Reusing Wastewater in Agriculture Inspires Cum Laude Master’s Graduate

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Buoyed by a commitment to food security and environmental preservation, Mr Barnabas Oluoch’s Master’s in Crop Science dissertation explored sustainable agriculture and the use of advanced oxidation processes to remove pathogens from wastewater for safe crop irrigation.

Originally from Kenya, where he grew up on the shores of Lake Victoria, Oluoch completed his undergraduate and honours degrees in environmental sciences at the University of Eldoret, specialising in environmental biology and health, graduating with second-class honours.

His passion for sustainability, particularly in wastewater treatment, resource recovery and agriculture, drew him to UKZN to study under Professor Alfred Odindo and Professor Stephen Ojwach. Attracted by the University’s research excellence and innovative environment, Oluoch found strong mentorship, state-of-the-art facilities and a collaborative academic culture.

He sought to work at the nexus of agriculture and environmental health to contribute to crop systems that produce nutritious food, conserve resources, recycle waste and reduce pollution.

Oluoch’s research used ozone- and ultraviolet (UV)-based treatments to remove pathogens from wastewater for irrigation - critical in water-scarce regions - and supported waste reduction, sustainable water management, reduced freshwater dependence and global efforts toward a circular agricultural economy, aligning with at least three United Nations Sustainable Development Goals.

He found that specific advanced oxidation processes effectively eliminated pathogens and improved the physicochemical properties of treated wastewater. Ozonolysis, for instance, met pathogen standards set by international bodies and increased nitrate and ortho-phosphate levels, which are beneficial for fertigation.

However, UV+Titanium - a photocatalyst - proved toxic to crop growth and consumers of crops such as Swiss chard and lettuce irrigated with treated effluent, posing health risks such as in the liver and spleen, heart injury, colon cancer, allergic reactions, gastrointestinal issues and placental dysfunction.

His strong academic performance led to three peer-reviewed publications in Heliyon, Environmental Science and Health, and Hazardous Materials. Adapting to a new academic environment in a different country had its challenges, but being goal-oriented, relying on peer support and maintaining communication with his supervisors helped him persevere.

He balanced his studies with church activities and music production, managing his time through structured schedules and clear goals while prioritising rest, reflection and spiritual grounding.

Now pursuing a PhD at UKZN, Oluoch is expanding his focus to contaminants of emerging concern (CECs) in wastewater, such as pharmaceuticals, which affect crops and soil. He is working on methods to remove these and hopes to contribute to academia and sustainable agricultural development.

Oluoch thanked his family for their unwavering support, Professor Odindo and Professor Ojwach for his mentorship, UKZN friends and peers for enriching his experience, the Water Research Commission of South Africa for funding, and God for the strength and wisdom to pursue his passion.

Words: Christine Cuénod

Photographs: Sethu Dlamini and supplied