Waste Disposal

DISPOSAL OF WASTES

SOLID WASTE • Solid wastes include garbage, rubbish, glass demolition products, sewage treatment residue, dead animals, manure & other discarded material.

TYPES OF REFUSE • • • • •

STREET REFUSE MARKET REFUSE STABLE REFUSE INDUSTRIAL REFUSE DOMESTIC REFUSE

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Refuse stored in “ galvanized steel dustbins with close fitting cover”.

• Best method of collection is “ House to house collection”.

Methods of Disposal 1) Dumping : easy method of disposal. 2) Controlled dumping : a) trench method b) ramp method c) Area method 3) Incineration : method of choice when suitable land is not available. Hosp refuse is best disposed by this method.

4) Composting : combined method of disposal of refuse and night soil. a) Bangalore method (anaerobic method) b) Mechanical composting (aerobic) 5) Manure pits : 6) Burial :

OXIDATION POND Cheap method of sewage treatment. is an open, shallow pool 1 to 1.5m deep with an inlet and a outlet. Following should be present– a) Algae b) Certain types of bacteria c) Sunlight

• the organic matter contained in the sewage is oxidised by bacteria to simple chemical compounds such as carbon dioxide, ammonia & water. • Algae with the help of sunlight utilize these materials for their growth, thus there is a mutually benificial oxygen balance between algae & bacteria.

• oxidation ponds are predominantly aerobic in sunshine & in some hours in the night. • in the remaining hours bottom layers are anaerobic. • So the sewage purification in oxidation ponds is brought about by a combination of aerobic & anaerobic bacteria.

sun

Wind O2 ALGAE

Rain wastes

SETTLEABLE SOLI DS

CO2

OXYGEN

BACTERIA

THANKYOU