# Cu or Fe‐Exchanged Natural Clinoptilolite as Sustainable Light‐Assisted Catalyst for Water Disinfection at Near Neutral pH

## TL;DR

This paper explores using iron or copper-exchanged natural clinoptilolite as low-cost, sustainable catalysts for water disinfection under visible light.

## Contribution

The study introduces copper-exchanged clinoptilolite as a reusable and effective photocatalyst for water disinfection under near-neutral pH.

## Key findings

- Both Fe- and Cu-exchanged clinoptilolite achieved bacterial detection limits in 2 hours under visible light.
- Cu-exchanged clinoptilolite showed better reusability across three disinfection cycles.
- Hydroxyl radical generation and disinfection kinetics were analyzed using multiple models.

## Abstract

Natural zeolites can be used to obtain effective catalysts for heterogeneous photocatalytic reactions due to their low cost and favorable physicochemical properties for water treatment. In this work, a natural clinoptilolite is modified by incorporating iron (NZ–Fe) and copper (NZ–Cu) as compensation cations through ion exchange processes. Metals incorporation and structural stability are demonstrated through X‐ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. DR‐UV–Vis measurements are used to estimate the bandgap and predict the photocatalytic performance of both materials. Their effectiviness in heterogeneous photocatalytic systems is confirmed by evaluating the inactivation of E. coli as a model pathogen in water. The bacterial detection limit (initial ≈106 CFU/mL) is reached using 1 gL−1 of both catalysts, 100 ppm of H2O2 under visible light (410–710 nm) and near neutral pH in 2 h, with no post‐treatment regrowth observed. Experimental data are analyzed according to the Chick–Watson, Weibull, and Hom disinfection kinetic models. Although more hydroxyl radicals are generated (trapping tests) and less iron leachate is observed for NZ–Fe, good reusability is attained for three disinfection cycles when NZ–Cu is used. This makes copper‐exchanged clinoptilolite a suitable and low‐cost photocatalyst for water disinfection through heterogeneous photo‐Fenton‐type processes.

Fe and Cu exchanged natural clinoptilolites are evaluated as heterogeneous photo‐Fenton catalysts for water disinfection under visible light, using E. coli as a model pathogen. Bacterial detection limit is reached in 2 h, with no regrowth observed. The kinetics of the reaction, the hydroxyl radicals generation, and the reuse of the catalysts are studied. Faster kinetics and better reusability is found in Cu‐ than in Fe‐clinoptilolite…© 2025 WILEY‐VCH GmbH