title: Quantifying chemical reactions by using mixing analysis.
abstract: This work is motivated by a sound understanding of the chemical processes that affect the organic pollutants in an urban aquifer. We propose an approach to quantify such processes using mixing calculations. The methodology consists of the following steps: (1) identification of the recharge sources (end-members) and selection of the species (conservative and non-conservative) to be used, (2) identification of the chemical processes and (3) evaluation of mixing ratios including the chemical processes. This methodology has been applied in the Besòs River Delta (NE Barcelona, Spain), where the River Besòs is the main aquifer recharge source. A total number of 51 groundwater samples were collected from July 2007 to May 2010 during four field campaigns. Three river end-members were necessary to explain the temporal variability of the River Besòs: one river end-member is from the wet periods (W1) and two are from dry periods (D1 and D2). This methodology has proved to be useful not only to compute the mixing ratios but also to quantify processes such as calcite and magnesite dissolution, aerobic respiration and denitrification undergone at each observation point.
authors.affiliation: GHS, Institute of Environmental Assessment & Water Research (IDAEA), CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain; GHS, Dept. Geotechnical Engineering and Geosciences, Technical University of Catalonia, UPC-Barcelona Tech, Jordi Girona 1-3, 08034 Barcelona, Spain. Electronic address: annajuradoelices@gmail.com.
authors.forename: Anna
authors.initials: A
authors.lastname: Jurado
authors.affiliation: GHS, Institute of Environmental Assessment & Water Research (IDAEA), CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Enric
authors.initials: E
authors.lastname: Vázquez-Suñé
authors.affiliation: GHS, Institute of Environmental Assessment & Water Research (IDAEA), CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Carrera
authors.affiliation: GHS, Dept. Geotechnical Engineering and Geosciences, Technical University of Catalonia, UPC-Barcelona Tech, Jordi Girona 1-3, 08034 Barcelona, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Tubau
authors.affiliation: GHS, Institute of Environmental Assessment & Water Research (IDAEA), CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain; GHS, Dept. Geotechnical Engineering and Geosciences, Technical University of Catalonia, UPC-Barcelona Tech, Jordi Girona 1-3, 08034 Barcelona, Spain.
authors.forename: Estanislao
authors.initials: E
authors.lastname: Pujades
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D060587:Groundwater / Q000737:chemistry*; D008956:Models, Chemical; D013030:Spain; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical
keywords: Chemical reaction quantification; Mixing analysis; Non-conservative species; Urban aquifer