Fig. 2: Characterization of the precipitates.
From: Transformation of siderite to goethite by humic acid in the natural environment
Representative SEM (a and d) and TEM (b and e), HRTEM (c and f), and SAED (g) images of the precipitates of siderite after reacting with HA (2 mg/L); the XRD (i) pattern of the synthesized siderite after reacting with 0 mg/L (i-A), 0.5 mg/L (i-B), 1 mg/L (i-C), 2 mg/L (i-D) and 10 mg/L HA (i-E); schematic diagrams of goethite (h and j) unit cell structures, which were drawn by the Diamond 3.2 software (Crystal Impact GbR, Germany). Samples were freeze-dried for 12 h after 7 days of aging. The concentration of dissolved oxygen (DO) were 4 mg/L.
