Environmentally and economically sustainable water treatment system for post-mining waste

Project summary

The environment and water resources in South Africa (SA) are negatively impacted by mining activities. This project creates a research opportunity for treating acid mine drainage (AMD), a type of mining effluent, in an environmentally and socioeconomically sustainable way. While SA has remarkable mineral wealth, the mining industries have left a legacy of negative impacts. Among the most critical of these is AMD, a highly acidic and often toxic waste solution that poses a substantial threat to water resources, aquatic ecosystems, human health, and sustainable socioeconomic development. These are especially relevant to SA as a water-scarce country. This project establishes the potential to unlock alternative water resources and value from AMD through research into a remediation system that removes contaminants, upcycles valuable minerals, and produces clean water and biofuel, whilst understanding the key socioeconomic factors involved. Additional economic value and agency is envisaged at a local scale through the creation of biorefineries utilizing the remediation technology. This project will focus on the Witwatersrand Basin where ground- and surface water suffers from widespread AMD contamination. In this location we are able to base a competent project team comprising leading South African and Danish university partners and private enterprises in a network with authorities, water utilities, mining representatives and local communities. By including the socio-economic value of the proposed research we will demonstrate the relevance of the treatment to wider society and create knowledge for effective, sustainable and science-based policymaking.

Outputs

First year report
Objectives:
Acid Mine Drainage AMD treatment: A sustainable solution is being developed. This involves stepwise technology approaches for key AMD characteristics such as iron removal, and REE extraction undergoing lab trials. Two related papers have been prepared.
Pollution management: Engagement with two major South African mines has expanded the network and capacity.
Technology propagation: An ongoing economic evaluation is underway and has begun to identify key profitability drivers of the process.
Socio-economic benefits: An assessment is in progress, studying potential improved welfare in local communities.
Outputs:
AMD sources: A comprehensive report and map, incorporating global data, is near completion, with sample testing from South African coal fields and their water bodies ongoing.
Iron removal and clean water: Developed lab-scale methods, including ion exchange and electrocoagulation, are under optimization.
Socio-economic benefits: Identifying key value components of AMD remediation is underway through literature review and expert interviews, with focus group interviews set for 2023.
Fuel production: Initial research from organic residues is taking place.
Knowledge dissemination: Achieved via workshops, conferences presentations and two peer reviewed publications.
Partnerships and Joint Activities:
Frequent meetings and workshops have solidified collaborations with mines, universities, and stakeholders like CM solutions, Cwenga, The Moss Group.