Removal of Pb(II) from Aqueous Solutions with Manganese Oxide-Modified Diatomite

Figure 3

SEM images of Mn/diatomite samples prepared at different hydrothermal times: (a, b) 24 h; (c, d) 48 h (experimental conditions: hydrothermal temperature of 80°C and molar ratio of KMnO₄/HCl 1 : 4).

(a)

(b)

(c)

(d)