<i>Arthrospira</i> Sp. Culturing for Sulphate Removal from Mining Wastewater: A Preliminary Study

Abstract

Sulphate content in mining wastewater can reach concentrations over 2000 mg/L and, if untreated, is responsible for causing medical problems on humans and animals. Conventional treatment techniques are based on costly and environmentally harmful processes, so it is a need to find a sustainable approach of these methods. For this study, mining wastewater rich in sulphates was used as culture medium for two Arthrospira species. Strains were selected due to their capacity turn contaminants into added value molecules. The focus of this work was to use this wastewater for algal biomass production, as well as to study the biosorption of sulphate on external algal walls. Results showed how Arthrospira maxima could tolerate the presence of 100% of residue and incorporated up to 23.34% of initial sulphate concentration, which is comparable to the pre-treatments currently used in mining industry. SEM-EDX analysis reported no adsorption of sulphates on cellular surface, proving that sulphate descent was due to metabolic up-taking. Our findings suggest that Arthrospira maxima cultures can be used as part of a novel sulphate bioremediation system and for valuable compounds extraction.