Lead, cadmium, and other heavy metals released from factories, mining activities, and untreated waste continue to contaminate rivers, lakes and groundwater. These pollutants threaten both ecosystems and human health. To address the problem, a Kenyan research team is developing innovative rinsing. Notably, since maize tassels which are an abundant and cheap resource are used as purification agents, the method will be affordable.
A research grant from KENET, the national research and education network (NREN) of Kenya, has enabled computational simulations, which are instrumental to the project.
Heavy metal pollution is often invisible, odorless and difficult to remove. A team led by Dr. Lucy Kiruri, Lecturer in the Department of Chemistry, Kenyatta University, seeks to use modified maize tassels to remove heavy metals from water through so-called bio-sorption.
Builds on high-performance computing
In 2019, Dr. Kiruri was awarded a grant under KENET’s Computational Modelling and Materials Science (CMMS) academic area. The grant facilitated the purchase of high-performance computers that were essential for running complex simulations and handling large datasets. These systems allowed the team to carry out local runs, including preparing input files before submitting jobs for computation. After the simulations were completed, the same machines were used to analyse output files and study molecular trajectories in detail.
“Since I completed my PhD in the US in 2014, this grant opened my research journey. I have published 15 papers, which I largely attribute to the support from KENET in acquiring the computers that my students use to date. The grant also opened doors for collaboration with other researchers since funding attracts partnerships and new opportunities,” says Lucy Kiruri.
Dr. Kiruri undertook the project in collaboration with Dr. Isaac Mwangi, Lecturer in the Department of Educational Communication & Technology, Kenyatta University, and Dr. Joanne Ogunah, Lecturer in the Department of Physical Sciences, University of Embu.
Enhancing surface chemistry
The innovative solution is rooted in the idea that natural and readily available materials can be transformed into effective purification agents when their surface chemistry is enhanced. To improve performance, the maize tassels were treated with ethylenediamine, a compound known to strengthen the ability of materials to bind positively charged metal ions. This treatment increased the number of active sites on the tassels, allowing them to better capture and hold metals such as lead, cadmium, and copper from polluted water.
Further, the team used Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations to examine how heavy metals interact with the modified maize tassel material at both atomic and molecular levels.
Beyond its scientific value, the study also demonstrated that this method offers environmental and socio-economic benefits. It showed that widely available agricultural waste can be effectively used as a sustainable alternative to expensive water treatment methods such as activated carbon systems, membrane filtration, and chemical precipitation.
Source: The article “Low-Cost Solution to Heavy Metal Pollution Found in Maize Fields” at the KENET website.
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