Fly ash is the fine particulate pollutants produced by the combustion of coal, which are collected rather than allowing them to escape into the atmosphere, then mixed with water and pumped into a retaining pond, where the ash gradually settles to the bottom.
飞灰是煤炭燃烧产生的细粒污染物，它们会被收集起来，不会让它们逃逸到大气中，然后与水混合并泵入蓄水池，在那里煤灰逐渐沉淀到底部。