We are living in a false economy wherethe price of goods and services does notinclude the cost of waste and pollution.–Lynn Landes, founder and director of Zero Waste America
Solid Wastes includeGarbage (food wastes)Rubbish( paper, plastics, wood, metal, throw awaycontainers, glass). Demolition products (bricks, masonry, pipes). Sewage treatment residue (sludge and solids from thecoarse screening of domestic sewage). Dead animals, manure, other discarded materials.
Solid waste if accumulated anywhere is a health hazard because :• It decomposes and favours fly breeding.• It attracts rodents and vermin.• Possibility of water and soil pollution.• Unsightly appearance and bad odours.Solid waste accumulation increases chances of vector bornediseases.
Sources of solid wastes :• Street refuse : collected by street cleaning service or scavenging e.g. : leaves, straw, paper, animal droppings.• Market refuse: contains putrid vegetables and animal matter.• Industrial refuse: contains wastes ranging from completely inertmaterials to highly toxic and explosive compounds.•Domestic refuse: contains ash, rubbish and garbage.
Waste• We all produce unwanted by products and residues in nearly everything we do.• According to the Environmental Protection Agency (EPA), the United States produces 11 billion tons of solid waste each year.• Industrial waste—other than mining and mineral production—amounts to some 400 million metric tons per year in the United States.• Municipal waste—a combination of household and commercial refuse—amounts to about 250 million metric tons per year in the United States.
Collection of solid wastes:Method depends on the funds available. Method of disposal: Dumping Controlled Tipping or sanitary land fill Incineration Composting Manure Pits Burial
Dumping : Easy method of disposal of dry solid waste. Land reclamation is often done by this method. Refuse decreases considerably in volume due to bacterial action and is gradually converted to humus.Drawbacks of open dumping are: - - - • Refuse is exposed to flies and rodents. • Source of foul smell and unsightly appearance. • Loose refuse is dispersed by the action of wind. • Drainage from dumps contributes to pollution of surface and ground water.
A WHO Expert Committee (1967) condemneddumping as “ a most unsanitary method that createspublic health hazards, a nuisance, and severepollution of the environment. Dumping should beoutlawed and replaced by sound procedures”.
Controlled Tipping: Most satisfactory method where suitable land is available.Solid waste is placed in a trench, compacted and covered with earth at theend of the working day. Controlled tipping is of three types: • Trench method: Long trench 2 – 3 m deep and 4 – 12 m wide is dug. Refuse is compacted and covered with excavated earth. • Ramp method: Suited when terrain is moderately sloping. • Area method: Used for filling land depressions, disused quarries and clay pits.
Why controlled tipping is a good method? • Chemical, bacteriological and physical changes occur in buried refuse. • Temp. rises to over 60 degrees within 7 days and kills all the pathogens and helps in decomposition. • Cools down in 2 – 3 weeks and within 4 - months complete decomposition of organic matter takes place.
Incineration(Burning) :Refuse can be disposed off hygienically by burningor incineration, however, hospital refuse which isdangerous is best disposed off by incineration.•Practiced in several of the industrialized countries.
Composting: Method of combined disposal of refuse and night soil or sludge.•It is a process of nature where organic matterbreaks down under bacterial action resulting information of relatively stable humus like materialcalled the Compost which has considerable value asa manure.
Composting recycles organic waste
Burial:This method is suitable for small camps.A trench 1.5 m wide and 2 m deep is excavated and at theend of each day the refuse is covered with 20 – 30 cms. ofearth.
Incineration(burn) produces energy but causes pollution• Waste incinerators burn municipal waste.• This technology is also called energy recovery, or waste-to-energy, because the heat derived from incinerated refuse is a useful resource.
Shrinking the Waste Stream• Having less waste to discard is obviously better than struggling with disposal methods, all of which have disadvantages and drawbacks.• The term recycling has two meanings in common usage. – Sometimes we say we are recycling when we really are reusing something, such as refillable beverage containers. – Recycling is the reprocessing of discarded materials into new, useful products.
Recycling captures resources from garbage
Public Health importance:A municipal waste if contaminated with excreta is a source of infection.The health hazards of improper waste disposal are:1. Soil Pollution.2. Water Pollution.3. Contamination of foods.4. Propagation of flies.
Diseases resulting from contamination are : 1. Typhoid and paratyphoid fever. 2. Diarrhoeas and Dysenteries. 3. Cholera. 4. Hook worm and other intestinal parasitic diseases. 5. Viral hepatitis. 6. Etc …
Occupational hazards associated with waste handlingInfections : -1) Skin and blood infections resulting from direct contact with waste, and from infected wounds.2) Eye and respiratory infections resulting from exposure to infected dust, especially during landfill operations.3) Different diseases that results from the bites of animals feeding on the waste.4) Intestinal infections that are transmitted by flies feeding on the waste.
Natural Capital Degradation: Solid Wastes Polluting a River in Indonesia
Hundreds of Millions of Discarded Tires in a Dump in Colorado, U.S.