Pumice effectively removes drug waste using iron oxide nanoparticles

Greg Howard
11th October, 2025

Pumice effectively removes drug waste using iron oxide nanoparticles

This magnified image reveals the natural, sponge-like structure of pumice, a volcanic rock used here as a scaffold to hold tiny particles that clean pharmaceutical pollutants from water.

Image adapted from: Hammal, Sulaiman / CC BY (Source)

Key Findings

  • Researchers in Syria developed a new catalyst using volcanic rock and bay leaf extract to treat pharmaceutical wastewater, offering a sustainable solution
  • The catalyst effectively removed over 92% of organic pollutants (COD and BOD5) and completely degraded the antibiotic amoxicillin within three hours under mild conditions
  • The catalyst remained stable and reusable for at least five cycles with no harmful byproducts detected, making it a promising option for large-scale wastewater treatment
Pharmaceuticals in wastewater represent a growing threat to both the environment and human health, as conventional treatment plants often fail to completely remove these compounds[2]. These substances, even at low concentrations, can have adverse effects on aquatic life and potentially contribute to antibiotic resistance. Researchers at the University of Aleppo, in collaboration with the University of Tartous and the Indian Institute of Technology Delhi[1], have developed a new catalyst designed to tackle this problem, offering a potentially sustainable and efficient solution for pharmaceutical wastewater treatment. The core of this research lies in the creation of a nano-hybrid catalyst composed of iron oxide (Fe2O3) and manganese dioxide (MnO2) supported on acid-activated Syrian pumice. Pumice, a volcanic rock, is an abundant natural waste material, making its use in this process a key aspect of the circular economy principles employed by the team. The catalyst isn’t simply mixed together; it’s synthesized using a hydrothermal method, a process involving hot water under pressure, and crucially, utilizes Laurus nobilis leaf extract – commonly known as bay leaf – as a “bio-reducing agent”. This means the leaf extract facilitates the formation of the catalyst nanoparticles in an environmentally friendly manner, avoiding harsh chemicals. The resulting catalyst exhibits enhanced properties critical for effective wastewater treatment. Specifically, the surface area is significantly increased (214.7 m2/g) and the pore structure is optimized, with a balance of mesopores (80%) and micropores (20%). These pores provide more surface area for contaminants to interact with the catalyst, improving its efficiency. The team used a range of analytical techniques to confirm these structural improvements. The catalyst’s performance was tested on wastewater containing amoxicillin, a common beta-lactam antibiotic. Under relatively mild conditions – neutral pH, room temperature, and a moderate catalyst dosage – the system achieved impressive removal rates: 92.3% Chemical Oxygen Demand (COD) and 93.5% Biochemical Oxygen Demand (BOD5) within three hours. COD and BOD5 are measures of organic pollution in water; a higher removal percentage indicates cleaner water. Importantly, Liquid Chromatography-Mass Spectrometry (LC-MS/MS) analysis confirmed complete degradation of the amoxicillin, with no harmful intermediate byproducts detected. Intermediate products are often a concern with advanced treatment methods, as they can sometimes be more toxic than the original contaminant. This research builds on existing efforts to improve wastewater treatment. Conventional methods struggle with contaminants of emerging concern due to their persistence and complex chemical structures[2]. Therefore, advancements often involve combining biological treatment with advanced oxidation processes, as seen in the treatment of hospital wastewater with a combination of bioreactors and photocatalysis[3]. The catalyst developed in this study, however, utilizes a different approach – leveraging the power of nano-materials and persulfate activation. The catalyst’s robustness is another significant advantage. It retained over 86% of its efficiency after five reuse cycles, demonstrating its long-term viability. Furthermore, minimal metal leaching (iron and manganese levels below World Health Organization limits) was observed, addressing potential environmental concerns associated with nano-material use. Machine learning techniques have also been successfully applied to optimize adsorption processes for antibiotics like ciprofloxacin[4], highlighting the potential for further refinement of this catalyst’s performance through similar data-driven approaches. Finally, the study demonstrated the catalyst’s scalability by testing it in a continuous-flow mode, maintaining high COD and BOD5 removal rates (89.6% and 90.4% respectively). This is crucial for real-world application, as it shows the catalyst can be effectively used in larger-scale wastewater treatment facilities. By valorizing a locally available waste material like pumice and employing an environmentally friendly synthesis route, this research offers a promising, industrially viable solution to the growing problem of pharmaceutical contamination in wastewater.

EnvironmentSustainabilityBiochem

References

Main Study

1) Green synthesis of Fe2O3-MnO2 nano-hybrids on pumice for complete degradation of pharmaceutical pollutants

Published 10th October, 2025

https://doi.org/10.1371/journal.pone.0334324

Related Studies

2) Limitations of wastewater treatment plants in removing trace anthropogenic biomarkers and future directions: A review.

https://doi.org/10.1016/j.ecoenv.2024.116610

3) Combination of advanced biological systems and photocatalysis for the treatment of real hospital wastewater spiked with carbamazepine: A pilot-scale study.

https://doi.org/10.1016/j.jenvman.2023.119672

4) A novel interpretable machine learning and metaheuristic-based protocol to predict and optimize ciprofloxacin antibiotic adsorption with nano-adsorbent.

https://doi.org/10.1016/j.jenvman.2024.122614


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