Garbage disposal
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Solid waste management involves the collection, transport, and disposal of garbage, trash, and other waste materials. Waste is categorized as biodegradable or non-biodegradable and is collected from residential, commercial, institutional and other sources. It is transported to disposal sites using municipal trucks. Traditional disposal methods include landfilling and incineration, though landfilling in sanitary landfills that prevent pollution is preferred. Other organic waste treatments include composting and biogas production. Reducing, reusing, and recycling materials helps minimize waste and environmental impacts.
Garbage disposal
- 1. Solid Waste disposal a. Collection, treatment and disposal of organic and inorganic waste, like traditional methods, garbage chutes, urban solid waste treatment systems, vermi composting etc.
- 2. Solid Waste • Commonly known as Trash, Garbage, refuse or rubbish • everyday items that are discarded by the public. • Solid waste can be defined as non liquid material that no longer has any value to the person who is responsible for it • The composition of municipal waste varies greatly from country to country • Garbage generate at different levels – Domestic, commercial, industrial, healthcare, agriculture activities. • Waste from houses, streets, shops, offices, industries and hospitals are usually considered to be responsibility of Municipality or local government to remove and dispose in environment friendly manner • If solid wastes are not managed properly, it would result in insanitary conditions, diseases threatening public health
- 3. Effect of solid waste in recent years • Cloud burst in Mumbai (2005) clogged the sewage lines due to large no. of indisposed plastic bags. • Plague epidemic in Surat (1996) caused majorly due to indisposed solid waste present within city • Reduction in Bird migration • Death of birds/animals due to consumption of plastic bags and contaminated food • Reduction of cultivable land
- 4. For efficient solid waste, waste are categorized in two types Bio-degradable materials: • food and kitchen waste, green waste, paper, food and green waste (can also be recycled). Non Bio-degradable materials: • Recyclable material: paper, glass, bottles, cans, metals, certain plastics, fabrics, clothes, batteries etc. • Inert waste: construction and demolition waste, dirt, rocks, debris. • Electrical and electronic waste (WEEE) - electrical appliances, TVs, computers, screens, etc. • Composite wastes: waste clothing, Tetra Packs, waste plastics such as toys. • Hazardous waste including most paints, chemicals, light bulbs, fluorescent tubes, spray cans, fertilizer and containers • Toxic waste including pesticide, herbicides, fungicides • Medical waste.
- 5. Sources and Types of Municipal Solid Waste Sources Typical waste generators Components of solid waste Residential Single and multifamily dwellings Food wastes, paper, cardboard, plastics, textiles, glass, metals, ashes, special wastes (bulky items, consumer electronics, batteries, oil, tires) and household hazardous waste Commercial Stores, hotels, restaurants, markets, office buildings Paper, cardboard, plastics, wood, food wastes, glass, metals, special wastes, hazardous wastes Institutional Schools, government center, hospitals, prisons Paper, cardboard, plastics, wood, food wastes, glass, metals, special wastes, hazardous wastes Municipal services Street cleaning, landscaping, parks, beaches, recreational areas Street sweepings, landscape and tree trimmings, general wastes from parks, beaches, and other recreational areas
- 6. Solid Waste Management Solid Waste Management: Systematic well planned and well managed control on generation, collection, storage, transport, source separation, processing, treatment, recovery and disposal of solid waste. Resource recovery is the selective extraction of disposed materials for a specific next use, such as recycling, composting or energy generation. The aim of the resource recovery is to extract the maximum practical benefits from products. Solid waste can be divided into three sections • Collection of solid waste • Conveyance of solid waste • Disposal of solid waste
- 7. Collections of Solid Waste • Collection of solid waste from individual premises to the community level. • Waste must be segregated at the source by collecting separately to facilitate recycling of both types of solid wastes - bio-degradable and non bio-degradable • There are several ways to collect and transport waste for disposal
- 8. Garbage Containers They are available in many sizes • Dust beans for office and domestic used – Are designed for easy handling – Available in different sizes generally 300mm diameter – Most of them are covered with lid – Made of plastic or metal • Garbage Cans for building or apartment – Are bigger in size generally 450x450 or 600x600mm – Wheeled end with handle for easy handling – Usually made out of plastic and metal • Waste container for community or neighborhood level – Are still bigger in size 1200x1800 or 1500 x 2100 – Made of metal or plastic – Special handles will be provided so that vehicles will automatically lift and empty the container in the truck or replaced with the container loaded on the truck.
