Assessment of CoNi alloys as activator substrates in a degradation process

Abstract

This project has been developed into two parts. The first part involves the preparation of cobalt and nickel alloys using two electrochemical techniques: cyclic voltammetry and chronoamperometry. These were synthesized in an ionic liquid (DES) and using Si/Ti/Au pieces as working electrode. We can distinguish two types of alloys according to their composition on the covered surface; cobalt-rich (84.0 Co: 16.0 Ni) and nickel-rich (83.8 Ni: 16.2 Co). The second part is based on the study of the catalytic system and its optimization, which consists of the activation of peroxymonosulfate (PMS) by the action of the alloys previously synthesized to degrade persistent organic pollutants (POPs), in this project tetracycline (TC), by advanced oxidation processes (AOPs). TC is an antibiotic with extensive use in the intensive animal industry, as it accelerates livestock growth and therefore its production. Part of this antibiotic is not metabolized by the animal, which is excreted into the environment and represents a real problem due to its persistence and the possible development of multidrug-resistant microorganisms. Different parameters that condition the effectivity and efficiency of the catalytic process had been studied: the type of alloys used, the application of a heat treatment on the substrate, the pH conditions, the effect of the PMS concentration, the effect of visible light irradiation and the effect of the contact time with the catalyst