Influence of textural properties and iron content on the activated carbon performance for catalytic wet air oxidation of phenol

Catalytic Wet Oxidation is a promising treatment for wastewater containing refractory compounds, such as phenol. Activated carbon has demonstrated to perform as catalyst in wet oxidation, however it is not fully understood its role as catalyst. This study aims to clarify the effect of metal content, specifically iron and calcium, on the performance of a commercial activated carbon. Several modification of the activated carbon surface has been conducted and then calcium or iron has been supported on the modified materials. Then, the activated carbons were tested for the catalytic wet oxidation of phenol in a trickle bed system operating at 140oC and 2 bar of oxygen partial pressure, with a space time of 0.12 hours. Activated carbons containing iron have given higher conversion, than the parent activated carbon, respectively 75 and 45%. However, a significant leaching was observed, which was limited for the iron containing activated carbon previously treated with nitric acid. In turn, no improvement was obtained from the activated carbons when calcium was added.