Application of a novel gas diffusion electrode for terbuthylazine removal by electrochemical advanced oxidation processes using a solar photoreactor at pilot scale

Abstract

The global consumption of pesticides has increased in parallel with agricultural activity. Several pesticides applied to crop fields are recognized as emerging pollutants with toxic, carcinogenic and endocrine disrupting effects on human health even at low concentrations in water. Most of these chemicals are designed to be highly persistent in the environment, thus making them difficult to be removed from water by conventional treatments. Lately, electrochemical technology has been evidenced as a highly efficient approach for the removal of recalcitrant organic compounds based on electrochemical advanced oxidation processes (EAOP). As a result of the high cost required for electrochemical processes, some technological advances have been designed to make them more economical; for example, solar radiation has been introduced as an alternative to UV lamps, giving rise to the so-called solar photoelectro-Fenton (SPEF) process. However, some challenges must be overcome for the complete development of this technology before reaching its large-scale application. The design of versatile cathodes with high performance for H2O2 production, with further use in the treatment of complex aqueous matrices at pilot scale, is a challenge that must be thoroughly studied. Thus, this project aims to produce a novel setup of gas diffusion electrode (GDE), with carbon cloth as substrate, being introduced in a filter-press reactor for the removal of a pesticide found in surface water in Spain, i.e., terbuthylazine. The performance in terms of H2O2 production will be studied by modifying the electrodes with catalysts produced during the PhD fellowship in Brazil. The electrochemical behavior of the best GDEs will be evaluated in terms of removal of pesticide present in a real freshwater matrix by means of electro-Fenton (EF), PEF and SPEF processes in a solar pilot plant. (AU)