Fig. 5. (a and b) Effect of pH on BPS and BPA adsorption onto COF-1 and COF-2; (pH = 4–11, C₀ = 30 mg L⁻¹, T = 303 K, t = 3 h, m/V = 0.2 g L⁻¹); (c) zeta potential of COF-1 and COF-2; (d and e) the effect of ions strength on BPS and BPA adsorption onto COF-1 and COF-2 (NaCl concentration = 0–1 mol L⁻¹, C₀ = 30 mg L⁻¹, T = 303 K, t = 3 h, m/V = 0.2 g L⁻¹).