They are too small to be captured in waste water treatment plants.

它们太小而无法在废水处理厂中捕获。

Researchers think that tiny flecks of gold are literally washed down the drain in the sewage systems and waste water treatment plants and they believe there's enough of it in some areas that it may actually be worth collecting.

研究人员认为，在污水系统和废水处理厂中，细小的金粒确实被冲进了下水道，他们认为在某些地区金粒数量已经足够，因此可能值得收集。