Problem Statement
There has been a surge in plastic waste generation since the COVID-19 pandemic, posing a threat to marine life, human health, and the environment. This project aims to determine the distribution and composition of microplastic waste in Kenya, as well as design low-cost carbon reactors from it.
Progress Highlights
The University of Nairobi has developed its research infrastructure by purchasing laboratory equipment, including a two-stage chemical vapor reactor, a UV-visible spectrophotometer, and a thermal gravimetric analyzer, among others. We are building human capacity by training two undergraduate students, two masters’ students, and two doctorate students.
Key Findings
Porous carbons with high adsorption capability for the removal of organic contaminants in waste water were produced from polyethylene terephthalate plastic waste. Multiwalled carbon nanotubes have been effectively produced from polypropylene terephthalate waste and polypropylene waste collected from the Dandora dumping site in Kenya.
Potential Impact
The effective synthesis of porous carbons and multiwalled carbon nanotubes from plastic waste offers a less expensive and more ecological alternative for repurposing of plastic waste. The adsorption characteristics of porous carbons for the elimination of organic contaminants in water may help achieve clean water and sanitation.
Summary
Plastic pollution continues to steadily rise in most African countries causing major negative impacts on health, environment, and economic development of these countries. The plastics readily degrade into microplastics and nanoplastics which can be ingested by marine organisms, transferred to the soil and ultimately to the human body causing far-reaching health issues. Dr. Mutuma’s project will focus on the conversion of plastic waste into low-cost carbon reactors which can then be coupled with metal oxides, products that can be used to degrade nanoplastics from wastewater aided by light (photocatalysis). These products will also be used to detect toxic compounds in air that are associated with lung diseases and increased mortality rates. The application of plastic waste-derived nanomaterials for waste treatment and detection of toxic compounds is economical and provides a solution for sustainable environmental management, health, and wellbeing. The success of this project will provide a solution for reducing plastic pollution whilst providing affordable carbon-based products and devices.
Grantee Description
Dr. Bridget Mutuma is a Research Associate in the Department of Chemistry, University of Nairobi. She is also an AAS affiliate (Cohort 6) as well as a fellow of the Africa Science Leadership Programme. She has a BSc. degree in Analytical Chemistry from Kenyatta University, (Kenya, 2009), an MSc degree in Material Science and Engineering from Kangwon National University (South Korea, 2013) and a PhD in Chemistry (Nanomaterials) from the University of Witwatersrand (South Africa, 2016). Dr. Mutuma has extensive postdoctoral experience in nanomaterials, sensor technology and energy storage systems. Her research interest is in the development of plastic waste-derived carbon nanomaterials/core-shell nanostructures for use in gas sensors, solar cells, supercapacitors and photocatalysis.
Dr Mutuma aspires to be a leading scientist in the area of sensor technology, photocatalysis and solar energy conversion as she seeks to provide solutions for mitigating plastic and air pollution through innovation and infrastructure development in Africa.
Project: From plastic waste to low-cost carbon nanoreactors for use in monitoring environmental pollutants and nanoplastics
The nanoplastics project aims to assess the distribution of microplastics and nanoplastics from selected cities and coastal ecosystems in Kenya. The plastics and microplastics from the selected areas will be converted into low-cost carbon nanomaterials using environmentally friendly routes. The utilization of plastic waste is an economical way of waste recycling whilst producing value-added materials for sustainable consumption of materials. The use of these carbon nanomaterials (nanoreactors) as catalysts will be applied in the degradation of organic pollutants and nanoplastics providing a platform for decreasing plastic pollution in the cities. The applied holistic strategy will create job opportunities as well as human capacity building through nanotechnology training of postgraduate students. The nanomaterials generated will also be applied in the sensor technology to detect pollutants in the air thus addressing key global environmental challenges. The project will contribute to the transformation of Africa into a knowledge-based and innovation-led continent.
