A wheat and hemp lignin, obtained from a soda pulping-precipitation process, was carbonized at 800 degrees C under N-2 atmosphere. The resulting carbon material was thermally activated under oxidative atmosphere at four different temperatures (150, 200, 300 and 350 degrees C). The materials prepared at higher activation temperatures (300 and 350 degrees C) have proven their potential in the elimination of 4-nitrophenol (4-NP) from aqueous model solutions (5 gL(-1)) when using catalytic wet peroxide oxidation (CWPO). In these conditions we were able to remove around 70% of 4-NP after 24 h, with an efficient H2O2 decomposition, in experiments conducted at relatively mild operating conditions (atmospheric pressure, 50 degrees C, pH =3, catalyst load =2.5 g L-1 and [H2O2](0) = 17.8 g L-1). By increasing the working temperature to 80 degrees C, complete 4-NP removal was obtained within 48 h (against 93% 4-NP removal at 50 degrees C), with an efficiency of H2O2 consumption of 70% and a significant mineralization (61%). On the other hand, the materials prepared at lower activation temperatures (150 and 200 degrees C), with higher basicity, promote the faster but inefficient H2O2 decomposition, 4-NP removal being lower than 25% after 24h at 50 degrees C in CWPO. This can be attributed to the formation of species other than HO center dot radicals during H2O2 decomposition, the recombination of the formed radicals into non-reactive species and a poor adsorption capacity. (C) 2017 Elsevier B.V. All rights reserved.