Effects of aging methods on the adsorption of antibiotics in wastewater by soybean straw biochar.

Abstract

The environmental pollution and ecological risks caused by the widespread use of antibiotics have attracted attention in recent years. Biochar materials have a rich pore diameter and can effectively adsorb pollutants from wastewater. However, biochar will experience high temperatures, freezing, and thawing in nature, affecting its physicochemical properties and adsorption capacity. Three types of aged biochar were prepared by artificial simulated aging using soybean straw as raw material. The aged biochar's elemental composition and functional group species were investigated by characterization analysis, and their adsorption kinetics and adsorption isotherms were studied. The specific surface area and pore size of the three aged biochars were lower than those of fresh biochars. The increased number of oxygen-containing functional groups of the aged biochars would form a water cluster interaction with NOR, which was unfavorable to the adsorption of norfloxacin. The adsorption mechanism of biochar on NOR contains pore filling, electrostatic interaction, ion exchange and complexation. The adsorption of norfloxacin on biochar before and after aging was spontaneous and by quasi-second kinetics and the Langmuir equation. Different aging methods influenced the physicochemical properties and adsorption performance of biochar, and the adsorption capacity of biochar was significantly reduced after aging. Therefore, the influence of climatic factors needs to be considered when using biochar to remove target pollutants. This article is protected by copyright. All rights reserved.