In many industrial sectors—such as chemical manufacturing, textiles, oil & gas, and desalination—high-salinity wastewater has become an unavoidable challenge.
What makes it difficult is not only the salt itself, but the way salinity disrupts biological treatment, accelerates corrosion, and drives up operating costs.
What is High-Salinity Wastewater?
High-salinity wastewater refers to wastewater containing a high concentration of dissolved inorganic salts—such as chlorides, sulfates, sodium, calcium, and magnesium salts.
High-salinity wastewater treatment is the application of physical, chemical, biological, and membrane-based technologies to remove pollutants, reduce salinity, enable water reuse, or achieve zero liquid discharge (ZLD).
Characteristics of High-Salinity Wastewater
High Salinity Exerts Strong Inhibitory Effects On Biochemical Systems.
High salinity strongly inhibits microbial activity, making conventional biological treatment inefficient and unstable.
Water Quality Composition Is Complex
The composition varies widely by industry, so treatment processes must be customized for each wastewater type.
Equipment Is Prone To Corrosion And Has A High Risk Of Scaling
High levels of chlorides and sulfates cause severe corrosion and scaling, increasing demands on equipment and maintenance.
Brine Requires Secondary Treatment
Even after desalination by membranes, concentrated brine remains and requires further treatment or resource recovery.
High-Salinity Wastewater Treatment Technologies
Physical & Chemical Pretreatment
- Technology: Grating, sedimentation, coagulation-air flotation, sand filtration, activated carbon.
- Function: Removes suspended solids, oils, and heavy metals to protect downstream systems.
Salt-Tolerant Biological Treatment
- Technology: Halotolerant bacteria domestication, SBR, MBR, A/O process.
- Application: Moderately saline wastewater with high organic pollutant content.
Membrane Separation Technologies
- Technology: UF / NF / RO / DTRO.
- Function: Desalination, concentration, reclaimed water production.
- Characteristics: Highly efficient but prone to membrane fouling and concentrate water issues.
Evaporation & Crystallization
- Technology: MVR, Multi-Effect Evaporation, Forced Circulation Evaporator.
- Applications: High-salinity wastewater, Zero Liquid Discharge (ZLD) projects.
Salt Recovery & Resource Utilization
- Technology: Salt separation crystallization, freeze crystallization, mother liquor recovery.
- Objective: Transform “waste salt” into “resource”.
Integrated Treatment
In most industrial applications, the optimal solution is an integrated treatment system, combining several technologies:
Segregation → Physico-chemical pretreatment → Biological treatment (aerobic or anaerobic) → Membrane desalination → Concentrate management
System selection must be based on:
- Salinity level
- COD and biodegradability
- Flow rate and variability
- Discharge or reuse requirements
- Long-term operating cost
Conclusion
High-salinity wastewater is not solved by one technology, but by the right strategy—
reducing salt at the source, treating by salinity level, and integrating biological, membrane, and thermal processes into a stable system.
At GL Environment, we specialize in customized wastewater treatment solutions tailored to high-salinity and complex industrial effluents. Contact us to discuss your project requirements and explore a solution designed specifically for your process and discharge goals.