Water Reuse and Zero Liquid Discharge

Definition of Recycled Water by the WateReuse Association:

“Recycled Water is the water that is used more than one time before it passes back into the natural water cycle. Wastewater that has been treated to a level that allows for its reuse for a beneficial purpose. Recycled water is sometimes another name for reclaimed water. “

Usually a tertiary treatment is added after the biological treatment using membrane technologies such like Ultra Filtration and Reverse Osmosis to further purify the waste water. This purified waste water would go through a disinfection stage to inhibit the microbiological contaminants.

Source: Degremont Technologies

 

Zero Liquid Discharge

In some specific circumstances for example extremely toxic waste water such like pesticide production plant or very stringent regulations, a Zero Liquid Discharge treatment unit will separate the dissolved solids via membrane filtration, return the clean permeate to the process and concentrate the brine for crystallization. After the this thermal process which separate the liquid from the solid content by evaporation, the final solid content will be eventually removed from the water source.

Source: Degremont Technologies