Adsorption of sulfadiazine from water by Pedicularis kansuensis derived biochar: Preparation and properties studies

Sulfadiazine (SDZ) is an antibiotic frequently detected in natural water environments and wastewater treatment systems. Its accumulation and residue in aquatic seriously impact ecosystems and human health. Pedicularis kansuensis (PK) is an invasive species that seriously impacts the production of agriculture, forestry, and animal husbandry due to its strong adaptability and fast diffusion speed. In order to transform exotic noxious weeds into valuable resources, Pedicularis kansuensis biochar (PKBC) was prepared by pyrolyzing the stems of PK at 500 °C to adsorb SDZ effectively. The results demonstrated that the biochar material exhibited a plate-like morphology with a large specific surface area, which provided numerous adsorption sites and was conducive to SDZ adsorption. The pH value significantly affects the adsorption of SDZ on PKBC-500, with better adsorption performance in acidic environments. The adsorption capacity of PKBC for SDZ was determined to be 6.87 mg/L. The adsorption kinetics and isotherms were analyzed, and the pseudo-second-order kinetic better fitted the adsorption process of SDZ. The Freundlich equation was more appropriate for explaining the adsorption process. In summary, biochar adsorption of antibiotics was prepared using PK pyrolysis. Its raw material is inexpensive and can effectively adsorb SDZ while solving the problem of invasive plant management.