PH10 Soil Ecotoxicology and Risk Assessment
Exhibit Hall
8:00 AM - Thursday
(PH137A) Terrestrial Biotic Ligand Model (TBLM) to predict copper toxicity in soil systems.
Thakali, S, Ponizovsky, A, Metzler, D, Allen, H, Di Toro, D, Rooney, C, Zhao, F-J, McGrath, S,
ABSTRACT- The WHAM 6 model (Tipping et al, 1995) was validated for calculating copper activity in soil solutions. This was applied to develop a Terrestrial Biotic Ligand model to predict copper toxicity in soils based on major soil properties and total Cu content in soil. The toxicity test was carried out for 11 soils of Europe with pH range 3.4 to 6.8 and organic matter content 0.4 to 23.3 g C/100g using the ISO 11269-1 barley root elongation method. Calculated Cu2+ activity values corresponding to effective concentrations (EC10 and EC50) were related to basic soil properties. The slopes for pCu values calculated both at EC10 and at EC50 vs. pH were close to unity. This may result from proton competition with Cu2+ at the biotic ligand and formation of monodentate complex of Cu2+ on the surface of barley roots.
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