Lead removal from aqueous solution by spherical agglomeration using an extract of Agave lechuguilla torr. As biosurfactant

This study focused on determining the optimal conditions for lead removal in aqueous solution models, by the spherical agglomeration technique (SAT), modifying the dose of Agave lechuguilla Torr. (lechuguilla) extract, used as biosurfactant. The SAT operating conditions at room temperature were: Initial pH 9, and constant agitation ω = 600 rpm. Experiments were performed under a 5x3 factorial design with five lechuguilla extract doses (0.3 - 2.0 g extract/g of pollutant), three different lead concentrations (1, 5 and 10 mg/L) and, for the SAT last stage, two different dosage ratio of CaCl2 (10:1 and 20:1 parts of Ca2+ by part of pollutant). Residual lead, sodium and calcium were determined by atomic absorption spectroscopy. According to statistical analysis, significant effects were observed for calcium dosages, initial lead concentration, extract dose and their interaction. The lead removal efficiency obtained by SAT reached 99.8%.

Keywords: Agave lechuguilla, biosurfactants, saponins, hydrophobization, spherical agglomeration, residual lead.