Study of Precipitating Methods for Elimination of Heavy Metals from Acid Mine Drainage

Alena Luptáková,Eva Mačingová,Stefano Ubaldini,Ingrida Kotuličová

doi:10.2478/v10296-012-0015-y

Abstract

Abstract The submitted paper deals with the study of combination of chemical and biological-chemical methods for the heavy metals elimination from the acid mine drainage. The experiments were carried out at the laboratory scale using a synthetic solution with similar properties to the real sample of acid mine drainage, originating from the zinc mine located in Tùnel Kingsmill outflow of the Rio Yaulì (district of Yauli - Perù). The successive repetition of the metal precipitations as hydroxides (chemical method) and sulphides (biological-chemical method) at the various acid mine drainage pH was the basis of the examined processes. For the hydrogen sulphide production the sulphate-reducing bacteria of genus Desulfovibrio were used. Results confirmed the precipitation of Fe, As, Al and Mn in the hydroxide form; Cu and Zn in the form of sulphides. For the selective removal of Cu, Zn, Al and Mn the excellent results were received. Selective precipitation of Fe and As was not so successful since the co-precipitation of Fe and As was later determined as a main mechanism of the precipitate forming.

Highlights

Acid mine drainage (AMD) represents the major environmental problem especially associated with mining activities
The basis of the AMD generation is the oxidation of pyrite and other sulphidic minerals exposed to both oxygen and water
The experiments were carried out at the laboratory scale using a synthetic solution of AMD coming from the zinc mine located in Tùnel Kingsmill outlet of the Rio Yaulì

Summary

Introduction

Acid mine drainage (AMD) represents the major environmental problem especially associated with mining activities. Each AMD has a specific composition, but always contains high concentration of the sulphuric acid, dissolved heavy metals, sulphates, iron precipitates and their pH values can be very low. Various methods are used for the treatment of AMD but any of them have not been applied under the commercial-scale. In general two strategies - active and passive technologies - for treating AMD are used: (SKOUSEN et al, 1998; BALINTOVA and LUPTAKOVA, 2012). In the conventional treatment system alkaline materials and other chemicals are added to the AMD to neutralize it and enhance hydroxide precipitation. Each metal in aqueous solution contributes to the AMD acidity.

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Conclusion