# High Performance of Al-MCM-41 in Tetracycline Adsorption Using a Fixed-Bed Column

## TL;DR

Al-MCM-41 effectively removes tetracycline from water in both batch and continuous systems, showing promise for sustainable water treatment.

## Contribution

Demonstrates the practical applicability of Al-MCM-41 in continuous-flow systems for removing tetracycline.

## Key findings

- Al-MCM-41 achieved a maximum adsorption capacity of 82.74 mg g–1 in batch experiments.
- Fixed-bed column experiments showed an adsorption capacity of 19.1 mg g–1 using the Yan model for breakthrough curves.
- The adsorption process was found to be spontaneous and exothermic, indicating combined physisorption and weak chemisorption.

## Abstract

This study investigates the adsorption efficacy of aluminum-modified
mesoporous silica (Al-MCM-41, Si/Al = 16.1) for the removal of tetracycline
(TC) from aqueous solutions, employing both batch and fixed-bed column
systems in the quest for sustainable solutions to eliminate emerging
contaminants. The synthesized material exhibited a highly ordered
hexagonal structure and high surface area (∼850 m2 g–1), confirmed by X-ray diffraction, nitrogen
physisorption, FTIR, and transmission electron microscopy analyses.
Batch adsorption kinetics followed a pseudo-second-order model, indicating
surface-controlled uptake, while isotherm data fit both Langmuir and
Freundlich models, with a maximum adsorption capacity of 82.74 mg
g–1. Thermodynamic analysis revealed a spontaneous
and exothermic process (ΔH° = −25.8
kJ mol–1), suggesting combined physisorption and
weak chemisorption. In fixed-bed column experiments, the Yan model
provided the best fit to breakthrough curves, achieving an adsorption
capacity of 19.1 mg g–1 at an influent concentration
of 15 mg L–1. These results demonstrate the good
efficiency and practical applicability of Al-MCM-41 in continuous-flow
systems for removing emerging contaminants such as TC, supporting
the development of sustainable water treatment technologies.