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The presence of personal care product (PCP) residues in the aquatic environment is an emerging issue due to their uncontrolled release through graywater; for this reason, efforts are being made to develop methods to inactivate or eliminate this class of substances in the environment. In this work, homogeneous photocatalysis has been applied for the degradation of UV filter para-aminobenzoic acid (PABA), which exists in several types of PCPs, in order to identify the optimum degradation conditions. The oxidation of PABA by photo-Fenton and oxalate-induced photo-Fenton (ferrioxalate) processes was investigated, and the effect of various operating variables has been assessed, i.e., Fe (0.0035-0.014 g L), HO (0.025-0.2 g L), T (280-323 K), and type of radiation (UV-A, visible). Furthermore, experiments under optimal conditions have been performed in order to evaluate the transformation pathways and phytotoxicity of the treated PABA solution.

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BACKGROUND: The presence of pharmaceutical and personal care products' (PPCPs) residues in the aquatic environment is an emerging issue due to their uncontrolled release, through grey water, and accumulation in the environment that may affect living organisms, ecosystems and public health. As a result, efforts are being made to develop methods to inactivate or eliminate this class of substance in the environment.

BACKGROUND: Liquid hazardous medical wastes (LHMW) originating from health-care laboratory services present a global environmental hazard as most sustainable wastewater treatment technologies fail to address this particularly demanding issue. In this study, heterogeneous and homogeneous photocatalytic oxidation of simulated and real LHMW has been performed at bench scale, investigating their potential to decompose and detoxify such effluents.RESULTS: A simulated LHMW of 0.4 g L −1 DOC 0 was photocatalytically treated in the presence of TiO 2 P25. The addition of H 2 O 2 was necessary to achieve mineralization, while the optimal concentration of P25 for this purpose was 1.0 g L −1 . In the case of photo-Fenton, under optimal conditions (0.056 g L −1 Fe 3+ , 3 g L −1 H 2 O 2 , UV-A, pH 3.0) complete mineralization was accomplished in 600 min of illumination, while phytotoxicity was eliminated or significantly reduced, depending on the employed plant species. Photocatalytic processing of real LHMW (400 mg L −

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BACKGROUND Pharmaceutically active compounds, emerging extensively in ecosystems as pollutants, have become an important environmental and public health issue, since they can contaminate drinking water and pose threats to wildlife and human health. As a result, efforts should be made to develop methods to inactivate or eliminate this class of substance in the environment. RESULTS The photocatalytic degradation of psychoactive drug Fluvoxamine has been investigated. In the case of heterogeneous photocatalytic oxidation, the effect of TiO2 P25 concentration (0.1–1 g L‐1), initial concentration of H2O2 (0.25–0.2 g L‐1) and Fe3+ (0.00175–0.014 g L‐1) and pH of the solution on initial reaction rates were evaluated, while for homogeneous photocatalytic oxidation the effect of the amount of H2O2 (0.25–0.2 g L‐1) and Fe3+ (0.00175–0.014 g L‐1) were investigated. In addition, the conversion of the heteroatoms in the FVX molecule to inorganic ions (NO3‐, NH4+, F‐) during the photocatalytic process has been observed and phytotoxicity testing, using three plant species, was carried out in order to examine the effect of photocatalytic oxidation on the toxicity of FVX. CONCLUSION According to the results presented in this study, both heterogeneous and homogeneous photocatalytic oxidation is an efficient methodology for FVX degradation. © 2017 Society of Chemical Industry

Photocatalytic inactivation of pathogens in aqueous waste is gaining increasing attention. Several homogeneous and heterogeneous photocatalytic protocols exist using the Fenton’s reagent and TiO2, respectively. A comprehensive study of homogeneous and heterogeneous photocatalysis on a range of microorganisms will significantly establish the most efficient method. Here, we report a comparative study of TiO2- and Fe+3-based photocatalytic inactivation under UV-A of diverse microorganisms, including Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, bacterial spores (Bacillus stearothermophilus spores) and viruses (MS2). We also present data on the optimization of TiO2 photocatalysis, including optimal catalyst concentration and H2O2 supplementation. Our results indicate that both photo-Fenton and TiO2 could be successfully applied for the management of microbial loads in liquids. Efficient microorganism inactivation is achieved with homogeneous photocatalysis (7 mg/L Fe+3, 100 mg/L H2O2, UV-A) in a shorter processing time compared to heterogeneous photocatalysis (0.5 g/L TiO2, UV-A), whereas similar or shorter processing is required when heterogenous photocatalysis is performed using microorganism-specific optimized TiO2 concentrations and H2O2 supplementation (100 mg/L); higher H2O2 concentrations further enhance the heterogenous photocatalytic inactivation efficiency. Our study provides a template protocol for the design and further application for large-scale photocatalytic approaches to inactivate pathogens in liquid biomedical waste.