Zero Liquid Discharge (ZLD) is a classification of water treatment processes intended to reduce wastewater efficiently and produce clean water that is suitable for reuse (e.g., irrigation). ZLD systems employ wastewater treatment technologies and desalination to purify and recycle virtually all wastewater received.
ZLD technologies help industrial facilities meet discharge and water reuse requirements, enabling them to meet government discharge regulations, reach higher water recovery (%), and treat and recover valuable materials from the wastewater streams such as potassium sulfate, caustic soda, sodium sulfate, lithium, and gypsum.
Thermal technologies are the conventional means to achieve ZLD, such as evaporators (for instance multi stage flash distillation), multi effect distillation, mechanical vapor compression, crystallization, and condensate recovery. ZLD plants produce solid waste.