Zero Liquid Discharge

Increasing legislation and industry demands, that no liquid effluents are either to be discharged or stored. In the case of inorganic effluents, the final product is usually a mixed salt and of no commercial value. In the case of organic effluents, the concentrate could be a liquid or ‘sludge’ and be viscous in nature. The key objective however is to select the optimal process, balancing capital expenditure with minimization of operating costs.

Zero liquid discharge is a water treatment process that is beneficial to industrial and municipal organizations and most importantly to the environment as it ends with no effluent or any discharge. It employs the most advanced waste water treatment technologies to purify and recycle virtually all of the waste water produced. Also Zero liquid discharge technologies help plants meet discharge and water reuse requirements, enabling businesses to:

• Meet stringent cooling tower blow down and flue gas desulfurization (FGD) discharge regulations.
• Treat and recover valuable products from waste streams.
• Better manage produced water.

A Zero liquid discharge facility (ZLD) is an industrial plant without discharge of wastewaters. Target ZLD is normally reached by

• Waste water strong recovery
• Pre-treatment and evaporation of the industrial effluent until the dissolved solids precipitate as crystals. These crystals can be used in fertilizer industry or can be used for land filling. The water vapors from evaporation is condensed and returned to the process