Potential Role of Spirogyra sp. and Chlorella sp. in Bioremediation of Mine Drainage: A Review

Abstract

One of the biggest global challenges in the mining industry is managing the risks associated with contamination by potentially toxic elements (PTEs) resulting from their activity. The oxidation of sulfides is the main cause of polluted mine drainage through the leaching of PTEs from mine waste and mine galleries to the water systems. Mine drainage can be highly acidic and often has a high concentration of PTEs, particularly arsenic, one of the environment’s most toxic elements. PTEs endanger the ecosystem’s equilibrium and raise worries about human and animal health. Some species of algae which can be naturally present in mine drainage waters, such as Spirogyra sp. And Chlorella sp., have a high capacity for absorbing PTEs from wastewater and may thrive in harsh environments. As a result, algal-based systems in bioremediation were studied and carefully analyzed, since their capacity to remove heavy metals and hazardous contaminants from polluted mine water have already been shown in previous studies. Biofuels derived from microalgal biomasses are a viable alternative to fossil fuels that can lead to a circular bioeconomy. This study reviews and analyses Chlorophyta-based bioremediation systems with application to mine waters focusing on Spirogyra sp. and Chlorella sp., since they are naturally present in mine drainage and can serve as a study model to better understand their application in bioremediation.

Physicochemical surface properties of Chlorella vulgaris: a multiscale assessment, from electrokinetic and proton uptake descriptors to intermolecular adhesion forces

“…They have also emerged as a potential substrate in bioremediation processes of wastewater and polluted ecosystems through their capacity to adsorb and accumulate toxic compounds. 12–14 In order to enhance their contaminant removal efficiency, various strategies have been proposed, such as cells immobilization or development of algal consortia in biofilm-based cultures ( cf. e.g.…”

“…As an illustration, strong variations of pH, as met in acid mine drainage, can dramatically affect the bioremediation capacity of microalgae due to unfavourable change in their electrostatic interactions with heavy metals. 12 Besides, proper modification of pH condition in cell culture media is one of the possible microalgae harvesting method employed to generate auto-flocculation 21–23 or enhance the effects of flocculants. 24,25…”

Cadmium and COD Removal from Municipal Wastewater Using Chlorella sp. Biomass in Microbial Fuel Cells

“…On the other hand, it has been shown that microalgae and cyanobacteria carry out oxygenated photosynthesis even with small amounts of photosynthetic oxygen, help in electrogenesis, wastewater treatment (via anodic oxidation and cathodic reduction), and CO 2 capture (via cathodic reduction) [21,22]. Also, it has been shown that even small amounts of photosynthetic oxygen in the anode of microbial fuel cells have been able to benefit the growth of heterotrophic bacteria, which has managed to generate an certain level of electrical current [23,24].…”