling plant.

RECYCLING

The non-degradable and degradable wastes can be

recycled very economically in the recycling

plants.

Apart from sending wastes to recycling plant, recycling of

some organic waste is possible.

Some of the waste recycling techniques are: Fly ash,

Organic wastes, Slag and scrap, Industrial gases,

Waste waters, Recovery of silver from photographic films.

SHREDDING OR PULVERIZING

This process involves in size reduction of organic wastes

before it goes for composting.

This process reduces the overall volume by 40%.

ADVANTAGES:

It will increase surface area availability for bacterial

activity (decomposition).

Facilitates easy handling of moisture content and aeration.

COMPOSTING

Aerobic composting is one of the cheapest and easiest

methods that are being available for MSW.

Generally, composting can be carried out in three

techniques. They are

i) windrow composting

ii) Aerated static pile method

iii) In vessel method