Nkwocha Stephen Tochi is a National Science Foundation–funded Ph.D. candidate in Chemistry at the University of Wisconsin–Milwaukee, specialising in bioinorganic catalysis, EPR spectroscopy, and environmental remediation. He has authored multiple peer-reviewed articles, mentored award-winning student innovators, and served as a judge at the UWM Undergraduate Research Symposium. His awards include the Distinguished Dissertation Fellowship (UWM, 2025), the British Council International School Award, the EducationUSA Lagos Opportunity Funds Award, and the NIPES Outstanding Contribution to Research and Innovation Award.

He spoke about the conduct of examinations in Nigeria, the challenges and measures to address them. Tochi explained how his work focuses on water pollution and how it shapes public health. He advocated for a national flood-control master plan for Nigeria to tackle incidents of flooding.

What inspired your recent post on free virtual tutorials for the Unified Tertiary Matriculation Examination (UTME) and the West African Senior School Certificate Examination (WASSCE) students?
The inspiration came from what I saw daily as a teacher. Many brilliant students were failing UTME and WASSCE not because they lacked ability, but because they lacked access to quality instruction. In 2020, during the pandemic lockdowns, I launched the One Month Chemistry free virtual tutorial series. Using WhatsApp, Telegram, and YouTube, I offered structured lessons on Chemistry topics—acid-base equilibria, organic chemistry, atomic theory—simplified for secondary students. Over time, this grew into a network reaching more than 1,500 students across Lagos, Ogun, and beyond. Parents sent feedback of children moving from borderline grades to distinctions. For me, this confirmed that access to education is a social equalizer.

How easy is it to teach students virtually, and what has been their response so far?
It is not easy at all, especially when you have to hold the attention of a 16-year-old on a phone screen. But I built interactive methods. I created quizzes with instant feedback, encouraged peer discussion groups, and used real-life applications to explain abstract Chemistry principles. For example, when teaching chemical equilibrium, I used Nigeria’s fuel subsidy debate as a metaphor. The students loved it. The response has been overwhelming: I’ve had parents calling me to say their children “finally enjoy chemistry.” Several of these students are now undergraduates in science and engineering, which proves that virtual learning, if well-designed, can be effective in Nigeria.

What more can be done to make Mathematics and Science subjects attractive to secondary school students, especially boys?
First, we must change the narrative that science is “too difficult.” Science should be taught as a problem-solving tool, not just as abstract formulas. When I led the Science and Innovation unit at Dansol High School, we built robots, drones, and water filtration prototypes. Boys in particular engaged more when they saw that science could be “hands-on” and linked to technology. Secondly, mentorship matters. When boys see young Nigerian scientists winning awards globally, they realise it’s possible. Finally, we need national competitions, scholarships, and internships in STEM fields, these create healthy competition and motivate students to stick with challenging subjects.

This year alone, both the Joint Admissions Matriculation Board (JAMB) and the West African Examinations Council (WAEC) recorded serious glitches, leading to resits, re-marking, and upgrading of marks. How would you assess the situation, and what steps do you suggest to make the process seamless?
The situation is concerning because it affects students’ confidence in the system. JAMB and WAEC are high-stakes exams; even small errors disrupt lives. The glitches point to inadequate IT infrastructure and poor stress-testing of exam platforms. To address this, we need: One, pre-exam simulations where the system is tested at scale under peak loads. Two, independent oversight committees involving both IT experts and educators, and three, investment in robust data servers, not just rented infrastructure.

We must also establish transparent redress mechanisms so students trust that errors will be corrected fairly. If we fail to fix this, we risk discouraging thousands of young Nigerians from pursuing higher education.

Your work and research in the U.S. focus on water and water pollution. Why did you choose this area?
Because water is life—and in Nigeria, water is also a silent killer. My MSc research at the University of Lagos looked at detoxifying polluted water using activated carbon from agricultural waste. Later, I expanded into studying heavy metal contamination in Lagos wetlands. These experiences opened my eyes to how deeply water pollution shapes public health. When I came to the U.S. for my PhD, I decided to focus on water at the molecular level—specifically, how nitrate pollutants can be broken down by natural enzymes. My choice wasn’t abstract—it was rooted in real communities in Lagos, and it continues to inform how I design global solutions.

What are the major water-related challenges facing Nigeria today?
They fall into three categories: One, chemical pollution – heavy metals, pesticides, and nitrates entering our water systems unchecked. Two, infrastructure deficit – only about 10% of Nigerians have access to safely managed drinking water. Three, flooding and climate stress – Uncontrolled urbanisation and poor drainage make periodic floods devastating.

These challenges overlap—polluted floodwater seeps into wells and farmlands, compounding the crisis.

What solutions would you recommend, and are there technological innovations that could be deployed to tackle these challenges?
Yes, several. On a small scale, low-cost activated carbon filters using waste biomass can be deployed in rural households—my MSc research demonstrated this. On a larger scale, electrochemical sensors can provide real-time water quality monitoring; I have designed prototypes during my doctoral work. Finally, enzyme-inspired catalysts for nitrate reduction, based on my NSF-funded PhD research, could transform industrial wastewater treatment. Nigeria needs a layered approach: community-level innovation for households and state-level infrastructure for urban water systems.

