SOLID+WASTE!



SOLID WASTE!

Main Types

Mining Waste -Produced by mining operations, either material removed to obtain a valuable material or what ore is removed from. -Estimated 1 to 2 billion metric tons produced each year -700 to 800 million tons are considered hazardous

Agricultural Waste -The waste resulting from the processing of animals or plants. -1.5 billion metric ton produced per year -90% is recycled as fertilizer

Industrial Solid Waste -By products from manufacturing -Estimatred 200 to 600 million metric tons produced per year

Municipal Solid Waste -common household waste -210 million metric tons per year

Disposal of Solid WASTE:

Disposal of solid waste is often a difficult task in large urban areas, especially cities. Cities generate immense amounts of garbage and must find a location to store it, usually far away. New York City, for example, used to dispose of all it's waste on Staten Island but as of 2001 that site has been closed and NYC is now exporting most of its solid waste to other parts of New York and bordering states.

Interesting fact; archeologists use garbage from ancient human civilizations to learn more about how those societies functioned. (It was in the book so I figured I'd include it)

History: It has been common practice in the past to simply dump waste in local bodies of water or burn any waste. But as civilization has moved forward an emphasis has been placed on the environment and the science of solid waste disposal has moved forward. There are now 5 ways to dispose of solid waste. (1) Landfills, (2) Incineration, (3) Source Reduction, (4) Composting and (5) Recycling.

Landfills:

As it turns out landfills are more than just holes in the ground. They have become huge areas specially prepared at $400,000 per acre to house and decompose our trash while containing it. Below is a diagram of a modern landfill:

There are several systems buit into the landfill to contain all waste and byproducts. First there is a clay liner surrounding the entire thing (clay is not very permeable to water). Rain may seep through the waste, once it has done this and been contaminated it is called leachate. A pipe system will pump the water out of the bottom of the landfill for treatment. There is another pipe system that is used to capture Methane Gas. There also exist serval other monitoring wells to continually test for leaks.

Landfills used to be our primary waste disposal method and because of that there were 8000 active and licensed dumps in the US in 1988. This has decreased to 1650 dumps in 2005. This not because the amounts of waste disposed has changed (the actual amount has stayed roughly the same) it is because small and common landfills have filled up or have violated regulation. Todays landfill is huge. Landfills are extremely hard to place because so many factors limit where they can be. There are watersheds, wildlife, geological features and especially NIMBY. (Not In My Back Yard) Political voices are the strongest, so when the government finds a place where not many people complain (probably a poor and uneducated area) they will jump on it. Landfills are being phased out for this reason and the fact that recycling and incineration are much most cost effective.

Incineration:

The process of burning waste. The US burns about 15% of its solid waste (compared to Canada's 8%). Most of the time the burning trash is used to produce power. As of 2005 there were 125 incinerators with a capacity to burn 96,000 metric tons of Municipal Solid Waste per day. The waste is usually processed into pellets and then burned. Incinteration reduces the volume by 90% and weight by 75%. Incineration is very controlled and produces relatively few emmissions, however the polutants it does release are released into the air and are dangerous and cancer-causing.

Incinerators are quite costly, currently costing more than landfills and rising. Each year new technology is created and added to the disign of the plant and causes the cost to rise. The EPA also favors other methods like source reduction and recycling.

Source Reduction:

Composting:

Many things we throw away can actually be used



Recycling:



(There is a [not so] subtle hint in this photo)