Humic Acid Recovery from Leachate Nanofiltration Concentrate Using Halloysite Nanotube-Coated Tubular Ceramic...

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Landfill wastewater contains valuable humic acids (HAs), posing environmental challenges.
• Nanofiltration (NF) concentrate from treatment requires innovative solutions for HA recovery.
• Circular economy principles necessitate pollution-resistant separation technologies.

Purpose of the Study:

• To develop and evaluate a hybrid membrane system for humic acid (HA) recovery.
• To integrate halloysite nanotubes (HNTs) as a dynamic coating on ceramic ultrafiltration membranes.
• To assess the adsorption-desorption performance of HNTs for HA recovery.

Main Methods:

• Batch adsorption-desorption experiments were conducted using HNTs.
• Tube-shaped ceramic ultrafiltration membranes were coated with HNTs.
• Membrane performance was tested with synthetic and real NF concentrate.

Main Results:

• HNT adsorption of HAs followed the Freundlich isotherm model.
• Maximum HA adsorption capacity increased with initial concentration.
• Desorption studies achieved up to 74.6% HA recovery using NaOH.
• Membrane filtration showed 85.3% HA removal in synthetic solutions.
• Real NF concentrate yielded lower removal (19-64%) and recovery (up to 59.3%) due to matrix complexity.

Conclusions:

• HNT-coated membranes offer a potential method for HA recovery from landfill wastewater.
• The hybrid system demonstrates feasibility for circular economy applications.
• Wastewater matrix complexity impacts separation efficiency, requiring further optimization.