Wastewater treatment involves the collection and storage of used water, and the removal of contaminants contained in it so that it can be converted into an effluent and recycled back into the water grid or environment. The following industry sectors specialise in these water and sludge treatment processes:
- Municipal water treatment
- Sewage/sludge treatment
- Mining, food, and beverage
- Pulp and paper
- Animal processing
- Landfill leachate
Large digester tanks situated on water treatment plants contain bacteria that breaks the sludge down to release methane gas, which is then collected as biogas and used to generate electricity or produce bio slurry fertiliser for farmland.