ZERO LIQUID DISCHARGE
BRINE TREATMENT AND ZERO LIQUID DISCHARGE (ZLD)
Galvanizing industries, electroplating industries, semiconductor industries, metal processing industries, chemical industries, pharmaceutical industries, oil & gas industries and many other industries generate high saline wastewater. The recycling rate in these industries are < 20%. Conventional treatment processes (chemical and biological) does not remove salinity. Reverse osmosis is the well-known technology to treat saline wastewater however; it is limited with salt concentration in the feed water due to osmotic strength. Moreover, it is always a challenge to treat/dispose the RO rejection/brine/high strength wastewater. Disposing the rejection back to the sea / sewer is another environmental issue that needs to be addressed. Conventional distillation and evaporation methods are too expensive. Inexpensive, environmental friendly technologies are critical for brine treatment and zero liquid discharge (ZLD).
Memsift Innovations Pte Ltd has an innovative thermal membrane process based ZLD system that can be used to treat the above industrial wastewater at almost 5 times less energy compared to current incineration method. The novel ZLD system consist of a unique highly hydrophobic hollow fiber membrane, which enhance the efficiency of the system. The technology has been proved for brine treatment to reach ZLD and recover the valuable resources from the industrial wastewater.
Technology Features & customer benefits
The novel membrane based ZLD system has several advantages over conventional distillation and evaporation systems. The key advantages of the system are as follow:
- Up to 100% water recovery
- Up to 50% Energy saving
- Up to 50% capital cost & space saving
- Independent of salt concentration
- Less or no pre-treatment required
- Low operating temperature (60-80°C)
- Corrosion free plastic materials
- Modular system (Easy scalability)
- High thermal efficiency (The system can be operated at higher Gain Output Ratio (GOR) due to efficient heat recovery)
Brine treatment to achieve zero liquid discharge: The technology has been proved for brine treatment. Based on the preliminary data, the membrane based ZLD system consumes very low energy compared to the conventional thermal methods. As the system is made up of 100% plastic materials, the capital cost may reduce to >50%. Hence, the new membrane based ZLD system will have tremendous opportunities in the market place for brine treatment to achieve zero liquid discharge.
Used acid recovery: Galvanizing, electroplating and semiconductor industries are using excess of inorganic acid and the wastewater containing these inorganic acids are categorized as hazardous waste and there are regulations to transport and incinerate these wastes. If we use this novel membrane based system, it can recover the acid from the waste, which can be potentially used for the process again; this will help the industry to be more sustainable.
Pervaporation to separate organic solvent and bio-fuels: As the driving force for this membrane system is vapor pressure difference, a liquid mixture with two different boiling point can be separated. Example; water-ethanol, water-isopropyl alcohol, water-acetone, ethylene glycol-water etc.,