Removal efficiency of heavy metals from laboratory wastewater containing ligands by an aluminium hydroxide co‐precipitation system

The aluminum co‐precipitation process is one of the usual methods to remove heavy metals from laboratory wastewater: however, ligands contained in the wastewater can interfere with the process. Heavy metal removal efficiency was measured at various initial concentrations of heavy metal and ligands. Zinc was used as a heavy metal. and sulfate was used as a ligand. A quantitative representation of zinc removal efficiency can be proposed from the standpoint of chemical equilibrium. A combination of mathematical and chemical analyses can simulate the dissolution of zinc hydroxide by ligands in wastewater, as well as the flocculation of zinc hydroxide by aluminum hydroxide prior to dissolution.