Copper monoethanolamine adsorption in wood and its relation with cation exchange capacity (CEC)

Abstract

Abstract To investigate the chemical adsorption capacity of copper-monoethanolamine (Cu-Mea) components on wood, the Na+ cation exchange capacity (CEC) of red pine (Pinus resinosa Ait.) was determined and compared with the adsorption capacity of free Mea, Cu2+ and Cu-Mea complexes. Red pine showed higher CEC as pH increased. Free Mea adsorption as a function of pH followed the Na adsorption curve except at pH over 9, when it exceeded the CEC. Below pH 5, where Cu-Mea complexes do not form, divalent Cu2+ was adsorbed as if it were monovalent. Cu-Mea adsorbed up to the CEC at pH 9.0–9.5 apparently as [CuMea]+, whereas the complex in solution is predominantly of the form [Cu(Mea)2]+. FTIR analysis showed that the same sites of wood are related to Mea, Na, and Cu adsorption.