Fig. 4

Performance of SCP-IHEP-1 for ReO₄⁻ removal. a Sorption kinetics with that of Cu-bpy used as a comparison; b sorption isotherms with that of Cu-bpy used as a comparison; c effect of pH on the removal percentage of ReO₄⁻ (c₀ = 44.6 mg L⁻¹, T = 300 K, t = 12 h, V = 8 mL, and m = 4 mg); d effect of competing anions on the ReO₄⁻ exchange (c₀ = 45.0 mg L⁻¹, t = 12 h, T = 300 K, V = 8 mL, m = 4 mg, and pH = 6.92); e effect of excess NO₃⁻ on the ReO₄⁻ exchange (c₀ = 45.0 mg L⁻¹, t = 12 h, T = 300 K, V = 8 mL, m = 4 mg, and pH = 6.85); f effect of excess SO₄²⁻ on the ReO₄⁻ exchange (c₀ = 45.0 mg L⁻¹, t = 12 h, T = 300 K, V = 8 mL, m = 4 mg, and pH = 7.05). Error bars represent the s.d. of uncertainty for each point