LAUSR

An optimization study has been carried out on remediation of alkaline bauxite residue (ABR) using peat, sawdust, and gypsum. The results for the tolerance index (TI) and analysis of variance revealed that the order of effective amendments for ABR revegetation was gypsum > peat > sawdust. Gypsum and peat were statistically inferred to have significant influences on the TI of Atriplex canescens due to their capability to reduce pH, paste extract aluminum, and exchangeable sodium percentage. Peat treatment increased the richness of the rhizosphere-associated microbial community, which may benefit plant–microbe interactions and contribute to Atriplex growth promotion. The optimum operating condition identified by the orthogonal experimental design was the combination of 14% peat, 15% gypsum, and 8% sawdust. Application of the gypsum and peat combination holds great potential to enhance ABR remediation.