Engineering Functionalized Hybrid Sorbent Materials Based on Lignin for Purifying Mining Wastewater: Sorb4MINE

Research question

Current methods for mining wastewater purification have drawbacks such as inefficiency, high costs, and the use of potentially harmful chemicals; at the same time it is well known that functional polymers, produced from renewable and low-cost resources as alternatives to traditional synthetic ion exchangers and membranes are excellent sorbent candidates for the removal of toxic compounds from wastewaters. This, together with the fact that lignin is an excellent functional polymer candidate, abundantly available from numerous pulping processes, yet unvalorized partly due to its complicated structure and limited solubility, form the basis for the main research question to be addressed, viz; if it is possible to develop a new synthetic road to obtain functionalized KL-alumina composites through high-speed mechanical grinding by ball milling with a minimum of solvent usage, instead activating KL by chemical treatment, to overcome difficulties related to the complex structure and low solubility of KL.

The goal is, hence, to produce efficient, scalable, and cost-effective materials with enhanced sorption capacity, selectivity, fast adsorption kinetics, stability, and reusability to ultimately create bio-based materials with superior functional performance and environmental footprint for large-scale mining wastewater recycling compared to existing petroleum-based materials, such as synthetic plastics, membranes, and ion-exchangers.

Sustainability aspects

Globally, mining poses a threat to freshwater sources through extensive water usage in ore processing and pollution from mine effluent discharge, endangering vital water supplies and, hence, making water earn the label of “mining’s most common casualty.” Our project aligns with several UN Sustainability Goals including SDG 6 (safe water access and freshwater ecosystem management), SDG 9 (sustainable industry, innovation, and infrastructure), SDG 12 (responsible consumption and production), and indirectly SDG 13 (climate action) due to the link between pollution and climate change. Given Sweden’s abundant wood biomass, our project also offers a sustainable method for industrial wood biomass utilization, in line with SDG 9, potentially revolutionizing sugar-based biorefineries by valorizing lignin residue, leading to economic benefits for bioeconomy companies and fostering innovation in green biomaterials.