Competitive and non-competitive cadmium, copper and lead sorption/desorption on wheat straw affecting sustainability in vineyards Gustavo F. Coelho a , Affonso C. GonÇalves Jr. a , Juan Carlos N  ovoa-Mu ~ noz b , David Fern  andez-Calvi ~ no b , Manuel Arias-Est  evez b , María J. Fern  andez-Sanjurjo c , Esperanza  Alvarez-Rodríguez c , Avelino Nú ~ nez-Delgado c, * a Center for Agricultural Sciences, Marechal C^ andido Rondon, Paran a, Rua Pernambuco, 1777, CEP 85960-000, State University of West Paran a, Brazil b Department of Plant Biology and Soil Science, Faculty of Sciences, Campus Ourense, Universidade de Vigo, 32004, Ourense, Spain c Department of Soil Science and Agricultural Chemistry, Engineering Polytechnic School, Universidade de Santiago de Compostela, Lugo, 27002, Spain article info Article history: Received 11 June 2016 Received in revised form 3 September 2016 Accepted 3 September 2016 Available online 5 September 2016 Keywords: Desorption Heavy metals Sorption Sustainability Vineyard Wheat straw abstract The novelty of this work lies on the consideration of wheat straw to retain Cu and other heavy metals in vineyards, in addition to its known potential to decrease erosion, thus facilitating the growth of new vine plants and contributing to sustainability in vineyard production. In this study we used batch-type ex- periments to investigate Cd, Cu and Pb competitive and non-competitive sorption/desorption on wheat straw. In non-competitive experiments, sorption sequence was Pb > Cd > Cu when the lowest molar concentrations (0.5 mmol L À1 ) were added, and Pb > Cu > Cd when the highest molar concentrations (6.0 mmol L À1 ) were added. Sorption curves indicated clearly higher sorption for Pb, lower initial sorption in the case of Cu, and certain trend to saturation of sorption sites for Cd. Data showed good adjustment to the Langmuir model just for Cd, whereas the Freundlich equation fitted well for all three metals. Desorption rates were low, in the order Pb < Cd < Cu. In the competitive experiment, the sorption sequence was Pb > Cu > Cd. The results indicate that competition clearly affected to Cd sorption, especially when the highest concentrations (6 mmol L À1 ) of the three heavy metals were added. The highest percentage of desorption in the competitive system corresponded to Cd, whereas Pb and Cu experienced clearly lower release. Comparing competitive and non-competitive experiments, Pb sorp- tion was equivalent in the non-competitive and competitive trials, Cu sorption was slightly higher in the non-competitive than in the competitive experiment, and Cd sorption was clearly higher in the non- competitive trial. Percentage desorption decreased for Pb and for Cu in the competitive trial, whereas it was clearly higher for Cd in the competitive than in the non-competitive experiment. The overall results indicate that Pb, Cu and Cd can be retained by wheat straw (especially Cu and Pb), thus decreasing risks of pollution, which could be used to treat polluted waters, and could also give additional value to wheat straw mulching used to protect vineyards from erosion and Cu (and other heavy metals) pollution, thus contributing to sustainability in this productive sector. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Heavy metals pollution is a global concern, and in the specific case of vineyards is mainly focused on Cu contamination due to the traditional use of Cu-based fungicides in these areas (Kom arek et al., 2010). High Cu concentration may even difficult the growth of new vine plants (Romeu-Moreno and Mas, 1999), thus compro- mising sustainability of this productive sector (sustainability un- derstood as the quality of not being harmful to the environment or depleting natural resources, and thereby supporting long-term ecological balance). However, other heavy metals, such as Cd and Pb, have also been studied in these environments (Kom arek et al., 2008; Herrero-Hern andez et al., 2012; Duplay et al., 2014). In addition to heavy metals pollution, many vineyards are associated * Corresponding author. E-mail address: avelino.nunez@usc.es (A. Nú~ nez-Delgado). Contents lists available at ScienceDirect Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro http://dx.doi.org/10.1016/j.jclepro.2016.09.021 0959-6526/© 2016 Elsevier Ltd. All rights reserved. Journal of Cleaner Production 139 (2016) 1496e1503