waste activated sludge

例句：

1. 1. The treatment plant uses wasteactivated sludge to treat the wastewater.
   处理厂使用废水污泥来处理废水。
2. 2. The waste activated sludge isa valuable resource for fertilizer production.
   废水污泥是肥料生产的一种宝贵资源。
3. 3.The waste activated sludge needs tobe properly managed to prevent environmental pollution.
   废水污泥需要妥善管理，以防止环境污染。