Green-KAT - Green Inhibitors for Koralmtunnel

The formation of unwanted mineral deposits (scaling) and corrosive processes disturbing water transport in railway- and highway tunnels (drainages) and installations for hydrogeothermal energy production (thermal water wells) constitute a common operational and cost intense challenge for maintenance of the geotechnical infrastructure. The addition of specific chemical agents (inhibitors) can provide an efficient preventive measure against problematic crystal nucleation and chemical sedimentation from diverse aqueous solutions. Our applied research and consulting activities focus on the investigation of different eco-friendly, biodegradable and typically non-phosphorus chemical additives counteracting widespread Ca-carbonate precipitation. Different commercially available and “green” inhibiting agents, products, variable dosages, as well as blended inhibitors are evaluated based on compact testing procedures (experiments) in the laboratory and site-specifically in the field. Dataloggers involving different electrodes and optical sensors allow for high (temporal) resolution online and on-site monitoring of the crystallization processes vs. inhibitor effects. This includes the assessment of inhibitor-specific reduction and retardation efficiencies, spontaneous nucleation in suspension vs. nucleation on preexisting substrates and varied Ca-carbonate material consistencies. The analytical (fluids, solids) and monitoring results are combined with computer-based hydrogeochemical modeling.