Nitrogen-containing wastewater flows outside hollow fiber membranes, with sulfuric acid introduced inside. Ammonia (NH₃) is absorbed by sulfuric acid through micropores, while water molecules are blocked, ensuring efficient deamination.
To ensure low dissolved oxygen levels in product water (typically <300 ppb), a combined method of vacuum extraction and inert gas purging is typically employed. A simplified process flow is illustrated in the image.
The membrane contactor consists of two sides: a liquid side for the oxygen-rich ultrapure water, and a gas side where high-purity nitrogen is introduced from one end while vacuum is applied at the other. The feedwater is usually deionized or desalinated water saturated with dissolved oxygen (6–10 ppm), at a temperature of 5–40°C. After passing through 2 to 4 stages of membrane contactors, the dissolved oxygen is reduced to the desired level. A pressure drop of 0.1–0.3 MPa occurs in the water stream.
High-purity nitrogen (purity ≥ 99.99%) is introduced from the top of the gas side. It sweeps through the membrane, collecting dissolved gases such as nitrogen, oxygen, and carbon dioxide from the water. These gases are then extracted through the bottom port using a vacuum pump. The vacuum level at the membrane module’s outlet is maintained at –0.092 to –0.096 MPa.
A water-ring vacuum pump is used, which requires a supply of cooling water. At the vacuum pump’s outlet, a gas-liquid separator is installed to remove water from the extracted gas stream. The exhaust—comprising clean, uncontaminated water and gas—is safely discharged into the ambient atmosphere.
At Edgecross, our core strength revolves around advanced membrane contactor systems that optimize gas and vapor management. Leveraging cutting-edge materials and engineering, we enable precise separation and purification processes, delivering sustainable and efficient solutions for industrial applications.
Edgecross leads the industry with proven expertise and innovative solutions, as demonstrated by our key achievements:
12 Years
Years of experience in membrane contactor technology.
>100 Sets
Deaerators deployed across various industries.
>30 Sets
Energy-saving systems installed for clients.
<2 Years
Return on investment achieved in under 2 years.
12%
Maximum boiler efficiency improvement achieved.
1000 t/h
Capacity of the largest deaerator in operation.
Φ400
Maximum diameter of our membrane contactors.
65°C
Maximum operating temperature for our systems.