A comprehensive review of integrated phytoremediation and nanoparticle methods for heavy metal in red mud

Abstract

Red mud (RM), a waste product from the processing of bauxite ore used in the alumina industry, has high salinity and alkalinity levels as well as a number of heavy metals that can cause environmental issues. Global environmental concerns about the appropriate management of RM have arisen because of the leaching risk of heavy metals and the rising annual production of RM. In the past 20 years, phytoremediation has become a well-known and environmentally friendly metal removal technique. However, challenges such as poor plant development limit the effectiveness of traditional red mud phytoremediation. It has been extensively demonstrated that using nanoparticles to improve phytoremediation efficiency is preferable. This study presents a comprehensive review of the potential of a combined technology strategy involving phytoremediation and nanotechnology to treat red mud. The physical and chemical properties of RM and its potential for contamination were thoroughly examined from the perspective of RM formation. Second, the physiological, morphological, and biochemical parameters of red mud were used to comprehensively evaluate possible heavy metal accumulator species. Third, the material type, characteristics, and role of nanoparticles in phytoremediation were highlighted. Finally, a perspective on the challenges of applying nanoparticle-assisted phytoremediation strategies to red mud was proposed for further development.