Reductive dissolution of As(V)-bearing Fe(III)-precipitates formed by Fe(II) oxidation in aqueous solutions

Table 2 Parameters of reductive dissolution kinetics

Label	Wet solids			Dried solids			Ratio dried/wet
Label	t ^a_50% (h)	t ^b_1/2 (h)	k_app (h⁻¹)	t ^a_50% (h)	t ^b_1/2 (h)	k ^c_app (h⁻¹)	For t_50% (−)	For t_1/2 (−)
Ca-00-00	5.4	5.4	0.13	7.4	7.5	0.092	1.36	1.39
Ca-01-00	1.6	1.7	0.41	2.8	2.8	0.25	1.78	1.67
Ca-02-00	1.5	1.5	0.47	2.3	2.5	0.28	1.55	1.70
Ca-05-00	2.7	2.8	0.25	4.3	4.3	0.16	1.63	1.55
Ca-15-00	6.9	6.9	0.10	7.6	7.8	0.089	1.11	1.12
Na-15-00	7.5	7.7	0.090	7.8	8.3	0.084	1.04	1.07
Ca-02-05	2.9	2.6	0.26	4.0	4.2	0.17	1.40	1.58
Ca-02-10	6.2	6.2	0.11	8.0	7.9	0.088	1.12	1.22
Ca-00-10	35	33	0.021	39	40	0.017	1.30	1.26
2L-Fh	5.0	5.6	0.12	27	−	−	5.33	−

^aTime required for the dissolution of 50% of the solids; derived from Figs. 1a, b, 2a, b, Additional file 1: Figures S3ab, and S4a by interpolating data points adjacent to 50% Fe reduction or set to time at which 50% Fe reduction was measured
^bDissolution half-life time t_1/2; calculated from k_app (t_1/2 = ln(2)/k_app)
^cApparent rate coefficient based on the assumption of pseudo-first-order dissolution kinetics; obtained by linear regression of linearized plots of ln(1 − c(t)/Fe_tot) versus t for data points up to 63% Fe dissolution (Figs. 1c, d, 2c, d and Additional file 1: Figure S3cd). The relative standard error for k_app ranged from 0.5 to 5.5%

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