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The widespread use of artificial sweeteners in foods, drinks, and pharmaceuticals has led to rising concentrations in wastewater, with specific sweeteners raising concerns due to demonstrated toxicological risks to ecosystems and humans. To date, a comprehensive summary of the occurrence, distribution, and removal status of artificial sweeteners in wastewater treatment plants (WWTP) is lacking, making it difficult to evaluate the associated risks and environmental impacts. We conducted a systematic review of scientific literature and grey literature with rigorous screening covering 24 countries and 6 continents. Globally, sucralose, acesulfame, saccharin, and cyclamate are prevalent artificial sweeteners in WWTP, with concentrations of 0.6-303.0 µg/L in influent and 0.1-81.2 µg/L in effluent. Sucralose showed obvious increasing concentrations over time in wastewater in the United States and Canada, with an increase of 5.6-5.7 µg/L·y in influent and 4.7-5.5 µg/L·y in effluent. Summer wastewater usually contains 11.1-33.3 % higher concentrations of artificial sweeteners than other seasons. Saccharin and cyclamate are the most easily removable sweeteners (>90.0 % removal) in WWTP, followed by acesulfame (25.0-70.1 %) and sucralose (-10.0-10.0 %). Wastewater treatment processes with longer HRT and more diverse microbial communities showed better performance in sucralose removal, while processes with aerobic conditions showed better performance in acesulfame and saccharin removal than anaerobic processes. Increasing trends for persistent sucralose and acesulfame removal have been observed globally, suggesting potential microbial evolution/adaptation. This review contributes to a comprehensive understanding of the spatiotemporal distribution and ever-evolving biodegradation of artificial sweeteners in WWTP, providing future perspectives and potential policy requirements.
Li et al. (Fri,) studied this question.