Zero Liquid Discharge (ZLD)
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. Zero liquid discharge is an advanced wastewater treatment method that includes ultrafiltration, reverse osmosis, evaporation/crystallization, and fractional electrodeionization.
Aquatech has an unparalleled depth of experience in zero liquid discharge (ZLD), which include more than 160 installations, including stand-alone thermal/evaporative processes, membrane processes, or hybrid systems.
Zero Liquid Discharge (ZLD) At a Glance
160 zero liquid discharge installations on 6 continents
Innovators in Hybrid zero liquid discharge, merging membranes, and thermal evaporators
Reliable and cost effective solutions
Customer support for long term reliability
Specialized zero liquid discharge operation and maintenance services
Technologies
Falling Film Brine Concentrators
Forced Circulation Crystallizer
Horizontal Spray Film Evaporator
Hybrid Systems with Membrane Pre-Concentrators
Biological Treatment
Solids Waste Handling
The power industry as well as oil & gas, chemical, petrochemicals, mining and other industries generate large volumes of waste water that must be managed. Commonly these wastewaters are discharged via a plant outfall to a surface water body, an evaporation pond, or in some cases deep well injected. However, there are growing environmental concerns regarding such discharge practices, which has resulted in the development of Zero Liquid Discharge (ZLD) processes.
Zero liquid discharge can be defined broadly as a process for maximum recovery of water from a waste water source that would otherwise be discharged. This water is beneficially reused and the salts, and other solids contained in the waste water are produced and generally disposed in a landfill.
Zero Liquid Discharge
The drivers for zero liquid discharge include a growing concern by the public about the impact of such discharges on the environment, and in many areas of the world, water is a scarce resource. Such concern is resulting in increased regulation and limitation of waste water discharges. Even without regulatory push, many companies in various industries are mandating initiatives for reducing water discharge by recycle reuse, as well as ZLD, to reduce their environmental footprint and improve sustainability.
Zero liquid discharge can be achieved in various ways. There is no “one size fits all” solution, as the optimal system design is site specific. The waste water composition, various streams to be treated, site specific operating costs, foot print availability and other factors are determining factors for an optimal design.
The system objectives for a zero liquid discharge system are to eliminate a liquid waste water discharge, generate solids for landfill disposal or reuse, and to recycle a high-quality water that can be beneficially reused. The design objectives are to minimize the capital investment and system operating cost, while not significantly impacting the manpower required for operation. Further, the system must be designed with operational flexibility to meet the facility needs and be safe and reliable.