They have found ways to make waste water cleanThey gave him ameal for his wonderful work变被动

They have found ways to make waste water cleanThey gave him ameal for his wonderful work变被动
They have found ways to make waste water clean
They gave him ameal for his wonderful work变被动

They have found ways to make waste water cleanThey gave him ameal for his wonderful work变被动
He was given a meal for his wonderfu work.
Ways have been found to make waste water clean.

1.The ways to make waste water clean were found by them.
2.He was given ameal for his wonderful work by them.
P.S.
ameal我不知道是什么意思。别叫我翻译.

Ways to make waste water clean have been found by them
A meal was given to him (by them)for his wonderful work