Industrial Waste

Coal Ash

Coal ash is the byproduct of burning coal, including fly ash, bottom ash, boiler slag, and flue gas desulfurization material ¹. Coal ash contains harmful materials, such as arsenic, cadmium, and mercury, and it can cause water and air pollution ¹. Burning one ton of coal produces about 0.15 tons of ash ².

Following spills at Kingston, Tennessee, where at least 30 clean-up workers have died from illnesses suspected to be linked to the spill ³, and at Eden, North Carolina ⁴, the U. S. EPA has instituted regulations on coal ash disposal. The rules requires liners to control water pollution and other safeguards, but it may be inadequate ⁵.

Steel Slag

Slag is a byproduct of steelmaking. The United States generates 7-7.5 million tonnes of slag per year ⁶. Slag produced during the primary steelmaking phase is called furnace slag and is usually recycled into aggregates ⁶. Slag produced at later stages of the process does not have mechanical properties that are suitable for aggregates, and it is usually disposed of ⁶.

Other Industrial Waste

Other forms of industrial waste include organic solvents from laboratories, dyes and glazes from the ceramics and textiles industries, brake/transmission fluid, industrial wastewater, and others ⁷.