Partition of copper between dissolved and particulate phases using aluminum oxide as an aquatic model phase: effects of pH, solids and organic matter

Abstract

The sorption of copper ions from aqueous solutions onto modified aluminum oxide was investigated as a function of pH, solids concentration and both particulate and dissolved organic matter. The aluminum oxide studied was modified by adsorption of humic acid. The pH value, organic matter content, and solids concentration dominated copper adsorption onto modified aluminum oxide. The adsorption of copper increased with increasing pH. An increase in particulate organic carbon resulted in an enhanced copper uptake. The partition coefficient (Kd) of copper decreased as the solids concentration increased. Copper partitioning was maximal in the neutral pH range and decreased at either low or high pH values. There was also a decrease in copper adsorption with increasing dissolved organic matter concentration.

Keywords

• copper
• aluminum oxide
• partitioning
• natural waters
• humic acids