Bentonites as adsorbents of heavy metals ions from mine waste leachates: Experimental data

摘要

Bentonite is a clay raw material with high cation exchange capacity because of their typical layered silicate structure. Experimental studies about the retention of metals (Cu, Co, Ni, and Zn) in Peruvian bentonite have been accomplished for monometallic, bimetallic, trimetallic, and tetrametallic solutions. The influence of parameters such as concentration of metals in solution, and pH, has been considered by means of batch adsorption experiments. Adsorption rates indicate the suitability of these materials to be applied in the environmental industry for retention of heavy metals from mine waste leachates. Then, in addition to its quality as physical barrier to avoid the dispersion through the environment of polluted leachates, bentonite, due to its high cation exchange capacity acts as a chemical barrier too, protecting the quality of surface and groundwater systems. They have in consequence a potential use as screen material, to create security barriers limiting the migration of heavy metals content in mine wastes or tailings stocked in security landfills in surface spaces or in underground cavities.