Leachate

Landfill leachate

Use in mining

Heap leaching

In situ leach

Other types

Main article: Leaching (chemistry)

Leachate can also be produced from land that was contaminated by chemicals or toxic materials used in industrial activities such as factories, mines or storage sites.

Composting sites in areas and/or times of high rainfall also produce leachate. Due to the makeup of compost, which often consists of materials that degrade relatively easily compared to the makeup other waste collection sites, prolonged moisture exposure and occurrence of anaerobic digestion, which can occur due to the collapse of compost piles. The critical portion then involves exposure to precipitation, which causes the decomposed matter to flow, becoming runoff and therefore leachate.

Leachate is associated with stockpiled coal and with waste materials from metal ore mining and other rock extraction processes, especially those in which sulfide containing materials are exposed to air producing sulfuric acid, often with elevated metal concentrations.

In the context of civil engineering (more specifically reinforced concrete design), leachate refers to the effluent of pavement wash-off (that may include melting snow and ice with salt) that permeates through the cement paste onto the surface of the steel reinforcement, thereby catalyzing its oxidation and degradation. Leachates can be genotoxic in nature.

A possible risk for the aquatic environment due to the occurrence of organic micropollutants in raw or treated landfill leachates has also been reported in recent studies.

References

References

1. "Composting in the Southeast".
2. (Feb 2007). "Mutagenicity of leachates from industrial solid wastes using Salmonella reverse mutation assay". Ecotoxicol Environ Saf.
3. (2024). "Selected organic micropollutants in the aquatic environment". Desalination and Water Treatment.