In a trench dug by a University of South Florida Coastal Research Lab team, layers of oil-stained sand light up orange under ultraviolet light. Clean sand appears violet.

南佛罗里达大学海岸研究实验室的团队挖掘的一条地沟，沾了油污的沙子在紫外线下为橙色，而干净的沙子为紫色。

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Crowds abandon their browsing to step onto the sand and watch the sky light up in blistering reds and oranges.

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Urine is filtered through sand, and the resulting fluid is sterilised with ultraviolet light.

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