Which chemical process is often faced with difficulty regarding residual stability?

Ozonation is often faced with challenges related to residual stability due to the nature of ozone as a disinfectant. Ozone is a powerful oxidant and is effective at killing bacteria, viruses, and other pathogens in water. However, one of its characteristics is that it has a very short half-life. When ozone is introduced into water, it decomposes rapidly into oxygen, which means that there is little residual ozone left in the water after the treatment process is complete.

This rapid decomposition results in a challenge for ensuring long-term disinfection residual in the distribution system. Unlike chlorine, which can maintain a residual concentration in water for an extended period, ozone does not provide this sustained residual, making it difficult to ensure that the water remains free of pathogens during transport to consumers. Consequently, while ozonation may be effective in treating water, the lack of a stable disinfectant residual is a key consideration that must be managed.