| Metadata | Details |
|---|
| Publication Date | 2022-05-31 |
| Journal | Catalysts |
| Authors | Ăngela Moratalla, Engracia Lacasa, Pablo Cañizares, Manuel A. Rodrigo, Cristina SĂĄez |
| Institutions | University of Castilla-La Mancha |
| Citations | 6 |
| Analysis | Full AI Review Included |
- Core Value Proposition: Electro-Fenton (EF) and Photoelectro-Fenton (PEF) technologies were successfully applied for the selective degradation of Penicillin G (PenG) in complex synthetic urine media, focusing on reducing chemical risk rather than achieving complete mineralization.
- Anode Performance: Boron-Doped Diamond (BDD) anodes achieved 100% PenG removal via EF, significantly outperforming Mixed Metal Oxide (MMO-IrO2Ta2O5) anodes, which reached 75.5% removal under identical soft oxidation conditions (5 mA cm-2).
- Synergistic Effect (PEF): Combining EF with UVC irradiation (PEF) showed a strong synergistic effect, particularly with the MMO anode, yielding a synergy coefficient of 166.67% (compared to 83.18% for BDD).
- Effluent Quality Improvement: EF treatment dramatically increased the biodegradability of the urine effluent (BODST increased from 0.16 to 0.80 mg O2 dm-3) by converting recalcitrant PenG into less complex, biodegradable intermediates (carboxylic acids).
- Antibiotic Activity Reduction: PEF treatment using the MMO anode achieved an 89.00% improvement in the removal of antibiotic effect (measured by E. faecalis inhibition), confirming its effectiveness as a pretreatment step.
- Energy Efficiency: Complete PenG removal and high inhibition of the antibiotic effect were achieved with a low specific energy consumption (less than 0.05 Ah dm-3) using the PEF process.
- Mechanism Insight: The selective degradation strategy favors the accumulation of aromatic and carboxylic acids as final products, justifying the lack of high mineralization but confirming the increase in biodegradability.
| Parameter | Value | Unit | Context |
|---|
| Target Pollutant | Penicillin G (PenG) | - | Model antibiotic |
| Initial PenG Concentration | 50 | mg dm-3 | Synthetic urine medium |
| Initial pH (pH0) | 3.0 | - | Adjusted for EF/PEF processes |
| Current Density (j) | 5 | mA cm-2 | Soft oxidation conditions used |
| Anode Materials Tested | MMO-IrO2Ta2O5, BDD/Nb mesh | - | Direct vs. mediated oxidation comparison |
| Cathode Materials Tested | Ti foam, Ti mesh | - | Both coated with Carbon Black/PTFE |
| Heterogeneous Catalyst | 10.8 | g | Goethite (30-50 mesh) in fluidized bed |
| Electric Charge Passed (Q) | 0.10 | Ah dm-3 | Standard charge for comparison |
| UVC Lamp Power | 9 | W | Used for Photoelectro-Fenton (PEF) |
| PenG Removal (EF, BDD/Foam) | 100 | % | Achieved complete removal |
| PenG Removal (EF, MMO/Foam) | 75.5 | % | Achieved partial removal |
| PEF Synergy Coefficient (MMO/Foam) | 166.67 | % | Highest synergy observed |
| BODST Increase (Initial Urine to EF-Treated) | 0.16 to 0.80 | mg O2 dm-3 | Significant biodegradability improvement |
| Antibiotic Effect Reduction (PEF-MMO) | 89.00 | % | Improvement over EF process |
| Specific Energy for Complete PenG Removal (PEF-BDD) | less than 0.05 | Ah dm-3 | Required for high inhibition removal |
- Electrochemical Reactor Setup: A microfluidic flow-through (MF-FT) cell was used, connected to a reservoir tank (2.7 dm-3 volume). The system included a jet aerator for oxygen supersaturation and a fluidized bed containing 10.8 g of goethite (Fe catalyst).
- Electrode Fabrication and Selection:
- Anodes: MMO mesh (IrO2Ta2O5) and BDD supported on 3D-niobium mesh were tested.
- Cathodes: 3D Titanium foam and 3D titanium mesh were used as supports, coated with a mixture of carbon black (CB, Vulcan XC72) and polytetrafluoroethylene (PTFE) for efficient H2O2 generation.
- Process Implementation: Experiments were conducted under Electro-Fenton (EF) conditions (5 mA cm-2, pH 3.0) and Photoelectro-Fenton (PEF) conditions, where a 9 W UVC lamp (254 nm) was inserted into the reservoir tank to enhance radical generation.
