Effect of sodium persulfate treatment on the physicochemical properties and catalytic activity of biochar prepared from spent malt rootlets

Biochar catalysts exhibit significant activity and stability, for the activation of sodium persulfate (SPS) and consequently the oxidation of organic contaminants. In this study, the influence of SPS on the physicochemical characteristics and catalytic activity of biochar was determined. Following intense treatment with high SPS concentration at high temperature the biochar samples were characterized and tested for the degradation of sulfamethoxazole (SMX) in water matrices. The SPS treatment was found to alter significantly the biochar's surface by dissolving the inorganic deposits and part of the organic phase. SPS was also found to increase the specific surface area and to change the acidity / basicity of the biochar. Lengthy treatments reduce the catalytic activity, an effect attributed to the oxidation of surface carbon groups, while shorter treatments result in higher activity due to the high specific surface area, enrichment of the surface with carbon groups and limited oxidation of the biochar.

Automated summary

SPS treatment significantly alters the surface characteristics and acidity/basicity of biochar, with lengthy treatment reducing catalytic activity.