Work

Urea-based immobilisation of activated carbon onto alumina spheres for adsorption of organic micropollutants and regeneration by catalytic wet peroxide oxidation

Year: 2025

Type: article

Abstract: Activated carbon (AC) was mixed with different doses of urea (U) and subjected to a single-step thermal treatment process. The AC-based materials were synthesised in powder form (AC/U x , x representing the U:AC weight ratio) and also immobilised onto alumina spheres (S-AC/U x ). The materials were characterised by different techniques, including diffuse reflectance ultraviolet-visible spectroscopy (DRUV-Vis), photoluminescence (PL) spectroscopy, N 2 adsorption-desorption isotherms, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). It was demonstrated, for the first time, that U allows for the proper one-pot solvent-free immobilisation of AC onto alumina supports. In batch adsorption experiments, the best-performing material in powder form (AC/U 50 ) showed a venlafaxine (VFX) removal of 67.1 ± 7.6 % in 60 min. In continuous flow mode adsorption experiments performed with VFX spiked in tap water (packed-bed configuration), the respective supported material (S-AC/U 50 ) reached a VFX removal of 70 %. Adding hydrogen peroxide (H 2 O 2 ) improved the removal of VFX up to 99 %, demonstrating the ability of the material to activate H 2 O 2 at room temperature. This catalytic wet peroxide oxidation (CWPO) process not only enhances the degradation of VFX but also reveals the potential for regenerating S-AC/U 50 , offering a promising route for sustainable and efficient drinking water treatment. • Best adsorbent (AC/U 50 ) prepared with 50 g of urea (U) / g of activated carbon (AC). • AC successfully immobilised onto alumina spheres (S) by urea-rich thermal method. • S-AC/U 50 removed up to 70 % of VFX from tap water, reaching saturation in 5 days. • S-AC/U 50 with H 2 O 2 improves VFX removal up to 99 % at room temperature. • CWPO allows for 5 days of continuous operation with no loss of catalytic activity.

Source: Chemical Engineering Journal

DOI: 10.1016/j.cej.2025.171031

Authors: Joana J.M. Dele, André Torres-Pinto, Ana M. Chávez, Adrián M.T. Silva

Institutions: Universidade do Porto, Universidad de Extremadura

Language: English

Topic: Advanced oxidation water treatment

Subfield: Water Science and Technology

Field: Environmental Science

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production, Good health and well-being

Open Access status: hybrid

Estimated APC paid: $4,830