Work

Electrolytic manganese residue amendment improved the suitability of lead-zinc tailings for plant growth

Year: 2025

Type: article

Abstract: Revegetation is urgently needed for the ecological restoration of lead-zinc tailings ponds. However, the harsh properties of lead-zinc tailings—including poor aggregation, nutrient deficiency, and low water retention capacity—severely hinder plant colonization and growth. This study effectively improved the physical structure and nutrient status of lead-zinc tailings using electrolytic manganese residue (EMR), a solid waste characterized by strong cohesiveness and high ammonium nitrogen content. Moreover, lead-zinc tailings amended with 1 % EMR had low leaching of toxic elements, indicating low environmental risk. X-ray computed tomography and nuclear magnetic resonance analyses revealed that EMR amendment significantly reduced total porosity of lead-zinc tailings while enhancing their water retention capacity ( p < 0.05). The improvements likely resulted from the filling of interparticle voids by EMR clay particles and the formation of Ca₂(AlFe)(Si₂O₇)(SiO₄)O(OH), a hydrated gel similar to the hydrated calcium silicate gel. The hydrated gel formed by the reaction between Ca²⁺ from EMR and silicates on tailing surfaces may increase interparticle cohesion. A pot experiment showed that 1 % EMR amendment significantly promoted ryegrass growth in tailings, increasing fresh biomass by 13.7 % ( p < 0.05). Overall, these findings indicate that EMR amendment is a promising strategy to enhance plant colonization and growth in the revegetation of lead-zinc tailings ponds. • Electrolytic manganese residue (EMR) as an amendment used in lead-zinc tailings. • EMR reduced tailings porosity and enhanced water retention capacity. • EMR add supplement the deficient of nutrients (N, Ca, S, K, Mn) in tailings. • Adding 1 % EMR significantly promoted ryegrass growth in tailings.

Source: Ecotoxicology and Environmental Safety

DOI: 10.1016/j.ecoenv.2025.119158