Photoinduced transformation of waste-derived soluble bio-based substances

[EN] Waste-derived, soluble bin-based substances (SBO), are effective low-cost photosensitizers that could find application in pollutant photodegradation. For this reason, it is important to understand if and to what extent irradiation could modify their properties. The exposure of SBO to simulated sunlight induced important spectral and structural modifications. Both the whole material and its acid-soluble fraction were characterized, highlighting several properties in common with humic and fulvic substances, including absorption spectra, specific absorbance and fluorescence behavior. The latter was described with a three-component model using PARAFAC analysis. Irradiation induced SBO photobleaching, but the absorbance of the acid-soluble fraction increased with irradiation. This finding suggests a progressive photochemical solubilization of SBO, which is confirmed by the increase of the carboxylic groups. In addition to absorbance, the fluorescence of whole SBO was also decreased by irradiation, thereby suggesting that both chromophores and fluorophores were photodegraded. The increasingly hydrophilic character given to SBO by irradiation also accounted for the photoinduced decrease of the surfactant properties of the material. (C) 2015 Elsevier B.V. All rights reserved.This work was funded by the 7thFP IRSES-2010-269128-EnvironBos Marie Curie Action and by Ministero delle Politiche Agricole e Forestali (Agrienergia project). The authors are grateful to the following private and/or public Italian institutions: (a) Acea Pinerolese Spa in Pinerolo (TO) for supplying the SBO sourcing materials; (b) Studio Chiono ed Associati in Rivarolo Canavese (TO) for making available pilot equipment and services for the production of the SBO.Avetta, P.; Berto, S.; Bianco Prevot, A.; Minella, M.; Montoneri, E.; Persico, D.; Vione, D.... (2015). Photoinduced transformation of waste-derived soluble bio-based substances. Chemical Engineering Journal. 274:247-255. https://doi.org/10.1016/j.cej.2015.03.126S24725527

Natural Organic Matter Removal by Heterogeneous Catalytic Wet Peroxide Oxidation (CWPO)

NOM usually reaches drinking water supply sources through metabolic reactions and soil leaching. It has been, in general, considered that NOM is still one of the most problematic contaminants present in this kind of influents. Therefore, in the present chapter, most relevant technologies used for removal of NOM and its constituents from water have been examined, emphasizing in the past few years. An overview of the recent research studies dealing the NOM removal by catalytic wet peroxide oxidation and other closely related heterogeneous Fenton-like AOPs is presented. As revealed from recent literature reports, heterogeneous Fenton processes including CWPO are still emerging, promising catalytic technologies for NOM removal from water. A wide variety of catalytic solids reported within the past few years has been examined focusing on their potential in the NOM removal from water. Main findings offered by several types of catalysts like zeolites, Fe-functionalized activated carbons, carbon nanotubes, but mainly pillared and other clay minerals have been critically discussed emphasizing on the NOM removal by CWPO

Separation and Characterization of NOM Intermediates Along AOP Oxidation

Removal of natural organic matter (NOM) in drinking water treatment systems has been a matter of thorough study in recent years. NOM affects organoleptic properties of water and causes membrane fouling; it may act as energy source for microorganisms in distribution systems and leads to the formation of undesired disinfection by-products through its interaction with chlorine. Currently the role played by advanced oxidation processes in the removal of NOM has gained great interest; understanding the composition and behaviour of NOM throughout such a kind of processes may allow to get significant insight in order to improve efficiency. In this chapter the main techniques useful for characterization are described, and their use to investigate the changes undergone by NOM throughout several AOPs has been reviewed