waste disposal.pptx

waste disposal

1. BY- VAISHNAVI SHARMA GUIDED BY- B.D.S. FINA YEAR DR. AMIT TIRTH SIR ROLL NO. 87 DEPARTMENT OF PUBLIC HEALTH DENTISTRY

2. CONTENTS Definition of waste Classification of waste Types of waste disposal Controlled tipping Composting Incineration Manure pits Burial

3. What is waste? Waste is defined as “ any substance or object which the holder discards or intends or is required to discard.”

4. Classification of Waste 1. Based on source of origin a)Household b) Wastewater treatment c) Health care or medical waste d) Agriculture/ forestry e) Industry f) Construction g) Mining 2. Based on nature of waste a) Non-hazardous or solid waste: Organic waste , paper, plastics, metal, glass. b) Hazardous waste: waste causing harm to the environment and human health. - Health care waste - Radioactive waste - E-waste

5. Waste Disposal If waste is left around the disposed in uncontrolled or open dumps the waste is exposed to the files and rodents which is sources of nuisance to environment . The ideal waste management system is satisfied 3 charestistics economical ,environmental and social sustainability . The principal solid waste disposal method are Controlled tipping and sanitary land fill Composting Incineration Manure pits

6. CONTROLLED TIPPING (SANITARY LANDFILL) - Landfills are important part of urban management system. - Three methods are used : a)Trench method : used where level ground is available. A long trench is dug 6-10ft deep and 12-36ft wide. The refuse is compacted and covered with excavated earth. b) Ramp method : used where land is moderately sloping. Some excavation is done to secure the covering material. c) Area method : used for filling land depressions. The refuse is deposited and sealed on its exposed surface with a mud cover.

7. COMPOSTING - Process that optimizes the natural decomposition of food, garden, and agricultural wastes into a fertilizer like product called compost. - Various methods are: a) Mechanical composting ( In vessel composting): It is a mechanical method that controls the temperature and oxygen levels in a composting chamber. The refuse is first cleared with salvageable materials such as rags, bones, metals and other items which interferes in the grinding operation. The waste is crushed into smaller particles. Once it is processed it is allowed to sit outside vessel to complete decomposition. Maturation stage takes 4-6 weeks.

8. b) Bangalore method ( hot fermentation process): Trenches are dug. The pits should be located at least 800m away from the city limits. First a layer of refuse is spread at the bottom of the trench. Nightsoil is added over this. Then alternate layers of refuse and nightsoil are added till the heap rises1 ft above the ground level. Then it is covered with excavated earth and compacted. Within 7 days, compost mass is generated due to bacterial action. At the end of 6 months decomposition is complete.

9. c) Windrow composting - Process where organic waste is placed in a large pile or row (known as windrow) and periodically turned. The mixing process introduces oxygen to promote microbial activity.

10. INCINERATION - It refers to the combustion of waste under controlled conditions. - Incineration applied with energy recovery has the potential to be source of energy in addition to a waste management solution. - Although incineration technology has matured over the last few decades, it is still relatively expensive . However the cost of installing an incinerator can be recovered. - Thus it reduces the volume of the waste, elongates landfill life. The average life span is about 25 years.

11. MANURE PITS they are dug by individual householders to dump the garbage ,cattle dung , straw and leaves. They are covered with earth after each day dumping . In 5-6 month’s time , the refuse in converted into manure. BURIAL A trench excavated and at the end of each day the trench is filled with earth and compacted . Method is suitable in small camps.

12. CONTROLLED TIPPING COMPOSTING INCINERATION

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