“sludges”簡單造句，sludges造句子

The sewage sludges can be used as amendments on crop land.

The results show that the wastewaters and sludges from two factories are most toxic and can cause serious damage to rice seedlings, and those from other two factories can also cause damage.

Phosphorus fractionation is important too in understanding the biological phosphorus removal process and possibilities to recover phosphorus from sludges.