Habib Isa Adamu

Kaduna State University, Nigeria

Green Synthesis and Characterization of Iron Oxide Nanoparticles from Rice Husk and Orange Peel Extract and Residue Template (RHOPTNPs) for the Adsorptive Removal of Ciprofloxacin and Ibuprofen from Aqueous Solution

Biography

Dr. Habib Isa Adamu is a Lecturer I in the Department of Pure and Applied Chemistry at Kaduna State University, Nigeria, where he has served since 2017. He holds a PhD and MSc in Environmental Chemistry from the Nigerian Defence Academy and a BSc in Chemistry from Ahmadu Bello University, Zaria. He is currently pursuing an MBA in Human Resources and an MSc in Sustainable Environmental Studies at Ahmadu Bello University. His research interests focus on environmental chemistry, nanotechnology, adsorption, water pollution, heavy-metal contamination, and sustainable environmental remediation. His research has resulted in publications on green-synthesized iron oxide nanoparticles, heavy metals, adsorption of emerging contaminants, pesticide residues, and sustainable remediation technologies. Beyond academia, Dr. Adamu has extensive experience in environmental consultancy, project management, environmental field studies, waste management, and stakeholder engagement. He has worked with the Japan International Cooperation Agency (JICA) and Green Habitat Initiative and is a member of the Institute of Chartered Chemists of Nigeria and the Chemical Society of Nigeria.

Abstract

Pharmaceutical contamination of water bodies by antibiotics and anti-inflammatory drugs poses a growing environmental and public health concern, driving interest in low-cost, green-synthesized adsorbents. In this study, iron oxide nanoparticles were synthesized via a green co-precipitation route using a combined extract and residue (template) of rice husk and orange peel, designated RHOPTNPs, and evaluated for the removal of ciprofloxacin and ibuprofen from aqueous solution. Fourier Transform Infrared Spectroscopy confirmed the presence of phenolic and hydroxyl functional groups responsible for nanoparticle capping, while UV-Vis spectroscopy showed a characteristic absorption peak at 305 nm. Dynamic Light Scattering revealed an average particle size of 76.24 nm with a polydispersity index of 0.411, and Scanning Electron Microscopy–Energy Dispersive X-ray spectroscopy confirmed a Fe–O–C elemental composition (77.85, 20.02, and 3.22 wt%, respectively). X-ray diffraction confirmed a cubic magnetite crystal structure, and Brunauer–Emmett–Teller analysis showed a surface area of 846.28 m²/g and pore volume of 0.658 cm³/g, the highest among the nanoparticle types studied. Batch adsorption experiments showed a maximum ciprofloxacin removal efficiency of 99.45% at an optimum dose of 80 mg, 40 minutes contact time, pH 7, and 320 K, while ibuprofen removal reached up to 94.40% under optimized conditions. Equilibrium and kinetic data fitted well to the Freundlich isotherm and pseudo-second-order kinetic models (R² = 0.98642 for ciprofloxacin), indicating a heterogeneous, chemisorption-driven adsorption mechanism. Thermodynamic analysis indicated a spontaneous, exothermic process. These findings position RHOPTNPs as an effective, sustainable adsorbent for pharmaceutical removal from contaminated water.