Copper (II) and lead (II) complexation capacity of composts from several wastes

Abstract

Several authors have shown the great importance of organic matter on the bioavailability of metal ions for plants and how formation of complexes can affect their retention and solubility (Harter and Naidu, 1995). Thus, although addition of composts from several wastes to soils as organic amendments is a common practice, their excessive use may cause deficiency or toxicity of heavy metals in some instances. An increase in metal solubility due to formation of soluble complexes with the organic matter dissolved in the soil solution may also cause environmental problems as a consequence of an enhanced mobility, which favours their transport to water courses. Therefore the study of complexes formed between organic amendments and heavy metals may give useful information from the plant nutrition viewpoint as well as for environmental quality purposes.