Assessment of biochars obtained at two different pyrolysis temperatures to mitigate pollution due to Lumax®

New strategies, such as biochar soil amendment, are continuously developed to restore the agricultural environment from the adverse effects of agrochemicals. The sorption efficiency of a biochar depends on the specific raw materials and pyrolysis variables applied, such as temperature and heating time, that shape its physico-chemical properties. In this study, the sorption capacity of two biochars obtained from coppiced hardwoods at two different pyrolysis temperatures (650 degrees C and 1100 degrees C, denominated BCLT and BCHT, respectively) was assessed for Lumax (R), a pre-emergence selective herbicide used for maize cultivation. Lumax (R) is composed of S-metolachlor (MTC), terbuthylazine (TBZ), and mesotrione (MST), therefore the sorption behaviour of active ingredients, alone or mixed as in the commercial formulation, was studied on two biochar samples to identify the best product to mitigate Lumax (R) pollution. Our results show that, although biochar performance depends on the physico-chemicals properties of both the biochar and the pollutants, BCHT was the most suitable in retaining the Lumax (R) active ingredients, likely due to its high aromaticity.