By Isaac Atunlute
For decades, chlorine has been the go-to disinfectant for drinking water in Nigeria and around the world. Its effectiveness and affordability make it a staple for public and private water-treatment facilities, with 99.8% of such facilities in Nigeria dependent on it.
However, this widespread adoption comes with significant hazards, prompting calls for safer alternatives.
Many Nigerians today, particularly in urban areas like Abuja, Lagos, and Port Harcourt, have complained about the pungent chemical aftertaste of their tapwater–an obvious proof of over-chlorination.
The health concerns go beyond just taste. Excessive use can promote gastrointestinal disease and cancer from ongoing contact with disinfection byproducts like trihalomethanes (THMs).
As the health risks and disadvantages of chlorine disinfection are increasingly being viewed as major concerns, safer and more ecologically friendly alternatives are being designed.
This highlights the innovations not only in regards to rating their actual performance in practice but also in regards to the potential for reshaping water purification in places like Nigeria, where access to pure water is important and directly related to health in general.
Offering a timely voice in global water purification discourse that is sustainable and equitable
More Promising Alternatives
Ozone: Nature’s Powerful Disinfectant
Ozone (O₃), a naturally occurring molecule, is 50% more potent than chlorine as an oxidizing agent against viruses and bacteria. Unlike chlorine, ozone leaves no chemical residue in water. It kills by perforating cell walls and instantly inactivating pathogens.
Efficacy: Ozone is more efficient in inactivating E. coli and Cryptosporidium compared with chlorine, according to research providing faster and more comprehensive disinfection and no toxic residues from chemicals.
Limitation: Ozone is not permanent and must be created on-site and is more costly for small or rural systems.
UV Radiation: Purifying Light
Ultraviolet (UV) disinfection is a chemical-free technology that kills microorganisms’ DNA through use of UV-C light. It is being widely applied in hospitals, cities, and households.
Effectiveness: According to studies, UV can eliminate 99.99% of bacteria and viruses.
Benefit: No taste or odour alteration, no residual byproducts.
Drawback: Requires clear water and an uninterrupted supply of electricity, which may be a challenge in certain parts of Nigeria.
Hydrogen Peroxide and Silver Ion Mixture
This method couples the antibacterial effectiveness of hydrogen peroxide with silver ions’ long-term antibacterial properties.
Effectiveness: Utilised in hospitals and institutions in Europe, it has been shown to act against Legionella, E. coli, and biofilms
Benefit: Long residual activity and non-toxic residues.
Plant-Based Purifiers (Moringa Oleifera Seeds)
locally named “Zogale,” in certain parts of Nigeria, seeds of moringa contain coagulants that clarify turbid water by absorbing suspended matter and bacteria.
Efficacy: Can remove up to 99% of bacteria from turbid water when combined with filtration.
Benefit: Affordable and environmentally friendly
Drawback: Best used for clarification, not disinfection alone.
Conclusion
Chlorine will likely remain a part of Nigeria’s water infrastructure due to its affordability and residual protection, but it shouldn’t be the only method.
Its potential health risks and chemical load on the environment can’t be ignored. Ozone, UV, silver-hydrogen peroxide, and even moringa represent viable, cleaner alternatives, each with its merits and downsides.
With access to clean water, an inalienable right for all citizens, investment in new, science-driven alternatives for chlorine isn’t just a choice. It is a necessity for a healthier, more resilient future.
Chlorine has long been the main disinfectant for drinking water globally, including in Nigeria where 99.8% of water-treatment facilities use it due to its effectiveness and affordability. However, the chemical's overuse has resulted in issues such as a noticeable chemical taste in tap water and health concerns like gastrointestinal disease and cancer due to byproducts like trihalomethanes (THMs). As these health risks become more prominent, there's a push for safer, eco-friendly alternatives to chlorine.
Several alternatives have been proposed, including ozone, which is more effective than chlorine in killing microbes and leaves no residue; UV radiation, which kills microorganisms' DNA efficiently without altering water's taste; a hydrogen peroxide and silver ion mixture with long-lasting antibacterial effects; and plant-based purifiers from Moringa Oleifera seeds, which clarify turbid water. Each method has its strengths and limitations, such as cost, need for infrastructure, or scope of efficacy.
Despite its benefits, chlorine should not be the sole method due to its potential health risks and environmental impact. The highlighted alternatives represent promising, cleaner options for water disinfection. Transitioning to these methods is vital for ensuring Nigerians' access to clean, safe water, signifying a necessity for sustainable and health-focused investments in water purification.
