Cu 2

Metal ion stock solutions were prepared by adding chloride salts to a final concentration of 100 mM in dH₂O. Two different synthetic microbicidal mixtures (SMM3 and SMM16) were prepared by diluting metal ion stocks in dH₂O to the concentrations found in CB07-L [1] (link). Elemental chemistry of the CB leachates was previously measured by inductively coupled plasma mass spectrometry (ICP-MS) (described in Otto et al. [1] (link)), and ion concentrations from these ICP-MS measurements were used to prepare SMM3: Li (Sigma), 7.62 µM; Be(II) (Sigma), 0.80 µM; Na (Fisher), 171.61 µM; Mg(II) (Sigma), 773.11 µM; Al(III) (Sigma), 1079.6 µM; Ca(II) (Sigma), 6911.18 µM; Ti(IV) (Sigma), 0.01 µM; V(III) (Sigma), 0.49 µM; Mn(II) (Sigma), 99.31 µM; Fe(III) (Sigma), 229.88 µM; Co(II) (Sigma) 3.38 µM; Ni(II) (Sigma), 3.46 µM; Cu(II) (Sigma) 3.18 µM; Zn (Sigma) 14.52 µM [1] (link). The pH of the solution was adjusted to 3.5 with 1 M NaOH, and the solution was sterilized by passage through a 0.22 µM filter prior to further use. SMM16 was prepared in an identical manner as described above with the following metal ion concentrations: Fe(III), 200 µM; Co(II), 4 µM; Cu(II), 80 µM; Zn, 40 µM.