Pyrite as a sustainable catalyst in electro-Fenton process for improving oxidation of sulfamethazine. Kinetics, mechanism and toxicity assessment /Natija Barhoumi a, b , Nihal Oturan b , Hugo Olvera-Vargas b , Enric Brillas c, ** , Abdellatif Gadri a , Salah Ammar a, d , Mehmet A. Oturan b - Barhoumi,Natija