Degradació d’herbicides s-triazínics mitjançant processos electroquímics d’oxidació avançada

• Autores: N. Borrás Cristofol
• Directores de la Tesis: Concha Arias Tejerina (dir. tes.)
• Lectura: En la Universitat de Barcelona ( España ) en 2013
• Idioma: catalán
• Tribunal Calificador de la Tesis: José Peral Pérez (presid.), José Antonio Garrido Ponce (secret.), Francisco Estrany Coda (voc.)
• Materias:
  • Ciencias agrarias
    • Agroquímica
      • Herbicidas
  • Ciencias tecnológicas
    • Ingeniería y tecnología químicas
      • Operaciones electroquímicas
    • Ingeniería y tecnología del medio ambiente
      • Tecnología de aguas residuales
• Enlaces
  • Tesis en acceso abierto en:  TDX  Dipòsit Digital de la UB 
• Resumen

  • SUMMARY: advanced oxidation processes are nowadays, an effective treatment for waste water polluted with agrochemicals or persistent pollutants, and also are environmentally friendly methods. In the present thesis three herbicides have been studied, atrazine, desmetrine and cyanazine , commonly used to treat crops to remove weeds. These treatments are based on oxidation processes in electrolytic cell with an anode of boron-doped diamond (BDD) and a stainless steel cathode or an oxygen diffusion cathode. BDD anode has been very effective for this purpose since it has a high resistence in many media and has a high oxygen overpotential. Studied conditions for the degradation were carried out taking into account the influence of the pH of the medium, temperature and the presence of catalysts. The methods applied are anodic oxidation, electro- photo and photo electro- Fenton. In the case of Fenton treatment, the necessary hydrogen peroxide to take place the Fenton reaction has been electrogenerated with an air diffusion cathode. In the photo electro -Fenton method, the solution was irradiated with a UV black light lamp. The results demonstrate that the most effective method in all cases is the photo electro-method, because there is a synergy between the oxidizing power of electro- Fenton method and the degradation capacity of ultraviolet radiation on some degradation intermediates. The study also comprises a tracking of all intermediates generated during mineralization by spectrophotometric and chromatographic techniques , and a kinetic study for every herbicide . Finally a degradation pathway is proposed for the three herbicides consistent with experimental results.