# Efficient Catalytic Removal of Polycyclic Aromatic Hydrocarbons from Produced Water Using Fe2+-Terpyridine-Modified Superparamagnetic Nanoparticles

## TL;DR

A new magnetic nanoparticle catalyst efficiently removes harmful PAHs from oil and gas wastewater, with high reusability and performance.

## Contribution

A novel Fe2+-terpyridine-modified superparamagnetic nanoparticle catalyst for PAH removal in produced water is developed and tested.

## Key findings

- The catalyst achieved an 82% reduction in total organic carbon in real produced water samples.
- The catalyst retained activity over five cycles with minimal performance loss.
- Both Fe2+ and terpyridine are essential for catalytic activity, as confirmed by control experiments.

## Abstract

This study presents the development and application of
a novel
Fe2+-supported terpyridine-modified superparamagnetic iron
oxide nanoparticle catalyst (Fe2+-Tpy@SPIONs) for the efficient
removal of polycyclic aromatic hydrocarbons (PAHs) from produced water.
The catalyst was synthesized through the coprecipitation of iron oxides,
followed by surface functionalization with a terpyridine ligand to
immobilize Fe2+, thereby enhancing its catalytic activity.
Catalytic performance was optimized by adjusting pH, temperature,
and catalyst dosage. Under the optimized conditions, the catalyst
demonstrated superior efficiency in degrading PAHs, reducing total
organic carbon (TOC) levels in real produced water samples, achieving
an 82% reduction. Reusability tests indicated that the Fe2+-Tpy@SPIONs catalyst retained its catalytic activity and structural
integrity over five consecutive cycles, with minimal performance loss,
as confirmed by scanning electron microscopy (SEM) and Fourier transform
infrared (FTIR) analyses. Control experiments further established
that the catalytic activity required the presence of both Fe2+ and terpyridine on the SPIONs surface, as neither unmodified SPIONs
nor Tpy@SPIONs alone resulted in significant PAH removal. This work
underscores the potential of Fe2+-Tpy@SPIONs as an effective,
reusable, and magnetically recoverable catalyst for large-scale environmental
remediation, particularly for treating organic pollutants in wastewater
produced by the oil and gas industry.