Diffusion Dialysis (DD) Test Equipment — Accurate, Efficient & Ready for Real Chemistry

Diffusion Dialysis (DD) is one of the most energy-efficient membrane technologies available today for acid recovery and industrial wastewater treatment. YASA ET’s DD Laboratory Test System, built with our YTDD-series ion-exchange membranes, provides a compact, reliable, and highly repeatable platform for testing acid–water separation performance in real industrial conditions.

Designed for researchers, universities, chemical manufacturers, and membrane technology developers, the DD test unit helps evaluate acid recovery efficiency, ion permeability, and membrane stability under different operating conditions.

1. What the DD Test Equipment Is Designed For

The YASA ET DD test device is engineered for:

• Acid recovery (H₂SO₄, HCl, HNO₃, HF mixtures)

  
  

• Metal finishing wastewater (Ni, Cr, Zn, Cu)

  
  

• Lithium battery recycling solutions

  
  

• Chemical process optimization

  
  

• New membrane development and QC testing.

  
  

  Using diffusion dialysis, acid molecules diffuse through the anion exchange membrane (AEM), while metals and impurities remain in the retentate stream, enabling efficient acid reuse and reduced chemical consumption.

2. How the Test Is Set Up

A typical DD test involves two circulating solutions:

• Acid Solution (Feed):  

  
  

  - 15% H₂SO₄ in the example test  

  - Flow rate: 10 mL/min 

  - Objective: Recover free acid while retaining metal ions

  
  

• Water Solution (Dialysate):  

  
  

  - Pure water  

  - Flow rate: 12 mL/min  

  - Objective: Capture acid diffusing across the membrane

  
  

• The DD stack used is the YTDD 8-40, with a 20 × 40 cm membrane area. The system includes:

  
  

  - Two chemical-resistant circulation pumps- Two flow meters

  - Two solution tanks- DD membrane stack module- Sampling ports

  - Optional IoT sensors for online pH, conductivity, and temperature

  
  

• Simple Setup Steps:

  
  

  1. Prepare the solutions: Fill Tank A with acid solution and Tank B with pure water.

  2. Prime the pumps: Ensure both loops are filled and free of air.

  3. Set the flow rates: Adjust pumps to 10 mL/min (acid) and 12 mL/min (water).

  4. Start continuous circulation: Allow the system to reach steady state.

  5. Collect samples over time: Typical sampling interval: every 10–30 minutes.

  6. Analyze acid concentration: Using titration, conductivity, or density measurement.

3. How the Test Works

Diffusion dialysis depends on natural concentration gradients, not electricity.

Inside the membrane stack:

- H⁺ and SO₄²⁻ ions selectively migrate across the AEM.

- Large molecules and metal ions are rejected.

- Acid accumulates in the dialysate stream.

This passive separation mechanism makes DD extremely cost-effective compared with evaporation or neutralization.

4. Example of Test Results (15% H₂SO₄)

Key Observations:

- The acid concentration in the water stream steadily increases over time.

- The retentate stream gradually decreases in acidity, indicating successful diffusion.

- The system remains stable at both 10 and 12 mL/min flow rates.

- The YTDD 8-40 membrane shows strong permeability while maintaining high selectivity.

These results confirm that YASA ET DD membranes maintain a consistent diffusion rate and excellent chemical resistance.

5. Why YASA ET DD Test Equipment is a Preferred Choice

• High-Precision Testing

  Designed for academic research and industrial process verification.

  
  

• Chemical-Resistant Materials

  All wetted components withstand strong acids up to 30–40%.

  
  

• Easy Data Collection

  Multiple sampling ports and optional real-time data logging.

  
  

• Simple Operation

  No high-pressure pumps, no electricity for the separation process.

  
  

• Scalable & Customizable

  From small lab stacks to full industrial skids for 500–10,000 L/h.

6. Conclusion

YASA ET’s Diffusion Dialysis Test Equipment provides a practical, clean, and cost-effective way to evaluate acid recovery performance in real industrial environments. With precise flow control, durable AEM membranes, and easy data collection, users can quickly:

- Assess membrane quality

- Optimize process parameters

- Predict industrial-scale performance

Whether you are validating a new production strategy or conducting membrane research, the YTDD-series DD test platform delivers reliable, reproducible results.