A review on modified red mud-based materials in removing organic dyes from wastewater:Application, mechanisms and perspectives

Red mud (RM) is a highly alkaline solid waste generated during alumina production and should be disposed of and recycled in an environmentally sound manner. Red mud is rich in metal compounds, making it a promising material for environmental remediation treatment. However, there are fewer papers on the removal of organic dyes from wastewater using modified red mud-based materials. Therefore, this paper provides a comprehensive review on the properties of dyes and reveals the adverse effects caused by dye wastewater pollutants. The application of modified red mud-based materials in dye wastewater are further reviewed. Meanwhile, the removal mechanism includes electrostatic gravitational interaction, hydrogen bonding, π-π bonding, and catalytic oxidation. In addition, this paper suggests that the activation methods for red mud materials should be optimized in future studies as well as develops red mud-based materials with absorbing many dyes. This paper aims to expand modified red mud-based materials application for removing organic pullents from wastewater and red mud utilization.