The removal of pollutants and natural organic compounds from acid mine drainage using a combination of bentonite clay and MgSO4

I O Ntwampe

doi:10.2166/wpt.2021.015

Abstract

Abstract 200 mL of synthetic acid mine drainage (AMD) sample was poured into five 500 mL glass beakers and treated in a jar test and a shaker in sets of experiments, respectively. The samples were treated in small-scale laboratory experiments using synthetic AMD sample dosed with bentonite clay and MgSO4 respectively, and a flocculant consisting of the same reagents. The pH, EC, turbidity and oxidation reduction potential were measured. The removal of turbid materials in the samples dosed with a flocculant is higher compared to those of the samples dosed with each reagent alone. The samples with flocculant dosage show high removal efficiency of natural organic compounds and toxic metals, slightly higher compared to those with a dosage of a combination of bentonite clay and MgSO4. The removal efficiency of the samples treated in a shaker is better than those with rapid mixing. The SEM micrographs show sorption is a physico-chemical phenomenon.

Highlights

Conventional wastewater treatment has been employed in colloidal suspensions of various types, where inorganic coagulants are widely used
The statistical analysis of the turbid materials removal efficiency of the acid mine drainage (AMD) samples dosed with a combination of bentonite clay and MgSO4 is illustrated in Table A1 (Appendix)
The main objective of this study was to investigate the efficiency of a flocculant consisting of bentonite clay and MgSO4 in the removal of a composite AMD sample

Summary

Introduction

Conventional wastewater treatment has been employed in colloidal suspensions of various types, where inorganic coagulants are widely used. Countries rich in mineral resources such as gold and coal face acid mine drainage (AMD) decanting problems. It is imperative to investigate a cost-effective AMD treatment method in order to curb such water shortage crises. The load of AMD can be quite complex as it has high mineral dissolving capacity due to low pH. It flows vertically and horizontally, dissolving all soluble materials, treatment can be difficult at times. Research has shown that there are on-going studies investigating an ideal technology viable in the treatment of AMD. Some of the studies conducted by Gupta et al (2012) and Saravanan et al (2015a, 2015b, 2015c) have shown high performance in the removal of turbid materials, equipment and methodologies employed in some of them are costly and sophisticated

Objectives

Methods

Results

Conclusion