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Phthalates are widely used plasticizers, but have endocrine-disrupting effects, which cause harm to both humans and the wider environment. Photocatalytic technologies have been shown to be promising methods for removal of a range of environmental pollutants in water. In this paper the photocatalytic oxidation of Diisobutyl phthalate (DiBP) using two common commercial catalysts, TiO2 and ZnO is assessed. Both photocatalysts proved to be effective in removing > 90% of the compound in less than 25 min of treatment. Pseudo-first kinetics were initially used to describe the kinetics of the process, but were found to poorly describe the kinetics, which was believed to be a result of not accounting for the influence of intermediates. A new kinetic model is proposed to account for intermediate formation, which described the experimental data better. In addition, the incorporation of acoustic cavitation (AC) with photocatalysis (PC) was tested for DiBP degradation. The hybrid process enhanced the DiBP degradation rate and a synergistic index of 1.5 and 2.2 observed for TiO2 and ZnO respectively. The effect of pH on DiBP degradation was investigated and it showed that on both photocatalysts, reaction rates were higher when pH was greater than the point of zero charge for the photocatalyst. These results demonstrated the feasibility of hotocatalysis for DiBP removal and the potential of AC to enhance the PC process for removal of phthalates from water. This new kinetic model proposed will be useful for the design of AOP based water treatment as it predicts the kinetics of the process more accurately than the commonly used pseudo first order kinetic model.

Cyanobacteria and their toxic secondary metabolites present challenges for water treatment globally. In this study we have assessed TiO immobilized onto recycled foamed glass beads by a facile calcination method, combined in treatment units with 365 nm UV-LEDs. The treatment system was deployed in mesocosms within a eutrophic Brazilian drinking water reservoir. The treatment units were deployed for 7 days and suppressed cyanobacterial abundance by 85% while at the same time enhancing other water quality parameters; turbidity and transparency improved by 40 and 81% respectively. Genomic analysis of the microbiota in the treated mesocosms revealed that the composition of the cyanobacterial community was affected and the abundance of Bacteroidetes and Proteobacteria increased during cyanobacterial suppression. The effect of the treatment on zooplankton and other eukaryotes was also monitored. The abundance of zooplankton decreased while Chrysophyte and Alveolata loadings increased. The results of this proof-of-concept study demonstrate the potential for full-scale, in-reservoir application of advanced oxidation processes as complementary water treatment processes. [Abstract copyright: Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.]

BACKGROUND With an increase in global bioenergy production, the ‘biorefinery concept’ has now become a significant focus of research. The desire to achieve efficient conversion of biomass material into both energy and value‐added products requires a combination of technologies and processes. As such, the photocatalytic reforming of feedstocks such as glycerol to hydrogen (H2) has a lot of potential. RESULTS Reported here is the first example of a thin film‐based photocatalytic system capable of achieving H2 evolution using a glycerol feedstock. Using a titania (TiO2) sol–gel, glass columns were coated with a thin TiO2 layer before using photodeposition to add platinum (Pt) as a co‐catalyst. The coated columns were assembled into a simple yet effective recirculating system which used low power UV irradiation. Under optimum conditions (two coated columns and a 40 mL min−1 flow rate), a steady state of 0.9 μmol min−1 H2 with a photonic efficiency [ηphoton (%)] of 10.22 % was achieved. Furthermore, only one column showed flaking and loss of coating whereas the remaining columns were stable for the duration of the study, which equated to > 100 h of experimental testing including replicates and determining optimal parameters. CONCLUSION H2 evolution via photocatalytic glycerol reforming in a Pt‐TiO2 thin film catalyst recirculating system has been demonstrated under UV irradiation and ambient conditions. The system developed highlights that it is both catalyst development and reactor engineering that are required to continue to advance the field of photocatalysis.