Fig. 6: Control products of Fe2+.
From: Transformation of siderite to goethite by humic acid in the natural environment
Representative SEM images of the synthesized siderite after reacting with 0.56 mg/L (a, d) and 112 mg/L (b, e) Fe2+; c the rest concentration of Fe after reaction; and f the XRD pattern of the synthesized siderite after reacting with different concentration Fe2+. Samples were freeze-dried for 12 h after 7 days of aging.
