Banana Peel as an Adsorbent for Removing Atrazine and Ametryne from Waters Claudineia R. Silva,* Taciana F. Gomes, Graziela C. R. M. Andrade, Sergio H. Monteiro, Ana C. R. Dias, Elias A. G. Zagatto, and Valdemar L. Tornisielo NAPTISA, Centre for Nuclear Energy in Agriculture, University of Sã o Paulo, Box 96, 13400-970 Piracicaba, SP, Brazil ABSTRACT: The feasibility of using banana peel for removal of the pesticides atrazine and ametryne from river and treated waters has been demonstrated, allowing the design of an efficient, fast, and low-cost strategy for remediation of polluted waters. The conditions for removal of these pesticides in a laboratory scale were optimized as sample volume = 50 mL, banana mass = 3.0 g, stirring time = 40 min, and no pH adjustment necessary. K F(sor) values for atrazine and ametryne were evaluated as 35.8 and 54.1 μgg -1 (μL mL -1 ) by using liquid scintillation spectrometry. Adsorption was also evaluated by LC-ESI-MS/MS. As quantification limits were 0.10 and 0.14 μgL -1 for both pesticides, sample preconcentration was not needed. Linear analytical curves (up to 10 μgL -1 ), precise results (RSD < 4.5%), good recoveries (82.9-106.6%), and a > 90% removal efficiency were attained for both pesticides. Water samples collected near an intensively cultivated area were adequately remedied. KEYWORDS: banana peel, river waters, treated waters, atrazine, ametryne, water remediation ■ INTRODUCTION The pronounced increase in human population during recent decades has led to an enhancement of industrial activity and related environmental problems. As a result of the hostile action taken by mankind to maintain the quality of life, pollution of soil, air, and water bodies is already part of everyday life. Among the degradation that has occurred over the past years, water pollution is one of the utmost concerns. This environmental problem is mostly related to the food industry and mining and agriculture activities that generate a considerable amount of toxic wastes. In this context, contamination of surface and ground waters by pesticides used in farming has become a serious environmental concern due to the extensive application of pesticides. 1,2 This contamination can be caused by runoff, heap leaching, wind erosion, industrial discharges, etc., and the potential toxicity of the pesticides has motivated continuous research for remediation purposes. 3 Several environmental protection agencies 4-6 provide guidelines to control waste disposal and recommend limiting quantities and concentrations considered to be toxic to terrestrial flora and fauna. It is then advised to establish plans and goals for maintenance and preservation to ensure quality and potability of groundwater reserves and surface waters. Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-tria- zine) and ametryne (N-ethyl-N-(1-methylethyl)-6-(methyl- thio)-1,3,5-triazine-2,4-diamine) have been widely used as pesticides, with selective action in the pre- and postemergence agricultural crops, mainly sugar cane. 7 Due to their high solubility in water, these pesticides may themselves constitute sources of contamination of water bodies. 8,9 In the European Community, the maximum allowable levels of pesticides in drinking water are 0.1 μgL -1 for each individual substance and 0.5 μgL -1 for the sum of all present pesticides. 5 In Brazil, the maximum allowable concentration for atrazine was established as 2.0 μgL -1 , and there is no recommendation for ametryne. 4 To remove these pesticides from water, several strategies involving, for example, adsorption, photocatalysis, and/or advanced oxidation processes, have been used. 10 With regard to adsorption, adsorbents of natural origin (e.g., vegetable biomass) have become attractive in view of the availability of abundant supplies, high adsorption capacity, and low cost. This is a remarkable aspect, especially if regional biomass is used. The use of agricultural waste complies well with the strategies of treatment of effluents with high efficiency and economic viability. Several studies have been carried out to identify new adsorbents for removing heavy metals, colorants, phenolic compounds, and agrochemicals in environmental samples; among them, the bran and rind of rice, 11,12 watermelon rind, 13 wheat bran, 14 carbon sludge, 15 and coal ash 16 have been highlighted. Banana peel has been used as adsorbent for heavy metals 17 and phenolic compounds; 18 application to atrazine was recently reported. 19 Banana, Musa spp, is a worldwide consumed tropical fruit and comprises several varieties, the most cultivated being known as Nanica. The main importers are the United States, Germany, and Japan, and the per capita consumption is higher in some African, Caribbean, and Polynesian countries. In 2007, the annual per capita consumption in Brazil was estimated as 30.76 kg. 20 Banana peel is the main residue, corresponding to 30-40% (w/w), and has been mainly used in composting, animal feeding, and the production of proteins, ethanol, methane, Special Issue: Florida Pesticide Residue Workshop 2012 Received: November 6, 2012 Revised: January 8, 2013 Accepted: January 10, 2013 Published: January 10, 2013 Article pubs.acs.org/JAFC © 2013 American Chemical Society 2358 dx.doi.org/10.1021/jf304742h | J. Agric. Food Chem. 2013, 61, 2358-2363