Skip to main content

Table 1 Results of the adsorption/desorption of N2 at 77 K in ferrihydrite and effect of sodium chloride concentration and initial pH values on the pH at the point of zero charge (pHPZC)

From: The effect of pH and ionic strength on the adsorption of glyphosate onto ferrihydrite

Applied method Ferrihydritea Ferrihydrite + glyphosateb  
BET surface area (m2 g−1) 234 196  
BJH pore volume (cm3 g−1) 0.116 0.091  
DH pore volume (cm3 g−1) 0.115 0.091  
BJH pore size (nm)a 1.69 1.68  
DH pore size (nm)a 1.69 1.68  
[NaCl]/mol L−1 pHPZC
Glyphosate/µmol
0.0 0.0 41.4
Without pH adjust pH = 5.0
0 8.47 7.76 4.96
0.01 8.20 7.08 5.10
0.1 8.33 8.52 4.99
  1. BET Brunauer–Emmett–Teller, BJH Barrett–Joyner–Halenda, DH Dollimore-Heal
  2. a Pore radius, b ferrihydrite used as synthesized, c ferrihydrite plus 30.0 µmol of glyphosate dissolved in 10 mL of 0.10 mol L−1 of NaCl at pH = 5.0. For the experiments of pHPZC was used an initial pH of 5.0. For all experiments was used 60 mg of ferrihydrite. The results were a mean of two experiments