Banana peel biochar from pyrolysis for the removal of nitrofurantoin in wastewater

The antibiotic nitrofurantoin is widely used in the treatment of urinary tract infections. Despite its therapeutic benefits, the presence of nitrofurantoin in the environment poses significant ecological risks due to its ecotoxicity and mutagenicity. To mitigate these impacts, biochars produced from biomass via pyrolysis have emerged as promising adsorbents for the removal of contaminants from wastewater. This study evaluates the adsorption efficiency of banana peel–derived biochar for removing nitrofurantoin from aqueous solutions. The biochar was characterized using scanning electron microscopy, revealing a well-developed porous structure; energy dispersive spectroscopy, showing a high carbon content; and Fourier-transform infrared spectroscopy, identifying functional groups such as hydroxyls and carbonyls, and the specific surface area was calculated using the Brunauer–Emmett–Teller method, resulting in 1.5 m² g⁻¹. The adsorption study indicated a removal rate of 98% in 60 min. The maximum adsorption capacity, determined by the Langmuir model, was 3.78 mg g⁻¹, and the pseudo-second-order kinetic model indicated that chemisorption is the predominant mechanism of adsorption. Therefore, banana peel–derived biochar demonstrated effective potential for the removal of nitrofurantoin from wastewater.