Low cost iron modified syzygium cumini l. Wood biochar for adsorptive removal of ciprofloxacin and doxycycline antibiotics from aqueous solution

Antibiotic traces in household and industrial effluents have a harmful influence on the ecosystem as well as on human health. Antibiotic resistance in microorganisms arises because of inadequate antibiotic removal by conventional treatment processes. This study investigatesthe sorption of ciprofloxacin (CF) and doxycycline (DC) antibiotics, from an aqueousenvironment by modified wood biochar of commonly found tree species Syzygium cumini L. The elemental, porosity and functional group involvement have been studied using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Fourier Transform Infrared (FTIR) and Brunauer-Emmett-Teller (BET) analysis. The BET surface area was found to be 16.93 m² g⁻¹, pore volume and pore sizes were 0.018 cm³ g⁻¹ and 42.30 Å, respectively. The maximum percent of removal of antibiotics was found to be 96.23% and 96.90% for doxycycline and ciprofloxacin, respectively. The equilibrium data weretested for fit using Langmuir and Freundlich models. Inboth cases, the Langmuir model suited the data wellwitha maximum adsorption capacity of 4.32 and 4.25 mg g⁻¹ for doxycycline and ciprofloxacin, respectively. The data indicated the spontaneous and exothermic behavior of adsorption.Regeneration of the spent adsorbent up to ten cycles of continuous sorption followed by desorption showeda small decrease in sorption up to 3.55% for DC and 2.85% for CF. The biochar could be usedas an adsorbent for treating pharmaceutical effluents as well as municipal sewage wastewater.