Abstract
Pillared clays with Zr and Fe/Cu/Zr polycations have been prepared from natural clays found in large deposits of Kazakhstan and assessed as catalysts for the catalytic wet peroxide oxidation (CWPO), using 4-nitrophenol (4-NP) as model compound.The performance of the catalysts was followed by measuring the concentration of 4-NP, H2O2 and the total organic carbon (TOC), considering C4-NP = 5 g L -1 , CH 2 O 2 = 17.8 g L -1 , Ccat = 2.5 g L -1 , initial pH = 3.0 and T = 50°C.At those selected conditions, the pillared clays showed higher activity than natural clays in the CWPO of 4-NP.The conversion of the model pollutant was complete when Fe/Cu/Zr-PILCs were used, with the TOC removal reaching 78.4% after 24 h with the best Fe/Cu/Zr-PILC.The H2O2, 4-NP and TOC time-evolution was well described by a kinetic model based on TOC lumps in three blocks, considering the initial TOC (corresponding to 4-NP), the production of oxidizable intermediates and the formation of refractory products.