Solid waste management

INTRODUCTION TO SOLID WATSE MANAGEMENT IMPORTANCE OF SOLID WASTE MANAGEMENT QAUNTITY,COMPOSITION AND CHARACTERISTICS OF DOMESTIC AND MUNICIPAL SOLID WASTE METHODS OF SOLID WASTE COLLECTION SOLID WASTE TREATMENT – COMPOSTING, INCINERATION etc.

WHAT IS SOLID WASTE? Any discarded item; things which are destined for reuse, recycle or reclamation. Based up on the composition it is divided in to two groups: (1) combustible or organic solid waste (2) noncombustible or in organic or mineral solid waste The kind, composition and sources of these solid wastes is tabulated as follows:

Kind Composition Sources Garbage Wastes from preparation, cooking and serving food, market wastes, wastes from handling, storage and sale of products Households, restaurants, institutes, stores and markets Rubbish Combustible: paper, cartons, boxes, barrels, wood, tree branches, yard trimming, wooden furniture Non combustible: metals, tin cans, metal furniture, dirt, glass, minerals Households, restaurants, institutes, sores and markets Ashes Residues from fires used for cooking and heating, on site incineration Street refuse Sweeping, dirt, contents of litter receptacles, leaves, catch basin dirt Street, sidewalks, alleys, vacant lots Dead animals Cats, dogs, deer, rats Abandoned vehicles Unwanted cars and trucks left on public property Industrial wastes Food processing wastes, boiler house cinders, metal scrap, shavings Factories, power plants Demolition waste Pipes, rubber caps, bricks, masonry Renewal projects, demolition site to be used for new building, expressways Construction waste Scrap lumber, pipe, other construction materials New construction, remodeling Special wastes Hazardous solids and liquids, explosives, pathological waste, radioactive waste Households, hotels, hospitals, industry, stores Sewage treatment residues Solids fro screening and from greet chambers, septic tank sludge Sewage treatment plants, septic tanks

Composition of MSW in India

Based on the above table the solid waste is categorized in four types: Municipal waste 2. Industrial waste Agricultural and animal waste 4. Hazardous waste

WHY IT IS IMPORTNANT TO MANAGE SOLID WASTE? The roots of the solid waste problem started from the 20th centaury due to (1) industrial revolution & (2) Technological development Important aspect of environmental sanitation.

Solid waste disposal creates a problem primarily in densely populated areas. The more concentrated population, greater the problem. For instance, U.S. generated around 214 teragrams (TG) of solid waste in 2003, which is 56% more as compare to 1980 and 170% more than 1960. thus the magnitude of solid waste problem is very serious.

Another problems which created from solid waste are: Insects Rats and other vertebrates vectors Fire Odor, When the stink persist all the day and night it causes a major environmental nuisance. illness to the workers. Atmospheric pollution, formation of H2S gas. Visual pollution Major effects on tourism, ethics and recreation Water pollution

Thus solid waste management involves management of activities associated with - generation, storage, collection, transfer and transport, reuse and recycling, processing and disposal which should be environmentally compatible, economically low-cost, aesthetically good and energy efficient.

Municipal solid waste Water treatment waste Special waste

Characteristics of Municipal Solid Waste Physical characteristics – It involves, (i) identification of individual component that make up MSW (ii) analysis of particle size (iii) moisture content (iv) density of solid waste. II. Chemical characteristics – It involves, (i) proximate Analysis (ii) Fusing point of Ash (iii) Ultimate Analysis of Solid waste components & (iv) Energy content of solid waste. The proximate analysis include tests such as, moisture content, volatile combustible matter, fixed carbon & ash determination. III. Biological characteristics – It include determination of Biodegradability of Organic Waste Components, Production of Odors, & Breeding of flies.

Physical Characteristics 1. Composition:

Typical Composition of MSW Component Range (% by mass) Typical (% by mass) Food waste 6-26 14 Paper 15-45 34 Cardboard 3-15 7 Plastic 2-8 5 Textile 0-4 2 Rubber 0-2 0.5 Leather Garden trimming 0-20 12 Wood 1-4 Glass 4-16 8 Tin cans 6 Non ferrous metals 0-1 1 Ferrous metal Dirt, ashes, bricks 0-10 4

Physical Characteristics 2. Particle Size: Important for recovery of materials. For mechanical separation such as using trommel screen & magnetic separators.

Magnetic Separator

Physical Characteristics 3. Moisture Content: Expressed as mass of moisture per unit mass of wet or dry material. Wet mass method: the moisture in a sample is expressed as a % of wet mass of the material. Dry mass method: the moisture in sample is expressed as a % of dry mass of the material. Where, a= initial mass of sample as delivered b = mass of sample after drying

Typical data on moisture content of MSW Component % Range % Typical Food waste 50-80 70 Paper 4-10 6 Cardboard 4-8 5 Plastics 1-4 2 Textiles 6-15 10 Rubber Garden trimming 30-80 60 Wood 15-40 20 Tin cans 2-4 3 Leather 8-12 Glass Non ferrous metals Dirt, ashes, bricks 6-12 8

Example Estimate the moisture content of a solid waste sample: Component % by mass Food waste 15 Paper 45 Card board 10 Plastic Garden trimming Wood 5 Tin cans

Physical Characteristics 4. Density: The density of MSW varies greatly with geographic locations, season of the year & length of time of storage. Great care should be taken when typical values are taken in to consideration.

Typical Densities for Solid waste Components & mixtures Density range ( kg/m3) Typical value (kg/m3) Food waste 120-480 290 Paper 30-130 85 Leather 90-260 160 Glass 160-480 195 Ferrous metals 120-1200 320 Un compacted MSW 90-180 130 Compacted in compactor truck 180-450 300 Normally Compacted in landfill 350-550 475 Well compacted in landfill 600-750 600

Example Estimate the as discarded density of solid waste sample for following composition. Component % by mass Food waste 15 Paper 45 Card board 10 Plastic Garden trimming Wood 5 Tin cans