Flooding in Nigeria is both an environmental and governance challenge. In Adamawa and Zamfara, for example, rivers like the Benue and Rima routinely overflow during heavy rains, destroying homes, farmland, and infrastructure. To prevent these recurring disasters, we need a multi-layered strategy: One, urban and regional planning enforcement. A major cause of flood devastation is uncontrolled construction on natural waterways and floodplains. Government must strictly enforce zoning laws and relocate settlements away from high-risk areas. In cities like Yola and Gusau, drainage channels are often blocked by illegal structures—this is avoidable with proactive planning.

Two, Nigeria needs a national flood-control master plan, modeled on what countries like the Netherlands have done. This includes: Levees and embankments along vulnerable rivers, retention basins and reservoirs to absorb excess water during peak rains, and dredging of rivers like the Benue to increase their water-carrying capacity.

Some of these can be developed through public–private partnerships (PPP) with construction firms that build and maintain the systems under concession agreements.

Three, early warning systems and community preparedness. Technology can save lives. Simple SMS-based flood alerts, like those used in Bangladesh, can give communities 48–72 hours to prepare. Schools, markets, and community centers should double as emergency shelters during floods. In Adamawa, where floodwaters often displace thousands, this kind of preparedness can drastically reduce casualties.

Four, climate-resilient agriculture. Most flooding impacts farmers first. By supporting farmers with raised-bed farming, improved drainage, and crop insurance schemes, the government can protect livelihoods. Insurance, in particular, is a neglected tool—PPP models can make it affordable, ensuring farmers recover faster after floods.

The next one is watershed management and reforestation. Deforestation in northern states increases runoff, making floods worse. Large-scale tree planting and watershed management can stabilize soil, slow runoff, and reduce flood peaks. Community-based forest management should be incentivized with grants and job creation schemes.

Finally, regional collaboration. Rivers like the Benue are international waterways, fed partly by Cameroon. Nigeria must strengthen cross-border water management agreements to regulate upstream dam releases, which often worsen downstream flooding in Adamawa.

In short, preventing floods in Adamawa, Zamfara, and elsewhere requires infrastructure investment, strict planning enforcement, community resilience, and regional cooperation. The science is clear: floods will intensify with climate change. The question is whether Nigeria is prepared to manage them proactively or continue reacting to disasters after they strike.

In what ways can Nigeria better manage its water resources to generate more income?
Nigeria is blessed with abundant rivers, wetlands, and rainfall, yet we underutilise these resources. Properly managed, water can become a driver of national income. Let me highlight five areas: One, hydropower and mini-grids. Nigeria currently generates only a fraction of its hydropower potential. Beyond large dams like Kainji, smaller hydro facilities can power communities and industries, reducing reliance on diesel generators. This saves foreign exchange and creates jobs in engineering, maintenance, and operations. Two, agricultural irrigation. Much of our agriculture still depends on unpredictable rainfall. With modern irrigation powered by treated water from rivers and recycled wastewater, we can boost dry-season farming.

This reduces food imports and generates export income. Countries like Israel have built billion-dollar agricultural exports on efficient water use—we can do the same. Three, industrial partnerships (PPP Models).

This is where private sector involvement is critical. Industries consume enormous amounts of water—for cooling, washing, and production. With government regulations and incentives, private companies can invest in water treatment and recycling plants that not only serve their factories but also provide treated water to nearby communities. In Lagos, for example, beverage and bottling companies could partner with state water boards to build joint water purification systems, reducing pressure on public utilities.

The next one is eco-tourism and recreational use. Clean water bodies attract tourism. Imagine the economic value of well-managed rivers in places like Lokoja, where the Niger and Benue meet, or the Osun-Osogbo sacred grove if the river running through it were pollution-free. Eco-tourism linked to clean rivers can create thousands of jobs in hospitality and local transport. Finally, export of processed water and technology.

Nigeria can lead in developing low-cost purification technologies—such as the biomass-activated carbon I worked on during my MSc. These systems can be manufactured locally and exported to other African nations, positioning Nigeria as a regional hub for water treatment technology.

The truth is, water is not just a survival need—it is an economic asset. If we manage it with innovation, regulation, and partnerships, water can contribute significantly to our GDP while ensuring Nigerians enjoy safe, clean access to this essential resource.

What innovations are needed to manage water pollution and wastewater effectively?
We need affordable, decentralized technologies. Imagine a local government having portable water-testing kits connected to cloud servers for real-time reporting. That’s entirely possible. In addition, constructed wetlands—engineered natural systems—can treat wastewater cheaply. Finally, bioremediation using bacteria and enzymes, like the one I study, can transform harmful nitrates into harmless products. These are not futuristic—they exist today, and Nigeria must adopt them.

Recycling of water is not common in Nigeria. What is your view on this?
Recycling is essential. In California, treated wastewater already supplements drinking water. In Nigeria, we waste so much potential—factories discharge water that, if treated, could irrigate farmland. Recycling also reduces pressure on groundwater aquifers, which are drying up in parts of northern Nigeria. Yes, the “psychological barrier” exists—people resist drinking recycled water—but with education and transparency, Nigerians can embrace it.

What problem does your research aim to solve both in Nigeria and globally?
My PhD research is titled: “Mechanistic Studies of Cytochrome c Nitrite Reductase: Implications for Nitrate Remediation in the Nitrogen Cycle.” The problem it solves is nitrate contamination—a global issue. In Wisconsin, it leaches from farmland into drinking water; in Nigeria, it comes from fertilizer runoffs into rivers. By understanding how nature’s enzymes detoxify nitrate, we can design sustainable, low-cost remediation systems for communities everywhere. It’s a project rooted in science, but its heartbeat is human—ensuring every family can drink safe water.