Reverse osmosis system - wastewater treatment
Reverse osmosis system - wastewater treatment

In wastewater treatment, what does MLD (minimal liquid discharge) and ZLD (zero liquid discharge) mean?

These terms are related to the amount of purified water that can be extracted in a wastewater treatment process.

Standard wastewater reclamation processes remove up to 70% of the water from the waste stream. MLD processes such as reverse osmosis or nanofiltration remove between 70-95% of the water. ZLD wastewater treatment processes recover 95-100% of water, usually with evaporator or crystallizer technologies.

The cost to achieve ZLD can be twice as much as MLD, so choosing the best water recovery system depends on cost-benefit analysis, environmental considerations, and other specific needs.

How much water are you currently reclaiming in your wastewater treatment process?