In order to ensure the safety of fertilizer products, environmental
legislation has been tightening gradually in the 2000s
(Marttinen et al., 2013). Fig. 4 illustrates the treatment requirements
for different raw materials and the associated legislative
framework. The treatment and utilization of AD residues are regulated
in the Finnish National Fertiliser Product Act (539/2006),
Ministry of Agriculture and Forestry Decree 24/11 (Record No
1784/14/2011) on fertilizer products, European Parliament and
Council Regulation 1069/2009, and its complementary act No
142/2011.