Removing antiretroviral drugs and heavy metals from wastewater using Cannabis sativa buds and Moringa oleifera leaves as bio-adsorbents was the focus of the research which earned Ms Thandeka Mbatha a cum laude Master’s degree in Chemistry.
Human health, aquatic life, and ecosystems are at risk because of the increasing contamination of water systems by pharmaceutical drugs and heavy metals that people do not completely metabolise, or that emanate from medical facilities, poor drug disposal or industrial activities. The persistence of these issues as well as solubility and resistance to degradation evades wastewater treatment plants.
With conventional removal methods including membrane filtration, reverse osmosis, or activated carbon effective but costly, energy-intensive and unsustainable, there is a need for alternatives.
Mbatha investigated innovative, plant-based solutions with medicinal benefits for cleaning contaminated water. For the first time, she tested Cannabis sativa buds and Moringa oleifera leaves as affordable bio-adsorbents, enhancing their ability to capture pollutants with simple, environmentally friendly modifications. She also applied a green extraction technique that uses minimal solvents to remove antiretroviral drugs efficiently.
Her findings demonstrate that bio-absorbents offer a sustainable, reusable, and eco-friendly solution for removing pharmaceutical residues and heavy metals from wastewater. This work contributes to global efforts toward clean water and sanitation Sustainable Development Goal (SDG 6) and improved health and well-being (SDG 3), highlighting the potential of plant-based technologies for cost-effective water quality management.
Originally from Nquthu in northern KwaZulu-Natal, Mbatha chose UKZN for her undergraduate, honours, and master’s studies due to its reputation for excellence in teaching and facilities, and its diversity. Its proximity to family also influenced her choice, and her experience of campus life did not disappoint.
Mbatha appreciated UKZN’s recognition of students who work hard and excel which was motivating.
Mbatha described the joy of being in the laboratory for the first time, having always envisioned contributing to solutions for water pollution, because of challenges with accessing safe, clean water where she grew up. Having researched possible careers at school, she found that chemistry helped her understand the world around her and provided applicable research to fields from medicine to food and agriculture.
During her studies, Mbatha achieved three Academic Merit certificates, a Dean’s Commendation award and was named the Top Second-year Female Student Achiever in Chemistry in 2021. She received a South African Chemical Institute second prize for a poster presentation during her honours and master’s years at UKZN and the University of Zululand, respectively, and presented at UKZN’s Postgraduate Research and Innovation Symposium in 2024.
Facing low self-esteem during her studies, Mbatha was assisted by Student Support Services to conquer negative thinking and involved herself in church activities and physical exercise to relax. Her faith in God provided considerable emotional stability and a sense of trust that comforted Mbatha, and helped in the completion of her studies.
Her supervisors, Professor Precious Mahlambi and Dr Sandisiwe Zondo, motivated her to achieve her potential and make them proud. Despite having to start some laboratory work afresh after months of work due to a minor error, her supervisors’ belief in her and a reminder of her purpose in pursuing these studies kept her going.
Mbatha remained true to her goal of becoming an analytical chemist to bring innovative change to water pollution and has enrolled for a PhD in Analytical Chemistry to tackle the concern of water inequality.
Mbatha thanked her mother and sister for their unconditional love and support, and her supervisors for their academic and research guidance. She acknowledged her friends and research group colleagues for their moral support and assistance, and the National Research Foundation for the funding it provided through her supervisors during her first year of master’s studies. She also thanked UKZN and the Discipline of Chemistry for the supportive environment they provided.
Words: Christine Cuénod
Photograph: Supplied