Metal ion and contaminant sorption onto aluminium oxide-based materials: A review and future research

Nanosized aluminium oxides (NAOs) are an important class of minerals widely found in soil, sediment, aquifer, and aquatic environments. Over the decades, these minerals have been explored as sorbents for the removal of wastewater contaminated with metal ions, anions, organic dyes, humic substances, phenolic compounds, pesticides, and pharmaceuticals from contaminated wastewater. This review summarizes the reported research of NAOs as sorbents and provides details on their sorption capacities including maximum removal capacity under various experimental conditions. Information on the composition, synthesis, characterization and experimental parameters together with sorption mechanisms is provided. A compilation of such information is not currently available and so this review should enable workers in the area to make more informed choices on suitable sorbents for large-scale environmental samples and be able to develop more efficient processes for environmental pollutant clean-up.