An experimental approach to the optimization of the dosage of hydrogen peroxide for Fenton and photo-Fenton processes

• Published in: The Science of the total environment 2020-11, Vol.743, p.140402-140402, Article 140402
• Main Authors: Yu, Xiangwei, Somoza-Tornos, Ana, Graells, Moisès, Pérez-Moya, Montserrat
• Format: Article
• Language: English
• Subjects: Dissolved oxygen monitoring; Experimental design; Hydrogen peroxide consumption; Hydrogen peroxide dosage; Photo-Fenton; Recipe optimization
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.140402

The determination of the hydrogen peroxide dosage scheme that minimizes hydrogen peroxide consumption while meeting the specified treatment outcome is crucial for Fenton and photo-Fenton processes. The challenge is building a methodology that provides the optimal dosage profile. However, the lack of detailed dynamic models prevents exploiting model-based optimization methods that have proved successful in other applications. Thus, this work addresses this challenge by providing a problem formulation identifying and discussing objectives and constraints, and the nature of the optimal solution. From this point, the work presents a novel dosage model and a consequent methodology aimed at experimentally optimizing the dosage profile along a discretized time horizon following recipe optimization concepts. The approach is parallel to the numerical solution of the model-based optimization problem posed by hydrogen peroxide dosage. The proposed methodology is validated in the remediation of a Paracetamol (PCT) solution, and the obtained results are assessed and discussed in regard of the evolution of the concentration of hydrogen peroxide, the contaminant (PCT), and Total Organic Carbon (TOC). The concentration of dissolved oxygen (DO), which is also monitored, allows providing a more comprehensive explanation of the nature of the process. [Display omitted] •H2O2 dosage in photo-Fenton reactions is presented as an optimal control problem.•H2O2 profile is modelled by a grid discretizing reaction time and dosage level.•Completing the subsequent experimental plan determines the best dosage schemes.•Monitoring dissolved oxygen allows explaining results in terms of H2O2 need/excess.