Water hyacinth is one of Kenya’s most troublesome invasive plants, clogging lakes and rivers across the country. However, MMU researcher Prof. Anastasiah Ngigi’s research is giving the aquatic weed a new purpose, creating eco-friendly biochar composites that can sorb antibiotic residues and antibiotic resistance genes in manure before it is applied to farmland.
“Manure contains traces of antibiotics given to animals. These drugs can cause bacteria to become resistant, making infections harder to treat in both animals and people,” Prof. Ngigi explained.
When manure with antibiotics is spread on farms, it can transmit these resistant bacteria and genes into the soil, water, and food chains.
Serious health and environmental risks posed by these antibiotics is what motivated Prof. Ngigi to carry out the research and she eventually won the prestigious Alexander von Humboldt (AvH) Fellowship to carry out what has been termed as impactful research in fight against antibiotic resistance in agriculture.
The 18-month project, based in Germany at Universität Trier hosted by Prof. Dr. Sören Thiele-Bruhn who is also a co-researcher, is focused on using water hyacinth to make biochar — a special charcoal-like material — infused with clay minerals into highly functionalized biochar composites-to treat animal manure.
“The goal is to reduce the spread of antibiotic resistance, a major public health threat, especially in developing countries, said Prof. Ngigi.
With agriculture being a cornerstone of Kenya’s economy, dual function of biochar composites to enhance soil fertility and mitigate health risks promises increased agricultural productivity, improved human health, and greater environmental protection.
Since the start of the fellowship in May 2025, Prof. Ngigi has commenced preparation and characterization of the biochar adsorbents, marking the first major milestone of the project.
By Faith Nashipai and Nicanor Ndiege