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

Figure 5

SEM images of MnO₂ samples synthesized at different molar ratios of KMnO₄/HCl: (a) 1 : 1; (b) 1 : 2; (c) 1 : 4; (d) 1 : 8 (experimental conditions: hydrothermal time and temperature are 16 h and 160°C, respectively).

(a)

(b)

(c)

(d)