Zero Liquid discharge (ZLD) means that after reusing industrial water, the concentrated salts and pollutants in this portion of high-concentration wastewater are then discharged from the factory as solid waste through processes such as concentrated crystallization or pressure filtration, which can be sent to waste treatment plants for landfilling or recycling as useful chemical raw materials. This ensures that no liquid waste is discharged from the factory.
The ZLD is a comprehensive application of membrane separation, evaporation, crystallization, drying, and other physical and chemical processes. This technology effectively removes solid impurities from highly concentrated wastewater while recycling most of the water.
Currently, the ZLD approach is widely used in industries such as mine water treatment, power plant wastewater treatment, smelting wastewater treatment, RO concentrated water treatment, reclaimed water reuse, and others. This approach has successfully generated significant environmental benefits.
Multi-Effect Evaporation (MEE) and Mechanical Vapor Recompression (MVR) technologies, used globally for 30 years, are proven, energy-efficient evaporation technologies. Overall, these advanced technologies can reduce the cost of conventional evaporators by up to 50%-70%. Evaporation and crystallization processes are widely used in today's industrial market.
Hydromaster in partnership with Sunevap, offers customized solutions with highly integrated process solutions to meet the specific needs of each client. With over 1000 installations with evaporation and crystallization systems playing a critical role in various industrial processes that:
- Produce pure products from natural deposits
- Recover by-products from waste streams
- Volume reduction and water recovery for environmental benefits
Evaporation crystallization system plays a crucial role in achieving ZLD of wastewater, exerting significant influence on the feasibility of realizing such zero liquid discharge.
Specifically, MVR technology employs a compressor to compress the secondary steam, thereby increasing its pressure and saturation temperature. This compressed steam is then utilized as heat source, replacing the need for fresh steam. Additionally, this process eliminates the requirement for cooling treatment, resulting in relatively lower operational costs.