Garbage (waste, trash) – unwanted and discarded materials and objects. It is often also called trash, garbage, rubbish, or junk. There are a number of different types of waste. It can exist as a solid, liquid, or gas or as waste heat. Garbage is the waste produced daily in our homes. It includes different waste like food, chemical substances, paper, broken furniture, used containers, and other things.

Solid waste – as there is lots of stuff that is considered to be waste, garbage or trash is usually specifically stuff left over or produced by people living in cities and towns. Garbage may be distinguished from other forms of waste by calling it Solid Waste.

• urban waste – packaging, discarded household goods, litter
• food waste – animal and vegetable matter that is not eaten – bones, skin, seeds, over-ripe, decaying
• construction, demolition, building materials – unusable extras, broken, rubble, needs to be cleared to make way for the next use of the land

Other forms of waste include output from people and animals, factories, processing and cultivation.

Waste management

• waste receptacle – a container for temporarily storing refuse and waste. There are many different designs and materials (small or large, with or without a lid; metal or plastic) and uses (public space, private home).
• transporting – collection, removal
• burying – landfill
• burning – incineration

What’s the problem?
Innovation in trash processing
Baltimore’s Solar Wheel pulls in 25 tons of harbor garbage daily – Baltimore’s newest green machine—a trash-collecting water wheel powered by the sun—is expected to extract some 50,000 pounds of garbage from coastal waters every day. Every day.

• Ask – Baltimore is on the coast, so in addition to regular trash pickup, the city also has to deal with garbage that washes onto the shore. This trash is floating so getting it out of the water is a problem too. How can the trash be removed from the water? How can the cost of this trash pick-up be kept down?
• Imagine – There is wave action and water movement, so the trash can be moved by water to a collection and processing area. How can the floating trash be picked out of the water? How can it be processed at the same location? Can solar energy be used for the processing?
• Plan, Create – The solution was to use solar energy to power a water wheel. The wheel has blades that remove the trash from the water.
• Improve – Many new and innovative solutions are being developed to process trash. Ones like this that use solar energy get the trash picked up effectively.