Sucralose, the artificial sweetener in Splenda, passes right through the body, then through sewage treatment systems and out into surface and ground waters with little degradation. It is not clear if increasing amount of of sucralose released into the environment will impact the ecosystem. But research published in Environmental Engineering Science shows that the artificial sweetener is indeed making it through traditional water filtering systems. The study done at Arizona State University shows the fate of sucralose as it passes from humans into surface waters.
Samples of wastewater were taken from seven wastewater-processing plants in Arizona. Tests showed that both anaerobic and aerobic biological batch reactors showed no significant decrease in the amount of sucralose present. Chlorine, ozone, and ultraviolet light sometimes used in the final stages of wastewater treatment were also not effective at breaking down sucralose.
It might be possible to break down compounds using advanced oxidation processes. Some of these processes have been used in projects aimed at reclaiming municipal wastewater for a variety of applications, including indirect drinking water use. The hydroxyl radical formed in these processes have been shown to degrade virtually all organic compounds including chlorinated organics. On the other hand, sucralose’s resistance to degradation also keeps it from breaking down into highly toxic chlorinated compounds. So its impact on the environment may be muted.