Biosolids Soil Application: Why a New Special on an Old Issue?

An extensive body of scientific evidence has recognized that biosolids should not be seen just as a waste, but could be beneficially recycled as a soil conditioner because of its stable organic matter matrix. The fertilizer value of biosolids has also been extensively researched. Consequently, a worldwide massive biosolids’ use as soil conditioner and fertilizer arose in the early 1900s.Whilst recognising its significant value as a resource, recycling sewage sludge to agricultural land requires a careful management to avoid potential negative impacts on the environment from chemical contaminants. Among them, potentially toxic elements and organic chemicals are usually transferred to biosolids during waste water treatment process. As a consequence, in the 1990s there was pressure in some European countries to ban the use of biosolids for agricultural use.