Waste properties and their modification by pretreatment

Industrial waste can be classified according to its material state, chemical nature or hazardous nature. Classification according to material state aims to identify the physical state of the waste, which is essential for sizing waste handling systems and selecting waste treatment equipment.

Industrial waste generally takes the form of complex, heterogeneous mixtures in various physical states (solid, liquid, gaseous). Generally speaking, a pelletizable waste is considered a solid, while a pumpable waste (liquid, suspension, sludge, paste, etc.) is considered a liquid. Distinguishing between states is sometimes difficult, as these characteristics can change with time and temperature (softening, melting, vaporization, etc.).