Monitoring N : P Ratio and Cd, Cu, Pb, and Zn Contents in Different Types of Anaerobic Digestates: A Six-Year Study Case

Table 1

Input material and operating parameters of the four biogas plants included in the study and given designations of the resulting digestates (“DG”).

Plant	A	B	C	D
Input	53% cattle slurry	38% pig slurry	50% maize silage	25% Cattle slurry
	37% maize silage	38% maize silage	50% grass silage	25% Grass silage
	5% grass silage	14% millet silage		19% Maize silage
	5% other remains	10% grass silage		16% Cattle manure
				15% Rye and rye silage
Operating temperature	Mesophile	Mesophile	Thermophile	Mesophile
Retention time	70 days	60 days	50 days	80 days
Related products	“DG cattle” and “Cattle slurry”	“DG pig”	“DG renew”	“DG Mix liquid” and “DG Mix solid”