New insight into the adsorption of sulfadiazine on graphite-like biochars prepared at different pyrolytic temperatures

This study investigated the adsorption of sulfadiazine (SDZ) with four biochars prepared at 600, 700, 800 and 900 degrees C, and probed the potential rule connecting their chemical properties and adsorption capacities. Results showed that increasing the pyrolytic temperature, specific surface area, pore volume, aromaticity and aromatic cluster lateral size (La) of biochar markedly improved its adsorption capacity for SDZ. The maximum adsorption capacities (qm) of biochar600, biochar700, biochar800 and biochar900 for SDZ were 3.44, 17.87, 86.13 and 206.03 mgg  1 preparation, beyond which the La of biochar rapidly expanded. Compared with the pyrolytic temperature, specific surface area, pore volume and aromaticity of biochar, the La values of the four biochars exhibited a good positive linear correlation with their qm, indicating for the first time that La is an effective indicator to predict the adsorption capacity of graphite-like biochar. Density functional theory calculation further revealed that larger aromatic clusters could accommodate more SDZ molecules, and that the interaction among SDZ molecules in turn increased their binding energy with biochar. These findings in this study provide useful information for designing various efficient biochar adsorbents in the future. , respectively. The pyrolytic temperature of 700 degrees C was the key temperature for the graphite-like biochar

Automated summary

This study investigates the adsorption of sulfadiazine (SDZ) by biochars prepared at different temperatures and explores the connection between their chemical properties and adsorption capacities. The results show that higher pyrolytic temperature and certain chemical properties of biochar significantly improve its adsorption capacity for SDZ. The study also introduces the lateral size (La) of aromatic clusters in biochar as an effective indicator for predicting the adsorption capacity of graphite-like biochar. Furthermore, density functional theory calculations reveal that larger aromatic clusters accommodate more SDZ molecules, increasing their binding energy with biochar. These findings provide valuable information for designing efficient biochar adsorbents in the future.