The role of cation exchange in the sorption of cadmium, copper and lead by soils saturated with magnesium.
The displacement of Ca(2+), Mg(2+), K(+) and Al(3+) from the A and Bw or Bt horizons of two soils developed over serpentinized amphibolites when equilibrated in Cu(2+), Cd(2+) or Pb(2+) solutions was determined, together with the concomitant sorption of the heavy metal. The contributions of Mg(2+) to the effective cation exchange capacities of the A and Bt horizons of the Endoleptic Luvisol were 57% and 94%, respectively, and its contributions to those of the A and Bw horizons of the Mollic Cambisol were 70% and 77%, respectively. In all four horizons, cation exchange, chiefly with Mg(2+) and Ca(2+), was the process chiefly responsible for sorption of Cd(2+), Cu(2+) and Pb(2+). Al(3+) and K(+) were hardly implicated, especially in the case of Cd(2+).
Vega
F A
FA
Departamento de Bioloxía Vexetal e Ciencia do Solo, Facultade de Bioloxía, Universidade de Vigo, Lagoas, Marcosende, 36310 Vigo, Pontevedra, Spain. florav@uvigo.es
Covelo
E F
EF
Andrade
M L
ML
D000327:Adsorption; D000535:Aluminum / Q000737:chemistry; D002104:Cadmium / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry; D002412:Cations / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D004784:Environmental Monitoring; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis; D010316:Particle Size; D011188:Potassium / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*
D002412:Cations; D019216:Metals, Heavy; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead; D003300:Copper; D000535:Aluminum; D008274:Magnesium; D011188:Potassium; D002118:Calcium