Organic amendments enhanced the humification degree in soil formation of bauxite residue

Purpose Revegetation of bauxite residue disposal areas is an effective disposal strategy for large-scale in-situ disposal and reduction of environmental risk. The application of organic amendments is an effective method of increasing the organic carbon content of residue. Humification of bauxite residue by different types of organic amendments in the synergistic effect of Ca-containing solid waste was investigated. Methods 100-day incubation experiments using Fourier Transform Infrared Spectroscopy (FTIR), Excitation-Emission Matrix (EEM) fluorescence, Ultraviolet–Visible (UV–Vis) spectroscopy, Illumina high-throughput sequencing technology for the analysis of bauxite residue treated with different organic amendments. The organic amendments treatments applied included corn straw (BGS), nitrohumic acid (BGH), and poultry manure (BGM), and the pretreated residue (desulphurization gypsum mixed with bauxite residue) was the BG. Results The composition and parameters of humic substances of bauxite residues with different treatments was ranked as BG