Agnes Pholosi

Title : Applications of core shell magnetic nanoparticles for the removal of emerging contaminants from water

Abstract:

Contamination of aquatic systems by antibiotics poses significant public and environmental health risks. Numerous approaches have been studied for the development of effective adsorbents for the removal of antibiotics from wastewater. In this study, magnetic core-shell nanocomposite was synthesized by coating magnetite with silica using the modified Stober route. The synthesized Fe₃O₄-SiO₂ surface was further polymerized with dopamine (DA) to obtain Fe₃O₄-SiO₂-PDA and cyclodextrin was then incorporated to obtain Fe₃O₄-SiO₂-PDA-CD. The morphology and elemental composition of the core-shell nanocomposite were characterized using SEM-EDX, TEM, XRD, XPS and FTIR techniques. Spherically shaped magnetite nanoparticles were obtained with a noticeable average particle increment on coating with silica as well as on incorporating polydopamine and cyclodextrin. Characterization techniques applied confirmed the magnetite coating with silica, polydopamine and cyclodextrin incorporation. The FTIR, XPS, and elemental analysis also confirmed the successful synthesis of Fe₃O₄-SiO₂, Fe₃O₄-SiO₂-PDA, and Fe₃O₄-SiO₂-PDA-CD due to the presence of the relevant and active functional groups in each adsorbent. Batch adsorption studies were conducted to investigate the effect of pH, adsorbent mass, contact time, and initial concentration on the ciprofloxacin (CIP) and tetracycline (TC) removal. Maximum adsorption capacity of 234.55 mg/g and 286.13 mg/g for the removal of CIP and 400 and 446.56 mg/g for the removal of TC from Fe₃O₄-SiO₂-PDA, and Fe₃O₄-SiO₂-PDA-CD, respectively. Pseudo-second order and Langmuir models best explained the kinetics and adsorption isotherm, respectively. The core shell magnetic nanocomposites can be applied as a reusable and cost-effective adsorbent for CIP and TC remediation.

Audience Take Away

• The audience will learn different techniques for the synthesis of core-shell magnetic nanocomposite and their modification for targeted pollutant.
• The audience can apply the technique for emerging pollutants remediation.
• A new material is development to mitigate associated health and environmental implications.
• This research work is the addition to the existing knowledge, it is the improved technology to address the pressing global environmental challenges.
• ​​​​​​​Other researcher could use this knowledge to expand their research.
• ​​​​​​​The synthesized adsorbent is cost effective and reusable demonstrating potential application in industries and water treatment plants which will contribute to clean environment and clean water for all.
• ​​​​​​​Development of a low-cost magnetic adsorbent that is easy to separate and effective for the removal of pharmaceuticals from the contaminated water.

Biography:

Dr Agnes Pholosi is a senior lecturer and a researcher at Vaal University of Technology, South Africa where she holds a portfolio of being the area leader for her research focus area (Adsorption and Environmental Research). She obtained her doctorate degree from the same University in 2019. Dr Pholosi’s research focus on the application of various materials for environmental remediation of emerging pollutants. She has shown potential as a research scientist in remediation chemistry by publishing 21 articles in peer reviewed journals and 2 book chapters. She effectively managed several postgraduates’ students’ projects and mentoring a Postdoctoral research fellow.