Juan Salas
Universidad de Granada, Inorganic Chemistry, Faculty Member
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Trans-[Co(en)2(Cl2)]Cl reacts with sodium thiosulphate in a 2 : 1 stoichiometric ratio in water to give the unexpected green product [trans-Co(en)2Cl2][trans-Co(en)2(S2O3)2] green in almost quantitative yield. This represents the first... more
Trans-[Co(en)2(Cl2)]Cl reacts with sodium thiosulphate in a 2 : 1 stoichiometric ratio in water to give the unexpected green product [trans-Co(en)2Cl2][trans-Co(en)2(S2O3)2] green in almost quantitative yield. This represents the first salt containing [trans-Co(en)2(S2O3)2]. The complex salt crystallizes and is triclinic, space group , with a = 6.3067(4), b = 7.7820(5), c = 12.7658(8) Å, α = 100.043(1), β = 91.562(1), γ = 107.339(1)°, Z = 1, V = 586.80(6) Å. The structure was refined to R1 = 0.0199 and wR2 = 0.0537.
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METs technologies can successfully be adapted to vertical flow constructed wetlands, both up-flow and down-flow ones. • Despite of the initial idea that anaerobic conditions were indispensable for MET processes, it has been demonstrated... more
METs technologies can successfully be adapted to vertical flow constructed wetlands, both up-flow and down-flow ones. • Despite of the initial idea that anaerobic conditions were indispensable for MET processes, it has been demonstrated that the best performance is obtained for the down-flow METV-filter, where aerobic conditions are imposed. • METV-filters (up and down-flow) present larger organic matter removal rates than simple gravel and sand filters, although differences are not notorious for the organic loads applied in this study.
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We propose a probabilistic framework for estimating the return period of extreme events such as annual maximum floods and low flows. Traditional approaches of frequency analysis assume that the underlying flow data are independent and... more
We propose a probabilistic framework for estimating the return period of extreme events such as annual maximum floods and low flows. Traditional approaches of frequency analysis assume that the underlying flow data are independent and identically distributed (\textit{iid}), although this assumption may not always be valid. In fact, in many cases extreme hydrologic data may be autocorrelated and may appear
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The oligonucleotide d(TX)9 , which consists of an octadecamer sequence with alternating non-canonical 7-deazaadenine (X) and canonical thymine (T) as the nucleobases, was synthesized and shown to hybridize into double-stranded DNA through... more
The oligonucleotide d(TX)9 , which consists of an octadecamer sequence with alternating non-canonical 7-deazaadenine (X) and canonical thymine (T) as the nucleobases, was synthesized and shown to hybridize into double-stranded DNA through the formation of hydrogen-bonded Watson-Crick base pairs. dsDNA with metal-mediated base pairs was then obtained by selectively replacing W-C hydrogen bonds by coordination bonds to central silver(I) ions. The oligonucleotide I adopts a duplex structure in the absence of Ag(+) ions, and its stability is significantly enhanced in the presence of Ag(+) ions while its double-helix structure is retained. Temperature-dependent UV spectroscopy, circular dichroism spectroscopy, and ESI mass spectrometry were used to confirm the selective formation of the silver(I)-mediated base pairs. This strategy could become useful for preparing stable metallo-DNA-based nanostructures.
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The combination of Microbial Electrochemical Technologies (METs) and constructed wetlands (CWs) has been satisfactory implemented in previous works leading to a hybrid technology so-called METland. Practically 100% of those works are... more
The combination of Microbial Electrochemical Technologies (METs) and constructed wetlands (CWs) has been satisfactory implemented in previous works leading to a hybrid technology so-called METland. Practically 100% of those works are based in subsurface horizontal flow constructed wetlands of which internal redox gradient meets the optimum conditions for the development of electrochemical processes. On the contrary, no references are found for vertical flow (VF) METlands. Among other benefits, conventional VF CWs have lower surface requirements and do not suffer from clogging problems, quite typical in horizontal flow (HF) ones. However, the prevailing aerobic conditions inside the filtering bed could suppose a restriction to the application of METs. The main goal of this study is to assess the potential use of METs in VF biofilters, adapting their configuration and operating conditions to maximize the synergist effects of both technologies. For that purpose, 4 lab-scale biofilters ...
