Terrestrial biotic ligand model. 2. Application to Ni and Cu toxicities to plants, invertebrates, and microbes in soil.

The Terrestrial Biotic Ligand Model (TBLM) is applied to a number of noncalcareous soils of the European Union for Cu and Ni toxicities using organisms and endpoints representing three levels of terrestrial organisms: higher plants, invertebrates, and microbes. A comparison of the TBLM predictions to soil metal concentration or free metal ion activity in the soil solution shows that the TBLM is able to achieve a better normalization of the wide variation in toxicological endpoints among soils of disparate properties considered in this study. The TBLM predictions of the EC50s were generally within a factor of 2 of the observed values.

A terrestrial biotic ligand model. 1. Development and application to Cu and Ni toxicities to barley root elongation in soils.

A Terrestrial Biotic Ligand Model (TBLM) was developed using noncalcareous soils from Europe based on Cu and Ni speciation and barley (Hordeum vulgare cv. Regina) root elongation bioassays. Free metal ion (M2+) activity was computed by the WHAM VI model using inputs of soil metal, soil organic matter, and alkali and alkaline earth metals concentrations, and pH in soil solution.

Copper activity in soil solutions of calcareous soils.

Copper partitioning was studied in seven calcareous soils at moisture content corresponding to 1.2 times the field moisture content (soil water potential 7.84 J kg(-1)).

Effect of soil properties on copper release in soil solutions at low moisture content.

Copper partitioning at moisture content of 1.2-fold the field moisture capacity (corresponding to a soil water potential of 7.84 J/kg; pF = 1.

Modeling kinetics of Cu and Zn release from soils.

Kinetics of Cu and Zn release from soil particles was studied using two surface soils with a stirred-flow method. Different solution pH, dissolved organic matter (DOM) concentrations, and flow rates were tested in this study. A model for kinetics controlled sorption/desorption reactions between soils and solutions was globally fit to all experimental data simultaneously.