Conventional wastewater treatment processes are often ineffective at removing micropollutants, which pose risks to aquatic ecosystems and human health. To address this, a novel method was developed to immobilise activated carbon (AC) onto three-dimensional alumina spheres, enabling easier operation and regeneration while enhancing sustainability and efficiency in treating organic micropollutants.

The immobilisation process involved thermal decomposition of commercial AC (AC_com) with urea in water. Pristine AC_com and urea were also treated similarly for comparison. The adsorption performance was evaluated in batch and continuous flow systems using venlafaxine (VFX) as a model contaminant. Regeneration was studied via catalytic wet peroxide oxidation (CWPO), using hydrogen peroxide (H₂O₂) to restore adsorbent functionality.

Batch experiments showed that AC_com removed >99% of VFX, while AC/U₅₀ achieved 67.1% removal in 60 minutes. Immobilisation onto alumina spheres was only successful via thermal treatment with urea, forming S-AC/U₅₀. In a continuous flow, S-AC/U₅₀ removed 70% of the VFX in 60 minutes, with saturation after five days.

Introducing H₂O₂ activated CWPO, boosting the VFX removal to 99% and maintaining >97% efficiency over five days, preventing adsorbent saturation. The H₂O₂ consumption ranged from 9% to 45%, confirming catalytic activity and regeneration potential.

In summary, AC was successfully immobilised onto alumina spheres via thermal treatment with urea. The resulting S-AC/U₅₀ material demonstrated a high adsorption and regeneration performance, especially under CWPO conditions, offering a promising strategy for sustainable micropollutant removal in water treatment systems.