Heterogeneous photo-Fenton like degradation of rhodamine B using copper loaded bentonite and H₂O₂

Abstract

Photo-Fenton like degradation of rhodamine B using copper loaded bentonite and hydrogen peroxide is reported. The catalyst has been prepared by loading copper ions on bentonite by wet impregnation method using Na₂CO₃, Cu(NO₃)₂.3H₂O and bentonite clay. On photo-Fenton treatment, the dye mineralizes into smaller ions like CO₃^2-, NO₃^-, NO₂^- etc. The photodegradation efficiency of the catalyst for the rhodamine B dye is found to be 67.92%. Under optimal conditions, the rate constant <i style="mso-bidi-font-style: normal">k</i> is 3.72 × 10^-4s^-1. A tentative mechanism involving •OH radical as an oxidant in degradation process is proposed. Involvement of ^•OH radicals as an active oxidizing agent is confirmed by the drastic reduction in rate of reaction in presence of isopropanol and butylated hydroxy toluene as radical scavengers. The reduction in reaction rate is higher with butylated hydroxy toluene as compared with isopropanol as the radical scavengers.