例句與造句

1. An initial scheme, the Ludzack-Ettinger Process, placed an anoxic treatment zone before the aeration tank and clarifier, using the return activated sludge ( RAS ) from the clarifier as a nitrate source.
2. The sludge in the anoxic tanks ( denitrification tanks ) must be mixed well ( mixture of recirculated mixed liquor, return activated sludge [ RAS ], and raw influent ) e . g . by using submersible mixers in order to achieve the desired denitrification.
3. It's difficult to find return activated sludge in a sentence. 用return activated sludge造句挺難的