Synthesis of biogas-residue-based mesoporous carbons via one-step template-free method for organic and inorganic pollutants removal

Biogas-residue-based mesoporous carbons with high adsorption capacity have been successfully synthesized via a facile template-free and one-step approach by sodium amide activation and applied in the removal of organic and inorganic pollutants in wastewater for the first time in this study. A “waste” and widely available resource, biogas residue, was utilized as carbon precursor. Different mesoporous carbons were prepared by direct co-milling and activation at various conditions, among which largest surface area of 1278 m²/g and maximum adsorption of 556 mg/g on methylene blue were achieved, respectively. It is also verified to possess superior adsorption capacity on typical organic pollutant phenanthrene (112 mg/g) and typical inorganic pollutant N/P element (N, 113 mg/g; P, 12 mg/g). The results show that the prepared mesoporous carbons possess high and universal adsorption performance toward both organic and inorganic pollutants in wastewater. Finally, the adsorption mechanism such as the relationship between the adsorption capacities and characterization results was also discussed. The low-valued raw materials, convenient procedure, energy conservation, minimum pollution and corrosion, high adsorption capacity show feasible manufacture in industry.