Abstract

MURGUEITIO, Erika; PINTO, Willian  and  LANDIVAR, José. Chrome VI removal from synthetic water level laboratory, using layered double hydroxides (HDL). Rev. Soc. Quím. Perú [online]. 2015, vol.81, n.2, pp.160-170. ISSN 1810-634X.

Four types of double layered hydroxides (HDL) were synthesized with Al / Mg molar ratio of 4:1, using analytical and technical grade reagents. Batch essays were conducted in which it was determined that the adsorption capacity of chromium VI is proportional to the initial concentration, to the four adsorbents (α = 0,05; F> F critical). It was also determined that it is viable the use of lower cost technical grade reagents for the synthesis, since the adsorbents have similar level of efficiency, both with sintetic water (distilled water with competing ions: 80 ppm HCO₃^-, 100 ppm Cl^-, 120 ppm SO₄= and different concentrations of Cr VI) and industrial water. In batch equilibrium tests with synthetic water it was established a 54% of adsorption; with industrial water about 19% was obtained, both at 120 minutes. The isotherm model that fits the adsorption behavior is Freundlich which indicates a multilayer adsorption. Adsorption kinetics is consistent with the pseudo-first order model, which is a physical adsorption and ion exchange. In a fixed bed column with synthetic water 70% removal of chromium VI was achieved. When industrial water was treated the removal reached to 98.4% and thus the values remained below the permissible limit for discharge to drain. The using of HDL in a fixed bed column at pH 2,8 significantly decreases chromium VI from the effluent in chrome industry appliances. Is recommended the Use of HDL to treat highly polluted effluents and to transfer them to a solid matrix, easily manageable for environmental managers

Keywords : Laminar double hydroxide; chromium VI; adsorption; kinetics; isotherm.

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