Environmental Toxicology and Chemistry, Vol. 33, No. 3, pp. 508–515, 2014 # 2013 SETAC Printed in the USA
SORPTION AND DESORPTION OF ALCOHOL SULFATE SURFACTANTS IN AN AGRICULTURAL SOIL CAROLINA FERNÁNDEZ-RAMOS,y OSCAR BALLESTEROS,y ALBERTO ZAFRA-GÓMEZ,y ROSARIO BLANC-GARCÍA,y ALBERTO NAVALÓN,y SARA ISABEL CROVETTO,y BARTOLOME OLIVER-RODRÍGUEZ,y RAFAEL ANTONIO GARCÍA-DELGADO,z and JOSE LUÍS VÍLCHEZ*y yResearch Group of Analytical Chemistry and Life Sciences, Department of Analytical Chemistry, University of Granada, Granada, Spain zInstituto Geológico y Minero de Espa~ na, Granada, Spain (Submitted 10 July 2013; Returned for Revision 19 August 2013; Accepted 20 November 2013) Abstract: Alcohol sulfates are one of the most important types of commercial anionic surfactants and may pose serious environmental problems. The present study examines the sorption behavior of alcohol sulfates in an agricultural soil using a batch reactor and column experiments. Kinetics and equilibrium isotherms of the sorption and desorption processes of the following alcohol sulfate homologues have been determined: AS-C12, AS-C14, AS-C16, and AS-C18. Sorption and desorption occurred rapidly, and equilibrium was achieved in approximately 1 h. The sorbed mass percentages were 35.1% AS-C12, 67.2% AS-C14, and 100% for both AS-C16 and AS-C18. A pseudo– first-order kinetic model provided an adequate fit of data. Sorption and desorption equilibrium data were fitted into 1) a linear model, with r2 values in the ranges 0.712 to 0.988 and 0.736 to 0.983, respectively, and 2) a Freundlich model, with r2 values in the ranges 0.956 to 0.991 and 0.891 to 0.981, respectively. Continuous-flow experiments in soil columns were carried out to obtain the breakthrough curves for each compound. The present study provides basic theoretical concepts and key parameters for developing mathematical models that simulate the migration of alcohol sulfate into agricultural soils. Environ Toxicol Chem 2014;33:508–515. # 2013 SETAC Keywords: Alcohol sulfate
Agricultural soil
Sorption
Equilibrium and kinetics
Column experiment
well documented in the literature [9–11]; for example, Jensen et al. [12] reported that immediately after agricultural soil was amended, the measured concentrations were between
SORPTION AND DESORPTION OF ALCOHOL SULFATE SURFACTANTS IN AN AGRICULTURAL SOIL CAROLINA FERNÁNDEZ-RAMOS,y OSCAR BALLESTEROS,y ALBERTO ZAFRA-GÓMEZ,y ROSARIO BLANC-GARCÍA,y ALBERTO NAVALÓN,y SARA ISABEL CROVETTO,y BARTOLOME OLIVER-RODRÍGUEZ,y RAFAEL ANTONIO GARCÍA-DELGADO,z and JOSE LUÍS VÍLCHEZ*y yResearch Group of Analytical Chemistry and Life Sciences, Department of Analytical Chemistry, University of Granada, Granada, Spain zInstituto Geológico y Minero de Espa~ na, Granada, Spain (Submitted 10 July 2013; Returned for Revision 19 August 2013; Accepted 20 November 2013) Abstract: Alcohol sulfates are one of the most important types of commercial anionic surfactants and may pose serious environmental problems. The present study examines the sorption behavior of alcohol sulfates in an agricultural soil using a batch reactor and column experiments. Kinetics and equilibrium isotherms of the sorption and desorption processes of the following alcohol sulfate homologues have been determined: AS-C12, AS-C14, AS-C16, and AS-C18. Sorption and desorption occurred rapidly, and equilibrium was achieved in approximately 1 h. The sorbed mass percentages were 35.1% AS-C12, 67.2% AS-C14, and 100% for both AS-C16 and AS-C18. A pseudo– first-order kinetic model provided an adequate fit of data. Sorption and desorption equilibrium data were fitted into 1) a linear model, with r2 values in the ranges 0.712 to 0.988 and 0.736 to 0.983, respectively, and 2) a Freundlich model, with r2 values in the ranges 0.956 to 0.991 and 0.891 to 0.981, respectively. Continuous-flow experiments in soil columns were carried out to obtain the breakthrough curves for each compound. The present study provides basic theoretical concepts and key parameters for developing mathematical models that simulate the migration of alcohol sulfate into agricultural soils. Environ Toxicol Chem 2014;33:508–515. # 2013 SETAC Keywords: Alcohol sulfate
Agricultural soil
Sorption
Equilibrium and kinetics
Column experiment
well documented in the literature [9–11]; for example, Jensen et al. [12] reported that immediately after agricultural soil was amended, the measured concentrations were between
