Potassium mining activities result in the discharge of highly saline wastewaters, creating severe environmental impacts in water and soil. This study evaluates the environmental performance of a novel pilot system developed in the framework of the LIFE Brine-Mining project. The system comprises membrane, precipitation and thermal technologies, recovering high-purity water and five valuable resources from it: magnesium hydroxide, calcium carbonate, calcium sulfate, sodium chloride, and potassium chloride. A cradle-to-grave Life Cycle Assessment (LCA) was performed following the standards ISO14040 and EN15804 and using 1 m³ of potassium wastewater as functional unit. The LCA results indicated that the novel system environmental impact is mainly affected by the use of chemicals (20.63 × 10⁰ kg/FU) during its operation and energy consumption (1.39 × 10¹ kWh/FU). The chemical use dominates areas like the Abiotic Depletion, and the Eutrophication Potential, and the Water Depletion Potential. The novel pilot system was compared with another novel configuration that treated a brine from coal mining activities and with a conventional method of potassium brine management, which is the disposal in underground old mines. The potassium brine treatment system exhibited lower environmental impact than the coal mine brine system, and outperformed compared to the conventional disposal method.

The environmental management of highly saline coal mine wastewater presents a critical challenge for European mining regions, particularly under the constraints of the EU Water Framework Directive. This study presents a cradle-to-grave life cycle assessment of a novel zero liquid discharge (ZLD) system developed under the EU-funded LIFE Brine-Mining project and deployed at the Ziemowit mine in Poland. The system was designed to treat coal mine brine (TDS ~80 g/L) and recover valuable resources, including high-purity water, sodium chloride, magnesium hydroxide, calcium carbonate, and calcium sulphate. The assessment was conducted in accordance with EN 15804 using the Environmental Footprint v3.1 methodology, ecoinvent v3.10, and a functional unit of 1 m³ of saline wastewater inflow, covering all life cycle stages from raw material extraction to end-of-life and resource recovery (Module D). The results indicate a fossil-based global warming potential of 73.86 kg CO₂ eq. per functional unit, with 66% attributed to operational electricity consumption (module B6, 44 kWh/m³) and 29% to auxiliary chemical consumption (module B1). Three key environmental hotspots were identified: module B1 dominates ozone depletion potential (67%), module B6 dominates acidification potential (66%), and raw material extraction (module A1) dominates abiotic depletion of minerals and metals (43%). Resource recovery credits (Module D) offset 11.80 kg CO₂ eq. of GWP-fossil, cause the ADP-minerals and metals indicator to become net negative, and reduce the water deprivation potential by approximately 50%. A sensitivity analysis confirmed that results are robust to ±10% variations in wastewater inflow, with GWP-total varying within a narrow −0.5% to +0.6% range once the volume-proportional nature of chemical and electricity consumption is correctly accounted for. These findings provide a quantitative sustainability baseline for the scale-up and replication of integrated ZLD technologies in the European mining sector, demonstrating that circular brine treatment can simultaneously address regulatory water quality targets, reduce primary resource consumption, and deliver measurable environmental credits aligned with EU circular economy and sustainable development objectives.

Food waste (FW) valorization through resource recovery is central to circular economy strategies that reduce environmental burden while generating sustainable, bio-based chemicals. This work investigated the effect of anaerobic sludge inoculum and the process control parameters of temperature (35 °C and 55 °C), pH value (4–10), and total solids content (2.5%, 5%, 7.5% and 10%) on the recovery of volatile fatty acids (VFAs)—chemicals used in bioplastics and bioenergy production—during acidogenic fermentation of food waste in batch reactors. While FW is well studied for biogas production, its potential for VFA recovery, a strategy that adds economic value to waste streams and supports the circular bioeconomy, remains comparatively underexplored. Mesophilic conditions favored fermentation over thermophilic conditions, and pH was the most influential factor affecting VFA accumulation, although temperature, inoculum presence, and total solids content also had statistically significant, large effects. Basic pH values provided maximum VFA yields from 2% to 25%, roughly double the acidic pH yields, while the highest solids content (10%) minimized VFA production at both temperatures. The highest yield (25%) occurred at T = 35 °C, pH 9, and TS = 5%, without sludge, while the highest yield under thermophilic conditions (T = 55 °C) reached 22.4% at TS = 2.5% and pH 9. By systematically evaluating these parameters together, this study offers a more comprehensive understanding of FW acidogenic fermentation than prior single-parameter works, guiding bioprocess design for sustainable waste management and resource efficiency.