ZERO LIQUID DISCHARGE SYSTEM
Zero-liquid discharge (ZLD) is a water treatment process in which all wastewater is purified and recycled; therefore, leaving zero discharge at the end of the treatment cycle. ZLD is an advanced wastewater treatment method that includes ultrafiltration, reverse osmosis, evaporation/crystallization, and fractional electrodeionization.
Zero Liquid Discharge (ZLD) is a treatment process designed to remove all the liquid waste from a system. The focus of ZLD is to reduce wastewater economically and produce clean water that is suitable for reuse (e.g. irrigation), thereby saving money and being beneficial to the environment. ZLD systems employ advanced wastewater/desalination treatment technologies to purify and recycle virtually all of the wastewater produced.
Also ZLD technologies help plants meet discharge and water reuse requirements, enabling businesses to:
Meet stringent government discharge regulations
Reach higher water recovery (%)
Treat and recover valuable materials from the wastewater streams, such as potassium sulfate, caustic soda, sodium sulfate, lithium and gypsum
The conventional way to reach ZLD is with thermal technologies such as evaporators (multi stage flash (MSF), multi effect distillation (MED) and mechanical vapor compression (MCV)) and crystallizers and recover their condensate. Thus, ZLD plants produce solid waste.