Waste Valorization to Nanomaterials Classification, Synthesis Methods, and Applications

1. General introduction   2. Impact of waste valorisation on the circular economy  3. Recovery of rare earth elements and platinum group metals  4.  Classification of nanomaterials derived from waste  5. Synthesis of nanomaterials  6. Industrial-upscale synthesis of waste-derived nanomaterials  7.Preconcentration of potentially toxic metals and organics  8.Electrochemical sensor for metals and trace organics   9.Chemical sensors for metals and trace organics  10. Remediation of Trace Metals and Organics using Nanomaterials derived from Waste   11.Application of waste-derived nanomaterials in food, pharmaceutical, and cosmetic industries  12.Toxic effects of nanomaterials on the environment and health

Biography

Anele Mpupa obtained his Bachelor of Science (Chemistry and Microbiology) and BSc (Hons) in Chemistry from Rhodes University. Later, he completed his MSc and PhD in Chemistry from the University of Johannesburg. He has received funding from the National Research Foundation (NRF) from 2017 – 2020 for his MSc and PhD respectively, he was also a recipient of the highly competitive Deutscher Akademischer Austauschdienst (DAAD) German academic exchange service for a 4-month short stay research grant in Ulm University. He then served a post-doctoral research fellow at the University of Johannesburg under the Department of Science, Technology and Innovation-National Research Foundation South African Research Chair Initiative (DSTI-NRF SARChI) in Nanotechnology for Water. His research is centred around water research, which includes water quality monitoring and the analysis of chemical and biological pollutants in water. Furthermore, Dr Mpupa focuses on the development of methodologies based on chromatography and spectroscopic detection of water pollutants. Additionally, Dr Mpupa’s research also adds an element of material science by preparing different materials for use as sorbents, these include metal oxides, nanomaterial composites and functional materials such as molecularly imprinted polymers for the extraction and removal of pollutants. Therefore, the research focus on the development of adsorbent materials for the determination of emerging pollutants in water matrices. Furthermore, some of the developed materials are tested for their potential for the mitigation of pollutants in water, with special attention being paid to efforts on using recyclable feedstocks.

 Shirley Kholofelo Selahle is an emerging researcher who graduated with a Doctor of Philosophy degree in Chemistry from the University of Johannesburg. After obtaining her PhD degree, she started her post-doctoral research fellowship at the University of Johannesburg. She joined the University of Venda later in 2023 as a lecturer in Analytical Chemistry. Dr Selahle’s arrival at the University of Venda saw her establish an Analytical Environmental Chemistry Research Laboratory/Group that is growing yearly. This group is currently composed of 4 Msc students, 1 PhD student and 3 honors students under her supervision. This research group focuses on the development of sample preparation methods for the analysis and removal of emerging pollutants in water matrices using nanomaterials. Emerging pollutants are chemical substances that fall out of standard monitoring and regulatory programs. These chemicals occur at low concentration levels, which makes their monitoring a challenge. Therefore, her research focus also expands to the development of adsorbent materials for the determination and quantification of emerging pollutants in environmental water matrices. Taking into consideration Green Chemistry, her research also involves the use of waste materials to make composites that are friendly to the environment, and to utilise them for water treatment. The materials are designed in such a way that they result in a high percentage of recoveries of the targeted pollutants and improve the detection limits of the analytical instruments used for analysis. During her academic journey, she has received several funds, including the Global Excellence Stature (GES) fellowship and the National Research Foundation, in support of her postdoctoral fellowship. She is currently an emerging researcher who is funded by the THUTHUKA grant from the National Research Foundation. She has contributed to the body of knowledge through research publications in reputable journals and presentations at local and international conferences. He also serves as a reviewer in international Journals such as MDPI and Frontiers in Chemistry, among others. In 2024, she was recognised as one of the young 200 South Africans making a positive impact in the country by the Mail and Guardian.

