Synthesising acid mine drainage to maintain and exploit indigenous mining micro-algae and microbial assemblies for biotreatment investigations

Abstract

The stringent regulations for discharging acid mine drainage (AMD) has led to increased attention on traditional or emerging treatment technologies to establish efficient and sustainable management for mine effluents. To assess new technologies, laboratory investigations on AMD treatment are necessary requiring a consistent supply of AMD with a stable composition, thus limiting environmental variability and uncertainty during controlled experiments. Additionally, biotreatment systems using live cells, particularly micro-algae, require appropriate nutrient availability. Synthetic AMD (Syn-AMD) meets these requirements. However, to date, most of the reported Syn-AMDs are composed of only a few selected heavy metals without considering the complexity of actual AMD. In this study, AMD was synthesised based on the typical AMD characteristics from a copper mine where biotreatment is being considered using indigenous AMD algal-microbes. Major cations (Ca, Na, Cu, Zn, Mg, Mn and Ni), trace metals (Al, Fe, Ag, Na, Co, Mo, Pb and Cr), essential nutrients (N, P and C) and high SO(4) were incorporated into the Syn-AMD. This paper presents the preparation of chemically complex Syn-AMD and the challenges associated with combining metal salts of varying solubility that is not restricted to one particular mine site. The general approach reported and the particular reagents used can produce alternative Syn-AMD with varying compositions. The successful growth of indigenous AMD algal-microbes in the Syn-AMD demonstrated its applicability as appropriate generic media for cultivation and maintenance of mining microorganisms for future biotreatment studies.

Microalgal Classification

“…C. vulgaris was trialed in that regard and a biosorption of 60 mg Ni g À1 DW was achieved from a water source containing 250 mg L À1 (Aksu, 2002). In this study, rotating biofilm cultivation was used to study the uptake, removal efficiency, and metal release by the biomass, which was enriched with typically present green freshwater microalgae, such as Chlorella, Scenedesmus, Ankistrodesmus, Franceia, Mesotaenium, and cyanobacteria (Orandi and Lewis, 2013, and references therein), which were also essentially present in the HIRAP wastewater treatment study, which suggests that these native microalgal consortia are stable and competent for nutrient-and metal-rich wastewater remediation applications (Figure 2). In this study, rotating biofilm cultivation was used to study the uptake, removal efficiency, and metal release by the biomass, which was enriched with typically present green freshwater microalgae, such as Chlorella, Scenedesmus, Ankistrodesmus, Franceia, Mesotaenium, and cyanobacteria (Orandi and Lewis, 2013, and references therein), which were also essentially present in the HIRAP wastewater treatment study, which suggests that these native microalgal consortia are stable and competent for nutrient-and metal-rich wastewater remediation applications (Figure 2).…”

“…The genus Porphyridium (Porphyridiophyceae C ) has great potential in the production of polysaccharides (Arad and Levy-Ontman, 2010), arachidonic acid (Ahern et al, 1983), or phycobilins (Kathiresan et al, 2007). Lastly, Phycobilins are watersoluble pigments found in the chloroplasts of Rhodophyta, which can be used for a wide range of applications including food and cosmetic colorants (Borowitzka, 2013), biotechnological uses like fluorescent tags for flow cytometry and immunology (Glazer, 1994), or medical uses as photosensitizers in cancer treatment (Hu et al, 2008;Pan et al, 2013). Arachidonic acid from red algae can be used in the same way as from green algae.…”

Eukaryotic Community Structure and Interspecific Interactions in a Stratified Acidic Pit Lake Water in Anhui Province

“…The patterns of microalgae-fungi co-occurrence in extreme environments and their responses to environmental gradients were unclear. Tracking complex microalgae-fungi interactions and designing positive symbiotic community relationships have positive implications for AMD contamination remediation [27].…”

Treatment of acidic sulfate-containing wastewater using revolving algae biofilm reactors: Sulfur removal performance and microbial community characterization

“…Among those industrial effluents, acid mine drainage (AMD) is a particular concern. In addition to high sulfur content, AMD also contains a diverse of metals (Orandi and Lewis, 2013) with an acidic pH ranging from 3.6-4.7 to 1.5 (Abinandan et al, 2018). Researches on AMD treatment have been mainly focusing on metal removal.…”