ABSTRACT
A method that not only helps reduce water usage, but also concentrates on eliminating water discharge is known as Zero Liquid Discharge (ZLD). ZLD processes purify and recycle plant wastewater, changing liquid waste into disposable dry solids and delivering effluent water back into the plant process stream to be reused. ZLD processes can incorporate many different unit operations to eliminate water discharge including cold lime softening, evaporation and crystallisation and evaporation ponds. These technologies can deliver valuable financial returns where water conservation and strict permitting regulations have significantly increased the cost of industrial use.