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The aim of the present work was the assessment of economic and environmental aspects of decentralized energy-saving wastewater treatment systems. The formulated investment and operation cost functions were adjusted by a power law... more
The aim of the present work was the assessment of economic and environmental aspects of decentralized energy-saving wastewater treatment systems. The formulated investment and operation cost functions were adjusted by a power law function. The different wastewater systems serving population settlements between 50 p.e. and 250 p.e., presented associated investment costs varying from €400/p.e. to €200/p.e. and annual operation costs in the range of €70/p.e.– €20/ p.e., respectively. A life cycle analysis approach was used to compare the environmental impact of alternative wastewater treatment systems. The assessment was focused on two energy-saving systems (constructed wetland and slow rate infiltration) and a conventional one (activated sludge process). Low environmental impact of energy-saving wastewater treatment systems was demonstrated, being the most relevant the global warming indicator. Options for reduction of life cycle impacts were assessed including materials used in const...
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El empleo de Humedales Artificiales para la estabilización-deshidratación de los fangos está ampliamente extendido en Dinamarca, EEUU, Francia, Reino Unido y Bélgica. En el caso de España, sólo existen algunas experiencias en Cataluña.... more
El empleo de Humedales Artificiales para la estabilización-deshidratación de los fangos está ampliamente extendido en Dinamarca, EEUU, Francia, Reino Unido y Bélgica. En el caso de España, sólo existen algunas experiencias en Cataluña. Estos sistemas presentan una serie de ventajas con respecto a las eras de secado tradicionales ya que, además de la deshidratación de los fangos, la transferencia de oxígeno entre las capas de grava a través de las raíces de las plantas, favorece la mineralización e higienización del fango. Asimismo, el producto final obtenido puede ser empleado en agricultura. No obstante, durante el proceso de secado de fangos se genera un lixiviado que, por lo general, es devuelto a cabecera de la planta depuradora para su tratamiento. En este trabajo se ha procedido a la caracterización de dicho permeado a fin de conocer su composición y analizar posibles mejoras en el proceso de deshidratación de fangos para disminuir su impacto ambiental. Para ello, se ha emplea...
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This presentation summarizes work done to generate synthetic flow series for the Great Lakes - St. Lawrence River System. Their special hydrological characteristics, the major modeling hypothesis and retained strategies, and a statistical... more
This presentation summarizes work done to generate synthetic flow series for the Great Lakes - St. Lawrence River System. Their special hydrological characteristics, the major modeling hypothesis and retained strategies, and a statistical description of the final synthetic NBS and flow series are each described.
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Guía desarrollada dentro del proyecto ICREW, del Programa Interreg IIIB Espacio Atlántico.
The system formed between bismuth(III) ion and d-gluconic acid was potentiometrically studied in aqueous solution. Measurements were carried out at 20.0 and 25.0±0.1°C and the ionic strength was maintained at 0.100 M with NaNO3. The... more
The system formed between bismuth(III) ion and d-gluconic acid was potentiometrically studied in aqueous solution. Measurements were carried out at 20.0 and 25.0±0.1°C and the ionic strength was maintained at 0.100 M with NaNO3. The potentiometric curves showed the release of four protons in addition to the carboxylic one, leading to the formation of complexes with different degrees of deprotonation. Since the first chelate was completely formed at low pH, competition equilibria involving ethylenediaminetetraacetic acid or nitrilotriacetic acid ligands were used to calculate the corresponding equilibrium constant. Coordination bonding sites for metal–ligand interactions were inferred from 13C NMR spectroscopy. According to the obtained results, the complex formed at acid pH would present a carboxylate coordination and those formed at high pH would involved a bonding with the oxygens of carbons 2, 3, 4 and 5. On the other hand, the complex Bi(C6H9O7)·H2O was isolated and characterize...
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INTRODUCTION Horizontal subsurface flow constructed wetlands have been used as a low cost alternative for wastewater disposal and treatment. They have been proved to be efficient in removing the pollutants of concern like nitrogen,... more
INTRODUCTION Horizontal subsurface flow constructed wetlands have been used as a low cost alternative for wastewater disposal and treatment. They have been proved to be efficient in removing the pollutants of concern like nitrogen, phosphorous, organic matters (Jenssen and Siegrist, 1990) and pathogens (Vega et al., 2003). However, their efficiency in terms of pollutant removal may potentially be reduced because of clogging of the porous medium, which in turn produces chain effects such as reduced hydraulic conductivity, porosity, oxygen supply and increased dispersion (Garcia et al., 2004; Tanner and Sukias, 1995; Tanner et al., 1998; Vandevivre and Baveye, 1992). In regional operation and maintenance analyses, clogging is the worst operational problem of this kind of systems (Rousseau et al., 2004). The exact mechanisms of clogging in constructed wetlands is still unclear, however, it is believed that accumulation of organic and inorganic solids, biofilm growth, chemical precipita...
