Functionalized typha biochar for antibiotic removal via low-carbon integrated method: Performance and mechanism analyses

Abstract

Antibiotic residues in water represent an urgent environmental challenge. To efficiently remove these residues, a low-carbon integrated biochar synthesis method was proposed, and an optimized typha biochar (TBI_K) was prepared. Compared with the biochar prepared by a conventional two-step carbonization and activation method (TBT_K), the TBI_K preparation process reduced energy consumption by 43849.58 J and cut carbon dioxide emissions by 32.80%. TBI_K exhibited a large surface area of 1252.40 m²/g and rapidly achieved an equilibrium removal efficiency of 99.95% within 20 min for simulated antibiotics wastewater. Furthermore, TBI_K possessed more number of functional groups than TBT_K, especially O-H and C-S groups. The adsorption stability and tolerance of TBI_K in solutions with different ionic strengths and coexisting anions were examined. Characterization techniques such as scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), and X-ray photoelectron spectroscopy (XPS) as well as Brunauer, Emmett and Teller (BET) analyses were employed to elucidate the morphology and adsorption mechanism of the adsorbent. The microporous structure and abundance of functional groups are key to the excellent adsorption capabilities of TBI_K. Thus, this integrated method for biochar production, optimized for treating antibiotic wastewater, holds significant potential for future applications.