Publication

Degradation of a biorecalcitrant dye precursor present in industrial wastewaters by a new integrated iron(III) photoassisted-biological treatment

Abstract

This study focuses on the mineralization of 5-amino-6-methyl-2-benzimidazolone (AMBI), an important precursor in the industrial production of dyes, through an integrated Fe(III) photoassisted–biological system without addition of other electron acceptor than O2. The iron photoassisted process produces a biocompatible solution, removing 100% of the initial biorecalcitrant compound and 40% of the Dissolved Organic Carbon (DOC), and then the complete mineralization was achieved in the biological treatment. The transformation of AMBI photoinduced by only Fe(III) is mainly attributed to three simultaneous process: direct photolysis of the [Fe3+–AMBI] complex, the attack of the complex by √OH radicals generated by the photolysis of Fe(OH)2+, and by the attack of supplementary √OH radicals generated by the Fenton and photo-Fenton like reactions, which are induced by the H2O2 that have been formed “in situ”. The following topics are also studied in this paper: (a) the UV-Vis spectroscopic characterization of Fe(III), AMBI, and its mixture in aqueous solution, (b) the involvement of √OH radicals and oxygen in the photodegradation of AMBI, (c) the comparison between O2 and H2O2 as electron acceptors in the iron photoassisted pretreatment, and their performances as a pretreatment step in the coupled photochemical biological reactor. Some field experiments under direct solar radiation were carried out using a compound parabolic collector (CPC) erected at the Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland. The obtained results indicate that a coupled solar–biological treatment system at pilot scale is a possible way to achieve the complete mineralization of biorecalcitrant pollutants.

About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Graph Chatbot

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.