Removal of arsenic from acid mine drainage by indigenous limestones

摘要

This study was carried out with the aim of evaluating the use of indigenous limestones in an open system channel to retain As from acid mine drainage. To achieve this goal, limestones were collected at the historical mining zone of Zimapán, México. Batch and column experiments were performed with synthetic leachates obtained from two tailing ponds with different oxidation degrees. Results of mineralogi- cal (XRD, FTIR-ATR and SEM-EDS), physico-chemical parameters, arsenic and heavy metals concentrations were interpreted to determine removal mechanisms. Formation and sorption on iron oxyhydroxides and on calcite, and probably arsenates precipitation were identified as the main processes influencing As retention. Relevance of oxidation conditions is highlighted for an adequate operation of the system.