- 9. Kitchen sink with waste receiver • Kitchen sink with garbage system • A waste receiver is fitted below the sink where kitchen wastes are allowed to be collected • When the container is filled up, it is flushed to the waste water pipe of larger diameter (150mm) or manually taken away for vermi composting • Maintenance cost is high
- 11. Kitchen Sink with Grinder • A waste container with the electric grinder is fitted below the sink, so the kitchen waste are reduced to smaller size particles for easy washing • This is not suitable for bulky refuse
- 13. Conveyance of Solid Waste • Usually Conveyance of solid waste starts at individual house or neighborhood level • The dumping places for waste are located away from the city • Municipal trucks are used to carry wastes collected from community collection points • Wastes are necessary to be removed as fast as possible after generation in order to prevent degrading of environment
- 17. REFUSE (Garbage) CHUTES Conveyance within Multi-storeyed Buildings • Refuse chute system built in multi- storeyed residential buildings for transporting and collecting the refuse from flats at different heights. • The refuse is received from the successive flats through the inlets located on the vertical system of pipes that convey refuse through it and discharges into the collecting chamber from where the refuse is cleared at suitable intervals. • Components of garbage chute are, the inlet hopper (flap opening), the collection chamber (wheel container is placed in a chamber for collection of waste for periodic removal) and vent at top.
- 18. Main Components • Chute—A vertical pipe system passing from floor to floor provided with ventilation and inlet openings, for receiving refuse from successive flats and ending at the ground floor on the top of the collecting chamber. • Inlet Hopper—A receptacle fitting for receiving refuse from each flat and dropping it into the chute. • Collection Chamber—A compartment situated at the lower end of the chute for collecting and housing the refuse during the period between two successive clearings.
- 19. CHUTES Number of Chutes— The number of chutes depends upon – the convenience to the user and – the quantity of refuse to be handled between two subsequent clearings. Material of Construction— Chutes may be constructed out of – asbestos cement, – R.C.C. Pipe or – Stainless steel with smooth inside finish. Diameter of the Pipe— Chutes shall be of a minimum internal diameter of 380mm Finish— The inside surface of the chute-should be finished as smoothly as possible so as not to allow any sticking of refuse particle that may cause choking eventually.
- 20. • Location— – The chute may be carried through service shafts meant for carrying drainage pipes. – The location shall be mostly determined by the position of inlet hopper and the collecting chamber that is most convenient for the user. – It should also be considered to locate the chute away from living rooms in order to avoid noise and smell nuisance. • Construction— – The chute pipes should be assembled vertically, and-properly clamped to the wall. – The joints should be of cement mortar arid the chute may be squarely embedded into the surrounding walls. • Ventilation— – Natural ventilation should be adequate to prevent any possible odour nuisance. – The upper end of the chute, that is, beyond the uppermost floor should be provided with a ventilation pipe to the full bore which should rise 2 to 2.5 m above the roof or terrace of the building. – An umbrella type cowl with wire mesh at the top will be helpful to prevent rainfall and other external objects of nuisance potential. – For high rise buildings mechanical ventilation of the exhaust type is recommended.
- 21. Chute Maintenance • Access—Each chute pipe should be provided with an access door-at intervals not greater than every third floor. • Wrapping of Refuse—To help preventing spillage and blockage, the residents should be encouraged to wrap their refuse. • Flushing of Chute—Y-connection at terrace level may preferably be provided in order to direct a water hose for cleaning purposes, if needed.
- 22. INLET HOPPER • Location— – In individual chute system, the inlet hopper shall be located in the passage near the kitchen and in the common chute system towards the end of the common passage. – There should be adequate lighting at this location. – Inlet Hopper shall be located 750mm above floor level – For ground floor flats the inlet hoppers may be placed at a higher level and a flight of steps may be provided for using the same.
- 23. • Design and Construction— – Hopper shall be constructed such that there should be minimum escape of odour or any other vapour when the hopper door is kept open – The hopper flap shall not open inside the chute pipe which might obstruct refuse coming from the top. – The door and the frame should be fire- resistant. – Size of the Mouth and Throat—The mouth shall have a maximum size of 25 cm height and 36 cm width. The throat should not be less than the size of the mouth. The diagonal of the mouth should not be larger than the chute size. – Height of the Hopper—The hopper should be constructed at a height of 75 cm measured from the floor level to the lower edge of the inlet opening. – Inner Surface—The interior of the hopper should slope towards the main chute at an angle not less than 45° to 60 ° to the horizontal for better performance. The inside finish should be as smooth as possible.
- 25. COLLECTION CHAMBER Location— • The collection chamber shall be situated at ground level. Capacity— • If the refuse is discharged directly on the floor of the collection chamber, the capacity is designed on the quantity of refuse expected from the chute between two consecutive clearings. • It may be recommended to provide a minimum capacity of 0.054 m3/family or apartment per day. • In the case of chutes serving small number of apartments, the minimum size of the collection chamber shall be 1.2 × 1.2 × 1.8 m in order to facilitate providing trolley and easy cleaning of the chamber. • Normally the height of chute bottom above the top of the container shall be about 30 cm in order not to allow any refuse to spill on the floor of the chamber. • It will be preferable to provide a minimum head room of 2 m for the collection chamber to facilitate easy entry into it.
