Stability constants of complexes of metal ions with peatsoil humic acids under non-acid-conditions

  • Yusuf Sabo
  • W.L.O. Jimoh
  • Isa Baba Koki
  • Q.O. Sholadoye
Keywords: stability constant, humic acid, potentiometric titration, divalent metals, acid hydrolysis.


Stability constants of complexes of four divalent metal ions viz. Cu2+, Pb2+,Mg2+ and Cd2+  with humic acids (HA) were determined by potentiometric titration of humic acids with the corresponding salt of the divalent metals in aqueous media under non-acid-condition. The log K (logarithm of the stability constant) ranged from 1.0942 to 2.7471 for metal-humic acid complexes were determined using point-wise computational method. The order of stability constants were obtained as follows: Cu >Pb> Cd > Mg for metal -HA complexes respectively, indicating a higher degree of complexation with Cu metal ion. 


Journal Identifiers

eISSN: 2006-6996
print ISSN: 2006-6996