title: Assessment by self-organizing maps of element release from sediments in contact with acidified seawater in laboratory leaching test conditions.
abstract: Carbon capture and storage (CCS) is gaining interest as a significant global option to reduce emissions of CO2. CCS development requires an assessment of the potential risks associated with CO2 leakages from storage sites. Laboratory leaching tests have proved to be a useful tool to study the potential mobilization of metals from contaminated sediment in a decreased-pH environment that mimics such a leakage event. This work employs a self-organizing map (SOM) tool to interpret and analyze the release of dissolved organic carbon (DOC), As, Cd, Cr, Cu, Ni, Pb, and Zn from equilibrium, column, and pH-dependent leaching tests. In these tests, acidified seawater is used for simulating different CO2 leakage scenarios. Classification was carried out detailing the mobilization of contaminants for environments of varying pH, liquid-to-solid ratio, and type of contact of the laboratory leaching tests. Component planes in the SOMs allow visualization of the results and the determination of the worst case of element release. The pH-dependent leaching test with initial addition of either base or acid was found to mobilize the highest concentrations of metals.
authors.affiliation: GER Green Engineering and Resources Group, Department of Chemistry and Process & Resource Engineering, ETSIIT, University of Cantabria, Avda. de los Castros s/n 39005, Santander, Cantabria, Spain. itziarmdiaz@gmail.com.
authors.forename: I
authors.initials: I
authors.lastname: Muñoz
authors.affiliation: GER Green Engineering and Resources Group, Department of Chemistry and Process & Resource Engineering, ETSIIT, University of Cantabria, Avda. de los Castros s/n 39005, Santander, Cantabria, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: Martín-Torre
authors.affiliation: GER Green Engineering and Resources Group, Department of Chemistry and Process & Resource Engineering, ETSIIT, University of Cantabria, Avda. de los Castros s/n 39005, Santander, Cantabria, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Galán
authors.affiliation: GER Green Engineering and Resources Group, Department of Chemistry and Process & Resource Engineering, ETSIIT, University of Cantabria, Avda. de los Castros s/n 39005, Santander, Cantabria, Spain.
authors.forename: J R
authors.initials: JR
authors.lastname: Viguri
mesh_terms: D000143:Acids; D002244:Carbon; D002245:Carbon Dioxide / Q000032:analysis*; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000032:analysis; D008956:Models, Chemical; D012623:Seawater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000143:Acids; D008670:Metals; D014874:Water Pollutants, Chemical; D002245:Carbon Dioxide; D002244:Carbon
keywords: Carbon capture and storage; Leaching tests; Metal-release assessment; Sediment acidification; Self-organizing maps