- 26. Disposal of Solid Waste • This is the most important part of the system which requires maximum attention • Solid waste is dropped in a location with arrangements to segregate waste for recycling and reuse • Methods of Disposal – Landfill : Open dump and Sanitary Landfill – Incineration – Ocean Dumping
- 27. Traditional methods: Landfills • There are two basic types of landfills Open dumping and Sanitary Landfill • Open Dumping – Very Cheap and convenient – Requires more land which would become unfit for habitation – Unsanitary, draws pests and vermin, harmful runoff and leachates , toxic gases – Still accounts for half of solid waste • Sanitary Landfills – Layer of compacted trash covered with a layer of earth once a day and a thicker layer when the site is full – Require impermeable barriers to stop escape of leachates: can cause problem by overflow – Gases produced by decomposing garbage needs venting – Cheap and convenient than any other disposal other than open dumping. – Requires more land which would become unfit for habitation
- 29. Incineration • Wastes are burn down • Incinerations can be manually and electrically operated Advantages: • Reduces the land requirement • Reduce volume 90%, weight 75% • Heat from burning converted to electricity Disadvantages: • Hazardous waste like Hospital wastes are incinerated • produces toxic gases like Cl , HCl , HCN, SO2 • High temp furnaces break down hazardous compounds but are expensive • Concentrates toxins in ash • More costly than landfills, as long as space available There are basically two types of Incineration 1. Refuse-Derived Fuel - Refuse is sorted to remove recyclable and unburnable materials. – Higher energy content than raw trash. 2. Mass Burn - Everything smaller than major furniture and appliances loaded into furnace. – Creates air pollution problems.
- 30. Ocean Dumping • Out of sight, free of emission control norms • Contributes to ocean pollution • Can wash back on beaches, and can cause death of marine mammals • Preferred method: incineration in open sea • Ocean Dumping Ban Act, 1988: bans dumping of sewage sludge and industrial waste • Dredge spoils still dumped in oceans, can cause habitat destruction and export of fluvial pollutants
- 31. Organic Waste Disposal • Composite Pit / Vermi compost: • Bop gas Plant
- 32. Composite Pit / Vermi compost: – Vermi compost is a rich organic medium consisting of nutrients, plant growth promoting substances, and beneficial micro organisms necessary for plant growth. – It is made from agricultural waste and the use of earthworms. – By using a layered process over a period of time, an organic medium is derived that reduces the need for large amounts of pesticides and even fertilizers.
- 33. Bio Gas Plant • Organic waste (night soil, animal dung, agro) are converted into Fuel gas and manure • The bio gas plant is consists of 2 components a digester and a gas holder • Digester is a cube shape or cylindrical water proof container with an inlet and outlet • The gas holder is normally floating, collects the gas and supplies through a gas outlet • The outlet of digester leads the sludge out into a pit for drying to make manure • There are basically two types of Bio gas plants – Floating gas holder type bio gas plant and – Fixed dome type bio gas plant
- 34. Floating gas holder type Bio Gas plant
- 35. Fixed dome type Bio Gas Plant
- 36. Advantages and Disadvantages • In Floating gas holder type of plant, the floating chamber is made of stainless steel, this is expensive and needs continuous maintenance and supervision for non rust. This dose not arise in the fixed holder type biogas plant as everything here is made of concrete • Fixed dome type biogas suffers from a disadvantage that its volume is fixed, so if the gas pressure increases inside, it may cause damage to the concrete dome. This dose not happens with floating holder type of bio gas plant
- 37. Inorganic waste Disposal • Reduce • Reuse • Recycle
- 38. Reduce & Reuse • Most fundamental method of reducing waste is to prevent it from being produced (Waste Prevention). • Reusing the unwanted waste reduce the waste generated at the source • Advantages of Reduce and reuse at Individuals and Industry level – Saves natural resources. – Reduces waste toxicity – Reduces costs
- 39. Recycling Recycling benefits are • Resource conservation • Pollution reduction – Crushed glass reduces energy required to manufacture new glass by 50%. – One Sunday edition of N.Y. times consumes 62,000 trees. – Only 40% of North American paper is recycled. – Over 60% of aluminum cans recycled. • Saves money, raw materials, and land. • Encourages individual responsibility. • Reduces pressure on disposal systems. – Japan recycles about half of all household and commercial wastes. • Lowers demand for raw resources. • Reduces energy consumption and air pollution
- 40. What we can do? • Buy durable items and repair them • Buy recycled goods and recycle them • Buy beverages in refillable containers • Rechargeable batteries • Reduce junk mail • Lobby for trash separation and recycling • Choose items with minimal packaging & reduce number of bags used • Compost yard and food waste