articles+ search results

MINES & mineral resources, RAMAN spectroscopy, INDUCTIVELY coupled plasma atomic emission spectrometry, ADSORPTION, and LANGMUIR isotherms

In Colombia, a mineral rich in MnO2 is extracted from the mines of Mallama, Narifio. In this work we studied the adsorption capacity of this mineral for Fe(II) dissolved in aqueous solution of open systems. The characterization was done through ICP-AES, XRF and Raman spectroscopy. The effect of different pretreatments on the mineral with oxidizing agents such as KMnO4 and NaOCl was evaluated. Studies of equilibrium and kinetics of adsorption showed that the mechanism fits well to the Langmuir isotherm and its kinetics to a model of pseudo-second order. At the conditions studied was found that the adsorption capacity for the mineral modified with KMnO4 and NaOCl were 59.209 and 51.279 mg/g respectively. It is concluded that the mineral is a potential alternative in water treatment. [ABSTRACT FROM AUTHOR]

Ecology, Ecologie, Environment, Environnement, Geology, Géologie, Pollution, Toxicology, Toxicologie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Pollution, Pollution du sol et des sédiments, Soil and sediments pollution, Propriétés biologiques et physicochimiques des polluants. Interaction dans le sol, Biological and physicochemical properties of pollutants. Interaction in the soil, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Géologie de l'ingénieur et de l'environnement. Géothermie, Engineering and environment geology. Geothermics, Pollution, géologie de l'environnement, Pollution, environment geology, Composé organique, Organic compounds, Compuesto orgánico, Activité microbienne, Microbial activity, Actividad microbiana, Argile, Clay, Arcilla, Caractéristique sol, Property of soil, Característica suelo, Cinétique, Kinetics, Cinética, Composé aromatique polycyclique, Polycyclic aromatic compound, Compuesto aromático policíclico, Devenir polluant, Pollutant behavior, Evolución contaminante, Dégradation biologique, Biodegradation, Degradación biológica, Désorption, Desorption, Desorción, Hydrocarbure, Hydrocarbon, Hidrocarburo, Interaction sol, Soil interaction, Interacción suelo, Matière organique, Organic matter, Materia orgánica, Pollution sol, Soil pollution, Polución suelo, Pyrène, Pyrene, Pireno, Smectite, Esmectita, Sol limoneux fin, Silt loam soil, Suelo franco limoso, Sol sableux argileux, Sandy clay loam soil, Suelo franco arcilloso arenoso, Sol sableux loameux, Sandy loam soil, Suelo franco arenoso, Vermiculite, Vermiculita, Matière dissoute, and Dissolved matter

Desorption and biodegradation of pyrene (PYR) were investigated and their relationships to soil characteristics were addressed. The results indicated that maximum achievable desorption was 30.2, 10.4, and 1.0 mg/kg for soils that had 1.7, 2.2, and 4.4 wt.% of expandable clays (smectite and vermiculite), respectively. Neither dissolved organic matter (DOM) nor total clay amounts made a good prediction of the desorption trend. Subsequently, the ease of desorption facilitated a faster aqueous biodegradation rate. The slowest aqueous biodegradation rate, 0.02 l/h, was achieved for the soil system that had the greatest amount of expandable clays, whereas the soil containing 1.7% expandable clays only achieved 0.73 l/h. The soil with 2.2% expandable clays depicted 0.41 l/h of aqueous biodegradation rate. A good linear correlation was obtained between maximum achievable desorption and aqueous biodegradation rate (R2=0.92). Soil analysis revealed that the total (soil+water) biodegradation reached was 65%, 78.3%, and 81.8% of the initial concentration (100 mg/kg) for the sandy clay loam (Colombian), sandy loam (Ohio), and silty loam (New Mexico) soils, respectively. This biodegradation extent was also in good agreement of expandable clay amount. Although aqueous PYR bioavailability was limited due to the strong association with the expandable clays, microbial movement and adhesion to those clays seemed to result in a great extent of the soil-phase biodegradation.

General biology, Biologie générale, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Invertebres, Invertebrates, Echinodermata, Echinodermata, Echinoidea, Invertebrata, Age, Edad, Appareil génital, Genital system, Aparato genital, Cinétique, Kinetics, Cinética, Dilution, Dilución, Fécondation, Fecundation, Fecundación, Gamète, Gamete, Gameto, Milieu marin, Marine environment, Medio marino, Oeuf, Egg, Huevo, Reproduction, Reproducción, Spermatozoïde, Spermatozoa, Espermatozoide, and Strongylocentrotus franciscanus