Table 6 Concentration (mg/kg) of ions and heavy metals in treated wastewater secondary sludge (biosolids) after acidified (with aqua regia) EK (at 16 h at 60 A/m2) and pectin treatment.

From: Molecular and ionic-scale chemical mechanisms behind the role of nitrocyl group in the electrochemical removal of heavy metals from sludge

Metal

Concentratio (mg/kg)

Regulatory standard (Unrestricted use*)

Regulatory standard (Controlled use**)

Mg

<LOD

N/A

N/A

S

21925.98

N/A

N/A

P

12937.61

N/A

N/A

K

822.31

N/A

N/A

Ca

1362.94

N/A

N/A

Sc

11.55

N/A

N/A

Cr

<LOD

400

1000

Mn

<LOD

N/A

N/A

Fe

5547.46

N/A

N/A

Cu

374.14

150

1000

Zn

93.35

300

2500

Rb

26.18

N/A

N/A

Sr

14.61

N/A

N/A

Cd

12.24

N/A

N/A

Pb

<LOD

N/A

N/A

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