Concentration in STP sludge Concentration in farmyard compost Sludge
K 2858.95 5171.93
Na 1162.75 1764.79
Ca 1655.58 1999.02
B 28.92 13.23
Mn 115.18 137.33
Fe 6169.52 7836.75
Co 2.12 2.36
Ni 12.42 7.77
Cu 40.29 32.09
Zn 230.3 156.97