What is a waste?

Rubbish from a building.
Dirty water from mining, industrial, and domestic use.
The amount of excavated material exceeding fill.
(mining engineering)
The barren rock in a mine.
The refuse from ore dressing and smelting plants.
The fine coal made in mining and preparing coal for market.

treat the waste

The world's richest nations are dumping hazardous electronic waste on poor African countries, says the head of the UN's Environment Programme .