A Review of the Current State, Challenges and Emerging Trends for Sustainable Tailings Remediation in South Africa: Transforming Mine Tailings Dumps into Bioenergy Hotspots

Globally, mining waste-related problems are regarded as the second most significant environmental issue after global warming and ozone depletion. Although the techniques for extracting precious metals have greatly improved, the increasing scarcity of these metals has resulted in a substantial rise in mine waste. The limitations of traditional remediation methods have led to the adoption of phytoremediation, a plant-based technology, for environmentally friendly and cost-effective detoxification and contaminant removal from soil. Over the past three decades, phytoremediation has attracted considerable interest and research attention. This literature review aims to synthesize the current state of knowledge on phytoremediation, focusing on leveraging bioenergy production. The review further examines species suitable for phytoextraction, phytostabilization, and bioenergy production, along with the limitations of current legislation in promoting a more integrated approach to mitigate the environmental and social impacts of mining, as well as the extensive use of plant species to address metal contamination in South Africa's mining industry. Among other species, Vetiver grass was evaluated for its potential in integrated phytoremediation, carbon sequestration, and bioenergy production systems. The review identified a disconnect between legislation and the current environmental, social, and economic sustainability, which frustrates the country's sustainable development agendas and the adoption of a circular economy. It also highlighted the lack of information regarding potential synergies between phytoremediation, bioenergy production, and carbon sequestration in South Africa. Thus, more work is needed to establish a new paradigm for rehabilitating mined land to tackle the interconnected challenges of mining-related pollution control, energy production, and climate change. This promotes the integration of circular economy principles, innovation, and sustainability.