Quinoline (QN) is highly toxic and carcinogenic and has been detected in soil, groundwater,
and biological tissues. Advanced oxidation processes (AOPs) have shown promise to address its
degradation in wastewater treatment, with catalytic wet peroxide oxidation (CWPO) being highlighted
due to its cost-effectiveness and mild operation. However, developing active and inexpensive catalysts
is crucial for CWPO’s effectiveness. Another pressing issue is the accumulation of mixed, dirty plastic
solid waste (PSW), particularly polyolefins used in packaging. Although recycling rates have increased,
much plastic packaging remains in landfills. However, polyolefins can be converted into carbon-based
nanostructured materials (CNMs), such as carbon nanotubes (CNTs), through chemical vapor deposition
(CVD) using PSW as a carbon precursor. While many studies focus on CNT preparation, their application
is often overlooked. In this context, this work proposes the preparation of CNMs, particularly CNTs,
through CVD using a single-stage pyrolysis reactor. Polyolefins (LDPE, HDPE, and PP), both individually
and in a mixture simulating PSW, were used as carbon sources. Given a sufficiently high temperature,
the desired CNT architecture was successfully synthesized regardless of the starting polymer. These
CNMs were then tested as catalysts for CWPO in simulated wastewater containing QN. The results
showed a rapid degradation of QN (30–120 min) and high removals of total organic carbon (TOC) and
aromatic compounds (75% and >90%, respectively), demonstrating the applicability of PSW-derived
CNTs in the CWPO process for QN abatement.
This work was financially supported by LA/P/0045/2020 (ALiCE), UIDB/50020/2020 and
UIDP/50020/2020 (LSRE-LCM) funded by national funds through FCT/MCTES (PIDDAC), and CIMO
(UIDB/00690/2020) through FEDER under Program PT2020, project “PLASTIC_TO_FUEL&MAT—
Upcycling Waste Plastics into Fuel and Carbon Nanomaterials” (PTDC/EQU-EQU/31439/2017). Fer-
nanda F. Roman acknowledges the national funding from the FCT and the European Social Fund, FSE,
through the individual research grant SFRH/BD/143224/2019. Adriano Santos Silva thanks the FCT for
financial support under the MIT Portugal Program with doctoral grant SFRH/BD/151346/2021. J. L.
Diaz de Tuesta acknowledges the research grants (2022-T1/AMB-23946) from the program of Atracción
al Talento of Comunidad de Madrid (Spain)
