Hydrophobic Capillary Ceramic-Membrane Contactor for Recovering Ammonia from Sludge Hydrolysate

Area of Science:

• Environmental Engineering
• Chemical Engineering
• Materials Science

Background:

• Ammonia recovery from sludge hydrolysate (SH) is challenging due to high organic loads and variable conditions.
• Existing methods struggle with efficiency and purity under harsh operational parameters.

Purpose of the Study:

• To develop and evaluate superhydrophobic capillary ceramic-membrane contactors (MCs) for efficient ammonia recovery from SH.
• To assess the performance, stability, and anti-fouling properties of these MCs in both simulated and real SH systems.

Main Methods:

• Fabrication of superhydrophobic capillary ceramic-membrane contactors.
• Investigation of ammonia mass transfer under varying pH, flow rate, and ammonia concentration in a simulation system.
• Long-term continuous operation testing on actual sludge hydrolysate.
• Evaluation of membrane anti-fouling, wetting stability (contact angle), and product purity.

Main Results:

• Ammonia removal reached 93.6% in simulation and 90.3% in the actual SH system after 10 hours.
• Sustained ammonia recovery of 90.3% during long-term operation.
• Complete retention of organic matter in SH and high purity of recovered ammonium sulfate.
• Stable superhydrophobicity maintained with contact angles above 129.6° throughout operation.

Conclusions:

• Superhydrophobic capillary ceramic-membrane contactors offer a robust solution for efficient ammonia recovery from sludge hydrolysate.
• The developed MCs demonstrate excellent performance, stability, and anti-fouling capabilities for practical applications.
• This technology provides a viable method for recovering valuable ammonia resources while preventing organic contamination.