- Chemical Analysis:
- PenG and complex intermediates were monitored using High-Performance Liquid Chromatography (HPLC) coupled with a Time-of-Flight Mass Spectrometer (LC-MS TOF 6320).
- Mineralization was tracked via Total Organic Carbon (TOC) analysis.
- Short-chain carboxylic acids (oxalic, maleic, formic, etc.) were identified using HPLC with a Hi-Plex column.
- Microbiological Assessment:
- Toxicity: Acute toxicity was measured using the MicrotoxÂź M5000 analyzer, monitoring the inhibition of bioluminescence of Vibrio fischeri.
- Antibiotic Activity: Determined by counting Colony Forming Units (CFU) per mL, using Enterococcus faecalis as the indicator microorganism.
- Biodegradability: Measured using the Short-Term Biochemical Oxygen Demand (BODST) test with unacclimated activated sludge, tracking dissolved oxygen decay.
- Hospital and Pharmaceutical Wastewater Pretreatment: The primary application is using PEF as an efficient pretreatment step for hospital urine and wastewater heavily polluted with antibiotics, reducing the chemical risk before disposal into conventional municipal sewers (WWTPs).
- Advanced Oxidation Processes (AOPs): Integration of BDD electrode technology and UVC light for the robust and rapid degradation of recalcitrant Pharmaceutical Compounds (PhCs) in industrial effluents.
- Water Reuse and Recycling: Applicable in systems requiring the removal of trace organic contaminants and endocrine disruptors, leveraging the high efficiency of the PEF process.
- Electrochemical Reactor Design: Utilization of the optimized MF-FT cell design, coupled with 3D metallic foam/mesh cathodes, for scalable and cost-effective electro-generation of H2O2 in flow-through systems.
- BDD Electrode Manufacturing: Confirms the superior performance of BDD anodes in generating highly reactive species for contaminant degradation, even under low current density (soft oxidation) conditions.
View Original Abstract
The viability of the Electro-Fenton (EF) process in the selective degradation of penicillin G (PenG) in complex solutions has been studied. The role of the anode material (boron-doped diamond (BDD) or mixed metal oxide (MMO)) and the cathode 3D support (foam or mesh), as well as the synergistic effect of UVC light irradiation (photoelectron-Fenton, PEF), have been evaluated. The results show that Pen G can be efficiently and selectively removed by EF, obtaining higher PenG removal rates when using the BDD anode (100%) than when using the MMO anode (75.5%). Additionally, mineralization is not favored under the experimental conditions tested (pH 3, 5 mA cmâ2), since both aromatic and carboxylic acids accumulate in the reaction system as final products. In this regard, the EF-treated solution presents a high biological oxygen demand and a low percentage of Vibrio fischeri inhibition, which leads to high biodegradability and low toxicity of this final effluent. Furthermore, the combination with UVC radiation in the PEF process shows a clear synergistic effect on the degradation of penicillin G: 166.67% and 83.18% using MMO and BBD anodes, respectively. The specific energy required to attain the complete removal of PenG and high inhibition of the antibiotic effect is less than 0.05 Ah dmâ3. This confirms that PEF can be efficiently used as a pretreatment of conventional wastewater treatment plants to decrease the chemical risk of complex solutions polluted with antibiotics.
- 2019 - Pharmaceuticals of Emerging Concern in Aquatic Systems: Chemistry, Occurrence, Effects, and Removal Methods [Crossref]
- 2021 - Novel Ti/RuO2IrO2 anode to reduce the dangerousness of antibiotic polluted urines by Fenton-based processes [Crossref]
- 2006 - Toxicity and biodegradability assessment of raw and ozonated procaine penicillin G formulation effluent [Crossref]
- 2014 - Electro-Fenton degradation of the antibiotic sulfanilamide with Pt/carbon-felt and BDD/carbon-felt cells. Kinetics, reaction intermediates, and toxicity assessment [Crossref]
- 2021 - Photocatalytic performance of Ti/MMO/ZnO at degradation of levofloxacin: Effect of pH and chloride anions [Crossref]
- 2019 - The impact of on-site hospital wastewater treatment on the downstream communal wastewater system in terms of antibiotics and antibiotic resistance genes [Crossref]
- 2017 - Degradation of pharmaceutical diclofenac and ibuprofen in aqueous solution, a direct comparison of ozonation, photocatalysis, and non-thermal plasma [Crossref]
- 2021 - Degradation of micropollutant cephalexin by ultraviolet (UV) and assessment of residual antimicrobial activity of transformation products [Crossref]