title: Cadmium mobility in sediments and soils from a coal mining area on Tibagi River watershed: environmental risk assessment.
abstract: The risk of cadmium contamination in the Tibagi River watershed (Parana State, Brazil) affected by past coal mining activities was assessed through sorption-desorption modeling for sediment and soil samples. The acidic character of the samples resulted in more competition between the cadmium ions and protons, thereby influencing the cadmium sorption-desorption. The sorption isotherms were fitted to the Langmuir and Freundlich single models and to the dual-site Langmuir-Freundlich (or Sips) model. The single-site models indicated a low-energy character of sorption sites on the sample sorption sites, whereas the dual-site model explained the availability of higher-affinity and lower-affinity non-specific sites. The correlation of the sorption and desorption constants with the physicochemical and mineralogical characteristics of the samples showed that the cadmium sorption behavior was significantly affected by the pH, point of zero charge, and also by the magnesium, aluminum, calcium and manganese amounts. Besides, the desorption rate and hysteresis index suggested a high risk of cadmium mobilization along the Tibagi River basin.
authors: Departamento de Química, Universidade Estadual de Londrina, Rod. Celso Garcia Cid - PR 445, 86051-990 Londrina, Brazil.
authors: Evgeny
authors: E
authors: Galunin
authors: Departamento de Química, Universidade Estadual de Londrina, Rod. Celso Garcia Cid - PR 445, 86051-990 Londrina, Brazil.
authors: Jeferson
authors: J
authors: Ferreti
authors: Departamento de Química, Universidade Estadual de Londrina, Rod. Celso Garcia Cid - PR 445, 86051-990 Londrina, Brazil.
authors: Iago
authors: I
authors: Zapelini
authors: Departamento de Química, Universidade Estadual de Londrina, Rod. Celso Garcia Cid - PR 445, 86051-990 Londrina, Brazil.
authors: Isadora
authors: I
authors: Vieira
authors: Departamento de Química, Universidade Estadual de Londrina, Rod. Celso Garcia Cid - PR 445, 86051-990 Londrina, Brazil.
authors: César
authors: C
authors: Ricardo Teixeira Tarley
authors: Departamento de Engenharia Elétrica, Universidade Estadual de Londrina, Rod. Celso Garcia Cid - PR 445, 86051-990 Londrina, Brazil.
authors: Taufik
authors: T
authors: Abrão
authors: Departamento de Química, Universidade Estadual de Londrina, Rod. Celso Garcia Cid - PR 445, 86051-990 Londrina, Brazil. Electronic address: mjyabe@uel.br.
authors: Maria Josefa
authors: MJ
authors: Santos
mesh_terms: D000327:Adsorption; D001938:Brazil; D002104:Cadmium / Q000737:chemistry*; D003032:Coal Mining; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D018570:Risk Assessment; D045483:Rivers; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D002104:Cadmium
keywords: Cadmium; Freundlich–Langmuir model; Soils and sediments; Sorption–desorption isotherms