Abstract
This thesis explored the fermentation of agricultural residues, specifically apple pomace (AP) and potato peel waste (PPW), for the development of bio-based deicing formulations aimed at supporting climate-smart winter mobility. Fermentation of AP and PPW was carried out using mixed microbial cultures to produce solutions rich in organic compounds, which were subsequently incorporated with sodium metasilicate and sodium chloride to formulate deicers. The performance of these formulations was evaluated using freezing-point depression (DSC), ice-melting capacity, corrosion rate, freeze-thaw durability, and chemical oxygen demand (COD) analyses.The results showed that the bio-based formulations exhibited ice-melting performance comparable to that of conventional NaCl brine, with melt volumes reaching approximately 1.47 mL g⁻¹ within 20 minutes. Freezing point depression was enhanced by the presence of organic solutes, indicating improved low-temperature performance. Corrosion rate testing demonstrated that several bio-enhanced formulations significantly reduced corrosion rates compared to NaCl brine, with values as low as approximately 0.012 mm y⁻¹, whereas the NaCl control exhibited higher corrosion rates of approximately 0.025 mm y⁻¹. Freeze-thaw durability testing revealed that the compressive strength of Portland cement mortar (PCM) after exposure ranged from approximately 9.4 to 27.7 MPa, with certain formulations maintaining higher structural integrity than others. COD analysis indicated that bio-based formulations had high organic load, reflecting the presence of biodegradable constituents.
A multi-criteria decision analysis using the Analytical Hierarchy Process (AHP) identified optimal formulations that balanced ice-melting performance, corrosion mitigation, and durability. Although the use of mixed microbial cultures (MMC) introduced variability in fermentation products and experiments were conducted under controlled laboratory conditions, the results demonstrate that fermentation-derived additives combined with sodium metasilicate have strong potential as sustainable additives to conventional chloride-based deicers. These findings highlight the feasibility of using agricultural-industrial waste streams to develop environmentally friendly, effective deicing solutions for winter road maintenance.