Process analysis of aqueous ciprofloxacin adsorption by biochar–magnetite nanocomposites

The widespread presence of antibiotics like ciprofloxacin in hospital wastewater poses serious environmental and health risks due to antibiotic resistance. This study presents the synthesis and application of a magnetically separable biochar–magnetite nano-composites for efficient adsorptive removal of ciprofloxacin. Biochar based adsorbents are sustainable, environmentally friendly, low cost and scalable with tuneable surface chemistry and regeneration capacity. In this study, orange peel biochar (CB) was doped with magnetite (Fe3O4) to prepare three different magnetic biochar-magnetite nano-composites CBC-2, CBC-5, CBC-10 which were examined for maximum removal efficiency of ciprofloxacin which is a popular broad-spectrum synthetic fluoroquinolone antibiotic. It is poorly metabolized, frequently excreted from body in unmetabolized and hence reported as a major pollutant in hospital waste water. The best adsorption efficiency was found at pH 8.0 and 298 K temperature by CBC-10 composite with the highest adsorption capacity (~ 90%), 1.25 gm.L−1 adsorbent dose, and the fastest equilibrium rate (60 min contact time) for the lowest ciprofloxacin concentration of 30 ppm. These results suggested that the biochar magnetite composites can serve as a promising adsorbent for the removal of antibiotic traces in the hospital and pharma industry effluents.