Browsing by Author "Reyes Bozo, Lorenzo"

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    Bioremediation of contaminated mixtures of desert mining soil and sawdust with fuel oil by aerated in-vessel composting in the Atacama Region (Chile)
    (ELSEVIER SCIENCE BV, 2008) Godoy Faundez, Alex; Antizar Ladislao, Blanca; Reyes Bozo, Lorenzo; Camano, Andres; Saez Navarrete, Cesar
    Since early 1900s, with the beginning of mining operations and especially in the last decade, small, although repetitive spills of fuel oil had occurred frequently in the Chilean mining desert industry during reparation and maintenance of machinery, as well as casual accidents. Normally, soils and sawdust had been used as cheap readily available sorbent materials of spills of fuel oil, consisting of complex mixtures of aliphatic and aromatic hydrocarbons. Chilean legislation considers these fuel oil contaminated mixtures of soil and sawdust as hazardous wastes, and thus they must be contained. It remains unknown whether it would be feasible to clean-up Chilean desert soils with high salinity and metal content, historically polluted with different commercial fuel oil, and contained during years. Thus, this study evaluated the feasibility of aerated in-vessel composting at a laboratory scale as a bioremediation technology to clean-up contaminated desert mining soils (fuel concentration > 50,000 mg kg(-1)) and sawdust (fuel concentration > 225,000 mg kg(-1)) in the Atacama Region. The composting reactors were operated using live soil to sawdust ratios (S:SD, 1:0, 3:1, 1:1, 1:3, 0: 1, on a dry weight basis) under mesophilic temperatures (30-40 degrees C), constant moisture content (MC, 50%) and continuous aeration (161 min(-1)) during 56 days. Fuel oil concentration and physico-chemical changes in the composting reactors were monitored following standard procedures. The highest (59%) and the lowest (35%) contaminant removals were observed in the contaminated sawdust and contaminated soil reactors after 56 days of treatment, respectively. The S:SD ratio, time of treatment and interaction between both factors had a significant effect (p < 0.050) on the contaminant removal. The results of this research indicate that bioremediation of an aged contaminated mixture of desert mining soil and sawdust with fuel oil is feasible. This study recommends a S:SD ratio 1:3 and a correct nutrient balance in order to achieve a maximum overall hydrocarbon removal of fuel oil in the weathered and aged contaminated wastes. (C) 2007 Elsevier B.V. All rights reserved.
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    Uso de biosólidos como reactivo espumante en procesos de flotación: caracterización física y química
    (2011) Reyes Bozo, Lorenzo; Herrera-Urbina, Ronaldo; Godoy-Faúndez, Alex; Saez Navarrete, Cesar Antonio; Herrera, Miguel; Ginocchio, Rossana
    La flotación espumosa usa diversos reactivos, orgánicos e inorgánicos, para aumentar el rendimiento y selectividad del proceso. La flotación utiliza sustancias tensoactivas que se adsorben en la interfase aire/agua. Como potenciales sustitutos de los espumantes usados actualmente, se consideran los residuos orgánicos de origen animal, como los biosólidos. Este estudio, evalúa el uso de biosólidos y ácidos húmicos como agentes espumantes para fl otación espumosa, cuantifi cándose su capacidad tensoactiva y para formar y estabilizar espumas. Biosólidos son capaces de cambiar la tensión superfi cial de una solución, crear y estabilizar espumas. Dosis menores a 4 g L-1 muestran un afecto tensoactivo mayor comparado con reactivos espumantes, tipo MIBC. Para un uso efectivo de biosólidos, se requiere realizar una etapa de preacondicionamiento, que permita separar la fracción soluble y coloidal que tiene la capacidad tensoactiva. El uso de biosólidos a gran escala necesita investigación adicional para escalar los resultados obtenidos en laboratorio.