Green Synthesis and Characterisation of Iron Oxide Nanoparticles Using Rice Husk and Orange Peel Extracts and Residue Templates (RHOPTNPs) for the Adsorptive Removal of Ciprofloxacin and Ibuprofen from Aqueous Solution
Year: 2026
Type: preprint
Abstract: Pharmaceutical contamination of water bodies by antibiotics and anti-inflammatory drugs poses a growing environmental and public health concern, while, driving interest in low-cost, green-synthesized adsorbents. In this study, iron oxide (Fe₃O₄/Fe₂O₃) nanoparticles were synthesized via a green co-precipitation route using a combined extract and residue (template) of rice husk and orange peel, designated as RHOPTNPs, and evaluated for the removal of ciprofloxacin and ibuprofen from aqueous solution. Spectroscopic and microscopic characterization confirmed the formation of capped, cubic magnetite (Fe₃O₄) nanoparticles with a BET surface area of 846.28 m² g⁻¹ and a pore volume of 0.6582 cm³ g⁻¹. Batch adsorption experiments showed a maximum ciprofloxacin removal efficiency of 99.45% under optimized conditions that include; a dose of 80 mg, 40-minute contact time, pH 7, and a temperature of 320 K, while ibuprofen removal reached up to 92.21% under the same optimized conditions. Equilibrium and kinetic data fitted well to the Langmuir isotherm and pseudo-second-order kinetic models, thus, indicating a monolayer, chemisorption-driven adsorption. Thermodynamic analysis showed a spontaneous process that was endothermic and exothermic for ciprofloxacin and ibuprofen, respectively. RHOPTNPs retained good performance over repeated adsorption–desorption cycles and were effective in treating real hospital and domestic wastewater, hence, establishing their potential as a sustainable, low-cost adsorbent for pharmaceutical contaminants present in water.
Source: Research Square
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7220734530