 Philiswa Nosizo Nomngongo is a full Professor of Environmental Analytical Chemistry at the University of Johannesburg, Faculty of Science (Department of Chemical Sciences). She holds a DSI-NRF SARChI in Nanotechnology for Water. Her scientific career has been dedicated to Environmental Analytical Chemistry and Nanotechnology, aiming to solve environmental problems in water quality and environmental protection. Her most significant contributions have been mainly in developing sample preparation methodologies using nanostructured materials as adsorbents for monitoring inorganic (toxic trace metals and metalloids) and organic pollutants (more specifically, emerging contaminants which include pesticides, endocrine disruptors and personal care and pharmaceutical products) in water systems. Her current research includes the application of various nanomaterials in fields that are attracting increasing interest, such as wastewater treatment, groundwater remediation, water quality monitoring, development of water quality sensors, and treatment and recovery of precious metals, among others. Her research achievements have recognised through numerous awards such as the L'Oreal-UNESCO Sub-Saharan Women in Science Regional fellowship in 2014, the South African Women in Science award in the Distinguished Young Woman Research in the Natural and Engineering Sciences category in 2017, and Vice-Chancellor's Distinguished Award: Most Promising Young Researcher of the Year in 2017. Her other recognition includes African Academy of Science Affiliate, Southern African Women in Leadership Trailblazers Award winner (Top 10), 2020/2021 NSTF-South23 Award winner of Engineering Research Capacity Development category; NSTF-South23 Award Finalist (Categories: 2019/2020 TW Kambule: Emerging Researcher &Engineering Research Capacity Development; 2020/2021 TW Kambule: Researcher), 2025 James J. Morgan Early Career Award (American Chemical Society), among others. During her academic years at the University of Johannesburg (2015-present), Prof Nomngongo has supervised/ co-supervised 48 MSc and 32 PhD students. She is currently the supervisor/co-supervisor to several MSc and PhD students. She is the author/co-author of over 170 peer-reviewed publications, 28 book chapters, and two peer-reviewed conference proceedings. She has presented 50+ keynotes and invited contributions at scientific conferences. Her Google Scholar, Scopus and Web of Science H indices are 43, 37 and 34, respectively. Her work has been cited 5781 (Google Scholar), 4521 (Scopus), and 3832 (Web of Science) times. She is the Associate Editor of leading and prestigious international journals and publishing houses. She is also Topic editor for ACS Environmental Science & Technology Letters. She serves as an Editorial Board member of Discover Applied Sciences, Energy & Environmental Materials, ACS Environmental Science & Technology and Environmental Toxicology and Chemistry. She served as the Guest Editor for some international journals that are DHET accredited, including Frontiers in Chemistry, Frontiers in Environmental Science, Molecules and Materials

 Mthokozisi Mnguni was born and lived in various parts of KwaZulu-Natal. This phenomenon resulted in him studying in more than five primary schools. He completed his Matric in 2010 at Adams College based in Durban. Mthokozisi Mnguni completed his BSc in Chemistry and Chemical Technology (2014), Honors in Chemistry (2015), MSc in Chemistry (2017), and PhD in Chemistry (2022) at the University of KwaZulu Natal. The National Research Foundation (NRF) funded all the degrees besides BSc. Throughout his MSc research project, he acquired expertise in organic synthesis and studied the mechanisms and kinetics of biological reactions. In his PhD project, Mthokozisi Mnguni obtained expertise in designing nanomaterials with specialized morphologies for sample preparation of emerging contaminants from water. The knowledge obtained here enabled the appointment as a Postdoctoral research fellow in September 2023 at the University of Johannesburg under Prof Nomngongo, a DSI-NRF SARChI in Nanotechnology for Water. The following year (2024), Mthokozisi Mnguni obtained NRF Postdoctoral research funding for two years to research the fabrication of nanomaterials for extraction and removal of organic and inorganic contaminants from water. Mthokozisi Mnguni has co-supervised two MSc students to completion and is currently co-supervising one Honors, two MSc, and five PhD students. The current work has published four research articles and one book chapter. Mthokozisi Mnguni has presented his research at six local and international conferences

 Ngwako Joseas Waleng is an Assistant Lecturer and Postdoctoral Researcher in the Department of Chemical Sciences at the University of Johannesburg, South Africa. He specializes in analytical chemistry, with expertise in developing and applying advanced nanomaterials for wastewater remediation. He earned his PhD in Analytical Chemistry from the University of Johannesburg, where his research focused on developing sample preparation methods for the preconcentration and removal of pharmaceuticals from the environment. His research interests include environmental monitoring, wastewater remediation, nanomaterials for pollutant removal, chromatography, and chemometrics. His work integrates green chemistry principles, functional nanomaterials, and data-driven approaches to address pressing challenges in pollution control, water quality management, and sustainable development. He has authored and co-authored 10 peer-reviewed publications, contributing to the advancement of knowledge in analytical and environmental chemistry. He has also presented his research at both local and international platforms, engaging multidisciplinary audiences on innovative approaches to environmental remediation and analytical method development. Beyond research, He is actively involved in teaching and mentoring undergraduate and postgraduate students. He has experience in teaching courses such as general chemistry, instrumental analysis, and research methodology. His long-term goal is to bridge fundamental research in analytical chemistry with practical solutions for environmental and industrial challenges, thereby advancing both scientific innovation and societal impact.

 Siyabonga Shoba is a chemist and researcher with a passion for discovery and storytelling. He earned his master’s degree from Nelson Mandela University and holds a PhD in inorganic and analytical electrochemistry from the University of KwaZulu-Natal. He did a postdoctoral fellowship at Stellenbosch University under the mentorship of Prof. Wessel du Toit and Prof. Robert Pott, where he investigated oxygen mass transport in wine during nitrogen sparging and applied computational fluid dynamics (CFD). While also mentoring emerging researchers. Siyabonga is currently a postdoctoral fellow at the University of Johannesburg under the guidance of Prof. Philiswa Nomngongo. His research focuses on converting waste-derived materials into nanomaterials for the chemical modification of electrodes to detect and monitor heavy metals and emerging organic contaminants in water. also continuing to mentor the next generation of scientists.