State-of-the-Art on the Sulfate Radical-Advanced Oxidation Coupled with Nanomaterials: Biological and Environmental Applications

Progress and Perspectives on Pyrite-Derived Materials Applied in Advanced Oxidation Processes for the Elimination of Emerging Contaminants from Wastewater

Emerging contaminants (ECs) in wastewater threaten environmental and human health, while conventional methods often prove inadequate. This has driven increased concern among decision makers, justifying the need for innovative and effective treatment approaches. Pyrite-derived materials have attracted great interest in advanced oxidation processes (AOPs) as catalysts because of their unique Fe-S structure, ability to undergo redox cycling, and environmental friendliness. This review explores recent advances in pyrite-derived materials for AOP applications, focusing on their synthesis, catalytic mechanisms, and pollutant degradation. It examines how pyrite activates oxidants such as hydrogen peroxide (H2O2), peracetic acid (PAA), and peroxymonosulfate (PMS) can be used to generate reactive oxygen species (ROS). The role of multi-dimensional pyrite architectures (0D-3D) in enhancing charge transfer, catalytic activity, and recyclability is also discussed. Key challenges, including catalyst stability, industrial scalability, and Fe/S leaching, are addressed alongside potential solutions. Future directions include the integration of pyrite-based catalysts with hybrid materials, as well as green synthesis to improve practical applications. This review provides researchers and engineers with valuable insights into developing sustainable wastewater treatment technologies.

The salty tango of brine composition and UV photochemistry effects on Halobacterium salinarum cell envelope biosignature preservation

Hypersaline environments, including brines and brine inclusions of evaporite crystals, are currently of great interest due to their unique preservation properties for the search for terrestrial and potentially extraterrestrial biosignatures of ancient life. However, much is still unclear about the specific effects that dictate the preservation properties of brines. Here we present the first insights into the preservation of cell envelope fragments in brines, characterizing the relative contributions of brine composition, UV photochemistry, and cellular macromolecules on biosignature preservation. Cell envelopes from the model halophile Halobacterium salinarum were used to simulate dead microbial cellular remains in hypersaline environments based on life as we currently know it. Using different Early Earth and Mars analogue brines, we show that acidic and NaCl-dominated brine compositions are more predisposed to preserving complex biosignatures from UV degradation, but that the composition of the biological material also influences this preservation. Furthermore, a combinatory effect between chaotropicity and photochemistry occurs, with the relative importance of each being brine-specific. These results provide an experimental framework for biosignature detection in hypersaline environments, emphasizing the need for laboratory simulations to evaluate preservation properties of each potential brine environment, on Earth and elsewhere in the solar system.

Degradation of Remazol Brilliant Blue Dye Using Persulfate Activated by Fe3O4@PDA Nanoparticles: Kinetic Studies, Radical Determination, and Phytotoxicity Test

In the current research work, an advanced oxidation process was applied to the degradation of Remazol brilliant blue dye (RBBD) using a sulfate radical. Fe3O4@PDA nanoparticles were synthesized using coprecipitation and self-polymerization techniques. Nanoparticle formation was confirmed by XRD, FTIR, FESEM-EDX, VSM, and XPS analyses. The crystalline nature of the material showed that it possessed a spherical shape with an Ms value of 58 emu/g. The elemental composition and binding energy from EDX and XPS analyses showed successful doping. Batch studies were conducted, and experimental studies showed that the optimum condition for degradation of 90 ppm of RBBD was 0.3 g/L of nanomaterial, 20 mM PS at pH 3, achieving 91.35% degradation. The kinetic model suitable for this study was a pseudo-second-order kinetic model with R2 value >0.9. From the radical identification tests, sulfate radicals played a dominant role in degradation, and to confirm it, EPR analysis was conducted using DMPO. A stability test was performed for 5 cycles in which the degradation efficiency was reduced appreciably. From XPS, XRD, and EDX analyses, the elemental composition and oxidation state of the recycled material used in the fifth cycle showed variation in a negligible manner when compared to the fresh catalyst used in the first cycle of the degradation experiment. Intermediate identification was done by GCMS analysis, and it disclosed the formation of aliphatic products from the degradation of RBBD with less toxicity. Phytotoxicity analysis was conducted using green grams for 10 days, and it proved that intermediates formed in the solution were nontoxic to the plants. Additionally, TOC and COD removal % were attained to be 80.021 and 80.903%, respectively, which confirm the mineralization efficacy. Hence, this research work proved the efficient performance of the catalyst for RBBD degradation with less formation of intermediates, and therefore, this technique is most suitable for the reduction of water pollution.

Antibiotic removal from synthetic and real aqueous matrices by peroxymonosulfate-based advanced oxidation processes. A review of recent development

The widespread use of antibiotics for the treatment of bacteriological diseases causes their accumulation at low concentrations in natural waters. This gives health risks to animals and humans since it can increase the damage of the beneficial bacteria, the control of infectious diseases, and the resistance to bacterial infection. Potent oxidation methods are required to remove these pollutants from water because of their inefficient abatement in municipal wastewater treatment plants. Over the last three years in the period 2021-September 2023, powerful peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) have been developed to guaranty the effective removal of antibiotics in synthetic and real waters and wastewater. This review presents a comprehensive analysis of the different procedures proposed to activate PMS-producing strong oxidizing agents like sulfate radical (SO4•-), hydroxyl radical (•OH, radical superoxide ion (O2•-), and non-radical singlet oxygen (1O2) at different proportions depending on the experimental conditions. Iron, non-iron transition metals, biochar, and carbonaceous materials catalytic, UVC, photocatalytic, thermal, electrochemical, and other processes for PMS activation are summarized. The fundamentals and characteristics of these procedures are detailed remarking on their oxidation power to remove antibiotics, the influence of operating variables, the production and detection of radical and non-radical oxidizing agents, the effect of added inorganic anions, natural organic matter, and aqueous matrix, and the identification of by-products formed. Finally, the theoretical and experimental analysis of the change of solution toxicity during the PMS-based AOPs are described.