Adsorción de metales pesados en aguas residuales usando materiales de origen biológicoAdsorption of heavy metals in waste water using biological materialsCandelaria Tejada-Tovar 1 , Ángel Villabona-Ortiz 2 y Luz Garcés-Jaraba 3Recibido: 10 de junio de 2014, Aceptado: 26 de octubre de 2014Cómo citar / How to cite C. Tejada-Tovar, A. Villabona-Ortiz y L. Garcés-Jaraba, "Adsorción de metales pesados en aguas residuales usando materiales de origen biológico", Tecno Lógicas, vol. 18, no. 34, pp. 109-123, 2015 ResumenLa bioadsorción es un proceso que permite la captación activa o pasiva de iones metálicos, debido a la propiedad que diversas biomasas vivas o muertas poseen para enlazar y acumular este tipo de contaminantes por diferentes mecanismos. La aplicación de materiales de bajo costo obtenidos a partir de diferentes biomasas provenientes de la flora microbiana, algas y residuos agroindustriales ha sido investigada para reemplazar el uso de métodos convencionales en la remoción de contaminantes, tales como los metales pesados. Entre los metales de mayor impacto al ambiente por su alta toxicidad y difícil eliminación se encuentran el cromo, níquel, cadmio, plomo y mercurio. En el presente trabajo se estudian las generalidades de la adsorción como proceso alternativo para la remoción de contaminantes en solución y las biomasas comúnmente usadas en estos procesos, además de algunas de las modificaciones realizadas para la mejora de la eficiencia de adsorción de las mismas. Se concluye que el uso de la adsorción en la remoción de contaminantes en solución acuosa mediante el uso de biomasa residual es aplicable a estos procesos de descontaminación evitando problemas subsecuentes como la generación de lodos químicos, y generando un uso alternativo a materiales considerados como desechos. Se identifica además que factores como el pH de la solución, tamaño de partícula, temperatura y la concentración del metal influyen en el proceso. Palabras claveAdsorción, biosorbentes, efluentes, ion metálico, residual. AbstractBiosorption is a process that allows active or passive uptake of metal ions due to the property that different living or dead biomass have to bind and accumulate these pollutants by different mechanisms. The application of low-cost materials obtained from different biomass from microbial flora, agro-industrial waste and algae has been investigated to replace the use of conventional methods for the removal of contaminants such as heavy metals. Some of the metals of greatest impact to the environment due to its high toxicity and difficult to remove are chromium, nickel, cadmium, lead, and mercury. In this paper, an overview of adsorption as an alternative process for the removal of contaminants in solution and biomass commonly used in these processes, as well as some of the modifications made to improve the efficiency of adsorption of these materials is presented. It was concluded that the use of adsorption in the removal of pollutants in aqueous solution using waste biomass is applicable to these decontaminatio...

Modelado de la biodegradación en biorreactores de lodos de hidrocarburos totales del petróleo intemperizados en suelos y sedimentos (Biodegradation modeling of sludge bioreactors of total petroleum hydrocarbons weathering in soil and sediments)

The removal of water pollutants has been widely addressed for the conservation of the environment, and novel materials are being developed as adsorbent to address this issue. In this work, different residual biomasses were employed to prepare biosorbents applied to lead (Pb(II)) ion uptake. The choice of cassava peels (CP), banana peels (BP), yam peels (YP), and oil palm bagasse (OPB) was made due to the availability of such biomasses in the Department of Bolivar (Colombia), derived from agro-industrial activities. The materials were characterized by ultimate and proximate analysis, Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller analysis (BET), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS) in order to determine the physicochemical properties of bioadsorbents. The adsorption tests were carried out in batch mode, keeping the initial metal concentration at 100 ppm, temperature at 30 °C, particle size at 1 mm, and solution pH at 6. The experimental results were adjusted to kinetic and isotherm models to determine the adsorption mechanism. The remaining concentration of Pb(II) in solution was measured by atomic absorption at 217 nm. The functional groups identified in FTIR spectra are characteristic of lignocellulosic materials. A high surface area was found for all biomaterials with the exception of yam peels. A low pore volume and size, related to the mesoporous structure of these materials, make these bioadsorbents a suitable alternative for liquid phase adsorption, since they facilitate the diffusion of Pb(II) ions onto the adsorbent structure. Both FTIR and EDS techniques confirmed ion precipitation onto adsorbent materials after the adsorption process. The adsorption tests reported efficiency values above 80% for YP, BP, and CP, indicating a good uptake of Pb(II) ions from aqueous solution. The results reported that Freundlich isotherm and pseudo-second order best fit experimental data, suggesting that the adsorption process is governed by chemical reactions and multilayer uptake. The future prospective of this work lies in the identification of alternatives to reuse Pb(II)-contaminated biomasses after heavy metal adsorption, such as material immobilization.

No abstract

Abstract. Agroindustrial wastes have been widely used to prepare adsorbents for heavy metal removal because of their low cost, accessibility, and high efficiency. This work focuses on preparing a novel material from cocoa ( L.) husk residual biomass chemically modified with sodium hydroxide for used as a biosorbent for nickel and mercury uptake. The cocoa husk residual biomass was characterized by FT-IR analysis to test the diversification of functional groups. The effect of particle size on removal yield was evaluated through batch adsorption experiments. The experimental results were fitted to mathematical models to determine the adsorption kinetics and isotherms. Particle size significantly affected the adsorption process, and the highest removal yields (91.59% and 79.96%) were achieved using 0.36 mm and 0.5 mm particles for Hg (II) and Ni (II) ions, respectively. The adsorption kinetic model that best fit the experimental data corresponded to the Elovich model, with correlation coefficients (R2) above 0.89. The adsorption process of nickel and mercury onto cocoa husk biomass followed the Freundlich isotherm model. The results show that modification with sodium hydroxide improves the adsorption capacity of cocoa husk residual biomass, indicating that this novel material could be efficiently applied for nickel and mercury uptake. Keywords: Adsorption, Heavy metals, Removal yield.