Rising Sulfuric Acid Costs Are Changing How Industries Handle Waste Salt
As industries face rising sulfuric acid prices, stricter wastewater discharge regulations, and growing pressure to improve resource efficiency, more manufacturers are turning to Bipolar Membrane Electrodialysis (BPED) technology for industrial brine treatment and chemical recovery.
A BPED system for sodium sulfate recovery and industrial waste salt recycling has recently been successfully commissioned in Ningxia, China, demonstrating a practical approach to converting high-salinity wastewater into valuable reusable resources.
The project is designed to treat sodium sulfate-rich nanofiltration concentrate generated from industrial wastewater processes. Instead of treating the stream as waste, the system enables resource recovery and supports zero liquid discharge (ZLD) and circular manufacturing strategies.
Project Overview
• Technology: Bipolar Membrane Electrodialysis (BPED)
• Application: Sodium sulfate recovery & industrial brine recycling
• Feed Stream: Sodium sulfate-rich brine containing trace NaCl
• Current Feed TDS: ~100 g/L
• Original Design Feed TDS: 190–210 g/L
The original process design utilized dissolved sodium sulfate solids recovered from nanofiltration concentrate. Following pretreatment processes including ozone oxidation, resin purification, ultrafiltration, and decarbonization, the feed solution entered the BPED system for further conversion and resource utilization.
One of the key challenges of this project was fluctuating onsite feedwater quality. Despite significant variations between actual operating conditions and the original design parameters, the BPED system maintained stable, continuous operation throughout commissioning.
This project highlights several important advantages of membrane-based acid and alkali recovery technologies:
✔ Stable operation under complex and variable brine conditions
✔ Reduced dependence on externally purchased sulfuric acid and caustic soda
✔ Lower hazardous waste treatment and disposal costs
✔ Efficient treatment of high-salinity industrial wastewater
✔ Support for zero liquid discharge (ZLD) systems
✔ Flexible integration with existing wastewater treatment infrastructure
✔ Improved industrial resource recovery and circular utilization
With increasing global demand for sulfate waste recovery, sustainable chemical recovery, and industrial wastewater reuse, BPED technology is becoming an increasingly important solution for industries including chemicals, mining, lithium battery materials, metallurgy, and environmental engineering.
Backed by in-house ion exchange membrane manufacturing, electrodialysis stack production, and integrated BPED system engineering capabilities, LANRAN provides customized solutions for complex industrial separation and resource recovery applications worldwide.
