A novel modeling approach for a generalizable photo-Fenton-based degradation of organic compounds

Francesca Audino,Monika Varga,Montserrat Pérez-Moya,Moisès Graells,Bela Csukas,Antonio Espuña

doi:10.1007/s11356-020-08616-4

Francesca Audino, Monika Varga + Show 4 more

Open Access

https://doi.org/10.1007/s11356-020-08616-4

Copy DOI

Abstract

This work aims at proposing and validating a model that can be exploited for the future development of industrial applications (e.g., process design and control) of Fenton and photo-Fenton processes. Hence, a compromise modeling solution has been developed between the non-generalizable accuracy of the first principles models (FPMs) and the oversimplification of the empirical models (EMs). The work presents a novel model of moderate complexity that is simplified enough to be generalizable and computationally affordable, while retaining physical meaning. The methodology is based on a general degradation mechanism that can be algorithmically generated from the carbon number of the target compound, as well as from the knowledge of two kinetic parameters, one for the faster initial rate and the other one for the subsequent degradation steps. The contaminant degradation mechanism has been combined with an appropriately simplified implementation of the well-known Fenton and photo-Fenton kinetics. This model describes the degradation not only of the target compound and of the oxidant, but also of total organic carbon (TOC), which is used to define the overall quality of the water. Experimental design techniques were used along with a non-conventional modeling methodology of programmable process structures (PPS). This novel modeling approach was applied and validated on the degradation of three model compounds. A successful prediction of the evolution of the contaminants H2O2 and TOC was confirmed and assessed by the root mean square error (RMSE).

Highlights

A notable experimental effort has been spent in the last 20 years in investigating the advanced oxidation processes (AOPs), being an effective alternative to conventional biological processes for the treatment of toxic and recalcitrant wastewaters, and for the removal of contaminants of emerging concern (CECs) (Miklos et al 2018).Responsible editor: Vítor Pais VilarA recent review by Mazivila et al (2019) presents an interesting overview on AOPs, dividing them into a classical approach with emphasis on Fenton, photo-Fenton, and ozonation processes, all based on the generation of highly reactive hydroxyl radicals, and a novel approach
Among the new perspectives of AOPs, there are the ones based on the generation of emerging reactive sulfate (SO4·−) radicals, advanced electrochemical oxidation technologies, nanocatalytic heterogeneous Fenton technology, and semiconductor photocatalysis (TiO2/UV), as well as the combination of processes involving at least one AOP
Once the model was formulated and the experimental designs were proposed for the selected model compounds, it was possible to proceed to the model training and validation step

Summary

Introduction

A notable experimental effort has been spent in the last 20 years in investigating the advanced oxidation processes (AOPs), being an effective alternative to conventional biological processes for the treatment of toxic and recalcitrant wastewaters, and for the removal of contaminants of emerging concern (CECs) (Miklos et al 2018). A recent review by Mazivila et al (2019) presents an interesting overview on AOPs, dividing them into a classical approach with emphasis on Fenton, photo-Fenton, and ozonation processes, all based on the generation of highly reactive hydroxyl radicals, and a novel approach. Among the new perspectives of AOPs, there are the ones based on the generation of emerging reactive sulfate (SO4·−) radicals, advanced electrochemical oxidation technologies (such as electroFenton and electro-photo-Fenton), nanocatalytic heterogeneous Fenton technology, and semiconductor photocatalysis (TiO2/UV), as well as the combination of processes involving at least one AOP.

Objectives

Results

Conclusion