Table 1 Feed preparation and MEC operation in four experimental sets

Set A

1, 3, 5 SSM cathode pieces

No phosphate addition

Mg:NH₄:PO₄ = 2.0:66:0.43 (mM)

No acetate addition

Set B

1, 3, 5 SSM cathode pieces

1.5 mM Na₂HPO₄ addition

Mg:NH₄:PO₄ = 2.0:66:1.93 (mM)

No acetate addition

Set C

Single SSM cathode piece

1.5, 3.0, 4.5 mM Na₂HPO₄ addition

Mg:NH₄:PO₄ = 2.0:66:1.93–4.93 (mM)

No acetate addition

Set D

Single SSF cathode piece

1.5 mM Na₂HPO₄ addition

Mg:NH₄:PO₄ = 2.0:66:1.93 (mM)

12.2 mM NaCH₃COO addition