Annals. Food Science and Technology 2018 Available on-line at www.afst.valahia.ro 21 Volume 19, Issue 1, 2018 KINETIC STUDY OF XANTHENE FOOD DYE SORPTION ON AGRICULTURAL BYPRODUCT Laura Carmen Apostol 1,2 , Maria Gavrilescu 2,3 1 Faculty of Food Engineering, ”Stefan cel Mare” University of Suceava, Romania 2 Department of Environmental Engineering and Management, Faculty of Chemical Engineering and Environmental Protection, “Gheorghe Asachi” Technical University of Iasi, Romania *E-mail: laura.apostol@fia.usv.ro Abstract Erythrosine B is an important representative of the xanthene dye class, widely used in food, pharmaceutical and cosmetic industry. The local agriculture byproduct namely beans hulls was used to identify the interactions between the xanthene foods dye Erythrosine B with its components. The process was studied at natural solution pH (5.6) and a sorbent dosage of 20 g/L representing the favorable adsorption conditions established in the previous investigations. The amount of dye adsorbed was found to vary with initial dye concentration and contact time. The data obtained from Erythrosine B sorption onto beans hulls was interpreted using four types of kinetics models: Lagergren pseudo-first- order, Ho’s pseudo-second-order, Elovich and Weber and Morris intraparticle diffusion model. According to the values obtained for correlation coefficient (R 2 >0.99), the adsorption data fitted the pseudo-second- order model. The two and three linear section with different slope (for concentration higher than 10 mg/L) was assigned to two/three interparticle diffusion steps occurring during the adsorption process of the dye. The rate of Erythrosine B uptake onto beans hulls was found to be controlled by intraparticle diffusion considering that at last one stage has negative intercept values for three (10 mg/L, 30 mg/L and 50 mg/L) of the five studied concentrations. Keywords: Beans hulls, Erythrosine B, kinetic models, sorption mechanism Received: 28.11.2017 Reviewed: 24.01.2018 Accepted: 06.03.2018 1. INTRODUCTION Food dyes are one of the most widely used and dangerous additives that have been around for a long time. They are synthesized originally from coal tar and now petroleum and have long been controversial because of safety concerns. Artificial food dye consumption has increased and children are the biggest consumers. Erythrosine B (CI 45,430) is an important representative of the xanthene dye class, widely used in food, pharmaceutical and cosmetic industry (Apostol and Gavrilescu, 2013). Despite its acceptance to be used, the dye effects have been represented by behavior disorder in children (Silbergeld et al., 1982) and, due to the high iodine content, interference with thyroid function and, due to the high iodine content, interference with thyroid function (Bora et al., 1969; Drumond et al., 2012; Jennings et al., 1990). The wastewater containing dyes is currently of major concern at global level whereas the volume of m 3 /day (Ministry of the Environment, 2007). The fate of Erythrosine B in the environment is less investigated. There is a lake of data regarding the amount of Erythrosine B in real aqueous effluents. Several studies regarding the removal this dye from artificial aqueous solution has been reported in the last period (Apostol and Gavrilescu, 2013). The studies are based on degradation methods: the photochemical degradation of Erythrosine B can lead to the formation of toxic byproducts (Apostol et al., 2015), while the biodegradation process indicated that the decolorization of the dye may be due to enzymatic and adsorption phenomena, with inhibitory effect at high dye concentrations (Apostol et al., 2012). In this context the sorption process is often one of the effective methods to removes hazardous dyes from aqueous media. The low-cost, easily to obtained, highly efficient adsorbents has been investigated as a sustainable alternative to