Micellar-enhanced ultrafiltration process (MEUF) for removing copper from synthetic wastewater containing ligands

The effects of the type and concentration of ligands on the removal of Cu by micellar-enhanced ultrafiltration (MEUF) with the help of either anionic or cationic surfactants were investigated. The removal efficiency of copper by anionic surfactant-(SDS-) MEUF depends on the ligand-to-Cu ratio and the ligand-to-Cu complexation constant. At fixed ligand-to-Cu ratio, the Cu removal efficiency decreases in the order of citric acid>NTA>EDTA, which is the reverse order of Cu-ligand complexation constants for these ligands. Increasing SDS-ligand ratios from 12 to 60 at fixed ligand concentration did not improve copper removal efficiency. The cationic surfactant, CPC, enhances Cu removal efficiency in systems with condition of ligand-copper ratios higher than 1.0, where Cu removal is not very efficient using SDS-MEUF process. The Cu removal efficiency with CPC-MEUF depends on both the ligand-to-Cu ratio and the type of ligands.