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Los objetivos generales de la Tesis se centraron en: - Mejorar el comportamiento de los Filtros de Turba como tecnología de tratamiento. - Evaluar empleos alternativos de los Filtros de Turba en el proceso global de tratamiento de las... more
Los objetivos generales de la Tesis se centraron en: - Mejorar el comportamiento de los Filtros de Turba como tecnología de tratamiento. - Evaluar empleos alternativos de los Filtros de Turba en el proceso global de tratamiento de las aguas residuales urbanas
ABSTRACT Abstract The reactivities of cobalt(II) and manganese(II) salts towards HDMV (N,N´-dimethylvioluric acid monohydrate) were studied. Reaction of cobalt(II) chloride hexahydrate with HDMV in water-methanol medium at pH=8.0 led to... more
ABSTRACT Abstract The reactivities of cobalt(II) and manganese(II) salts towards HDMV (N,N´-dimethylvioluric acid monohydrate) were studied. Reaction of cobalt(II) chloride hexahydrate with HDMV in water-methanol medium at pH=8.0 led to the formation of a cobalt(III) complex [CoIII(DMV)3].0.5H2O (1), whereas the interaction of manganese(II) chloride tetrahydrate with HDMV under similar reaction conditions afforded [MnII(H2O)6](DMV)2 (2). Dimethylviolurate anion behaves as a bidentate ligand in 1 and counteranion in 2. Both compounds were characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy, cyclic voltammetry and thermogravimetric analysis. Presence of Co(III) in 1 indicates the aerial oxidation of the cobalt(II) precursor. In 1, Co(III) adopts a distorted octahedral [CoN3O3] coordination environment through bonding to the three dimethylviolurato anions. In 2, the [Mn(H2O)6]2+ cations and (DMV)– anions are assembled by multiple hydrogen bonds into a complex 3D H-bonded network. It was analyzed from the topological viewpoint, disclosing a binodal 4,8-connected underlying net with the flu (fluorite) topology. Electrochemical studies reveal that the compounds undergo a quasi-reversible one electron metal centered redox process. DFT studies were carried out to analyse the supramolecular assemblies in the solid state structures, especially lone pair(lp)–π interactions in 1 and H-bonding network in 2.
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INTRODUCTION Constructed wetlands technology (Kadlec and Knight, 1996) is a cost-effective and environmentally friendly method used worldwide to treat wastewaters of different origins. Treatment wetlands improve water quality through... more
INTRODUCTION Constructed wetlands technology (Kadlec and Knight, 1996) is a cost-effective and environmentally friendly method used worldwide to treat wastewaters of different origins. Treatment wetlands improve water quality through removal of suspended solids, organics, nutrients, pathogens (bacteria, parasites, viruses) and metals (Matoszewski, P. et al., 2006). The Experimental Plant of Carrión de los Céspedes (PECC), in Seville, Spain, has been working on the development and implementation of technologies for wastewater treatment in small settlements, since 1990. In an area of 35,000 m 2 , are represented different kinds both extensive and intensive technologies and the constructed wetlands are notably favoured, given that six wetlands, with a total surface of 1,500 m 2 , are built. The different existing modalities are represented: surface flow, horizontal subsurface flow and vertical subsurface flow constructed wetlands, which have been built with different medium thicknesses...
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En este tercer Capítulo del Manual de Tecnologías no Convencionales para la depuración de aguas residuales se describe la tecnología de Lagunaje, abordándose: Fundamentos, Esquemas de funcionamiento, Tipos de lagunas, Mecanismos de... more
En este tercer Capítulo del Manual de Tecnologías no Convencionales para la depuración de aguas residuales se describe la tecnología de Lagunaje, abordándose: Fundamentos, Esquemas de funcionamiento, Tipos de lagunas, Mecanismos de depuración, Microbiología, Rendimientos, Diseño, Construcción, Mantenimiento y explotación y se efectua una revisión del Lagunaje en Andalucía