Modified diatomites for Fenton-like oxidation of phenol

Raw diatomites were modified by acid or base treatments; addition of Fe or Cu species through the incipient wet impregnation method (IWI) and calcination at 700 °C. Samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM-EDX), Mossbauer spectroscopy, point of zero charge (PZC), pyridine temperature programme desorption (TPD), themogravimetric analysis (TGA) and BET surface area determination. According to characterization results, four samples were selected: simply calcined Diatom (D), iron added (Fe-D), acid treated Fe reimpregnated (H-Fe-D) and copper added (Cu/Fe-D). Materials were tested as catalysts for the peroxidation of phenol solutions (1000 mg/L) in a batch laboratory reactor, at different operating conditions in 5 h tests. D, Fe-D and H-Fe-D samples allowed complete phenol removal under all the operating range studied. At optimum conditions, TOC conversions of 50–55% were obtained. Metal ions added through the IWI procedure resulted more labile than metal present originally. The acidic treatment favored the initiation of the reaction showing a reduction of the induction period at almost neutral initial pH. The Fe-D catalyst exhibited poor performance, lower reactions rates and higher Fe leaching. Conversely, high TOC conversions (80%) were achieved with Cu/Fe-D, however, Cu leaching was excessive (12.7%). D and H-Fe-D samples were used in consecutive runs (up to 20 h) maintaining phenol conversion and TOC reduction. Overall, a good performance was obtained, even comparable to more sophisticated Fe catalysts.Fil: Inchaurrondo, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Ramos, Cinthia Paula. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zerjav, G.. National Institute Of Chemistry; EsloveniaFil: Font, J.. Universitat Rovira I Virgili; EspañaFil: Pintar, A.. National Institute Of Chemistry; EsloveniaFil: Haure, Patricia Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Bacillus subtilis as a bioindicator to estimate pentachlorophenol toxicity and concentration

Pentachlorophenol (PCP) and its sodium salt (Na-PCP) are extremely toxic chemicals responsible for important soil and groundwater pollution, mainly caused by wastes from wood-treatment plants, because chlorinated phenols are widely used as wood preservatives. The methods most commonly used for routine analysis of pesticides such as PCP and Na-PCP are high-performance liquid chromatography (HPLC) and gas chromatography– mass spectroscopy (GC–MS). A variety of rapid biological screening tests using marine organisms, bioluminescent bacteria, and enzymes have also been reported. In this study, rapid biological screening analysis using Bacillus subtilis was developed, to assess the biodegradation of PCP and its by-products in liquid samples. An empirical model is proposed for spectrophotometric analysis of Na-PCP concentration after growth of Bacillus subtilis

Meta-Analysis of the Alzheimer\u27s Disease Human Brain Transcriptome and Functional Dissection in Mouse Models.

We present a consensus atlas of the human brain transcriptome in Alzheimer\u27s disease (AD), based on meta-analysis of differential gene expression in 2,114 postmortem samples. We discover 30 brain coexpression modules from seven regions as the major source of AD transcriptional perturbations. We next examine overlap with 251 brain differentially expressed gene sets from mouse models of AD and other neurodegenerative disorders. Human-mouse overlaps highlight responses to amyloid versus tau pathology and reveal age- and sex-dependent expression signatures for disease progression. Human coexpression modules enriched for neuronal and/or microglial genes broadly overlap with mouse models of AD, Huntington\u27s disease, amyotrophic lateral sclerosis, and aging. Other human coexpression modules, including those implicated in proteostasis, are not activated in AD models but rather following other, unexpected genetic manipulations. Our results comprise a cross-species resource, highlighting transcriptional networks altered by human brain pathophysiology and identifying correspondences with mouse models for AD preclinical studies

Sediment dynamics in a turbidity maximum located in the Atlantic French coast near the Loire estuary mouth

Poste

Plasticity in resource allocation based life history traits in the Pacific oyster, Crassostrea gigas. I. Spatial variation in food abundance

We investigated the quantitative genetics of plasticity in resource allocation between survival, growth and reproductive effort in Crassostrea gigas when food abundance varies spatially. Resource allocation shifted from survival to growth and reproductive effort as food abundance increased. An optimality model suggests that this plastic shift may be adaptive. Reproductive effort plasticity and mean survival were highly heritable, whereas for growth, both mean and plasticity had low heritability. The genetic correlations between reproductive effort and both survival and growth were negative in poor treatments, suggesting trade-offs, but positive in rich ones. These sign reversals may reflect genetic variability in resource acquisition, which would only be expressed when food is abundant. Finally, we found positive genetic correlations between reproductive effort plasticity and both growth and survival means. The latter may reflect adaptation of C. gigas to differential sensitivity of fitness to survival, such that genetic variability in survival mean might support genetic variability in reproductive effort plasticity

Bacillus subtilis as a bioindicator for estimating pentachlorophenol toxicity and concentration

Pentachlorophenol (PCP) and its sodium salt (Na-PCP) are extremely toxic chemicals responsible forimportant soil and groundwater pollution, mainly caused by wastes from wood-treatment plants, because chlorinated phenols are widely used as wood preservatives. The methods most commonly used for routine analysis of pesticides such as PCP and Na-PCP are high-performance liquid chromatography (HPLC) and gas chromatography– mass spectroscopy (GC–MS). A variety of rapid biological screening tests using marine organisms, bioluminescent bacteria, and enzymes have also been reported. In this study, rapid biological screening analysis using Bacillus subtilis was developed, to assess the biodegradation of PCP and its by-products in liquid samples. An empirical model is proposed for spectrophotometric analysis of Na-PCP concentration after growth of Bacillus subtilis.Fil: Ayude, María Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Okada, Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Ingeniería Bioquímica; ArgentinaFil: González, J. F.. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Ingeniería Bioquímica; ArgentinaFil: Haure, Patricia Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Murialdo, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Ingeniería Bioquímica; Argentin

Dryout phenomenon in the periodic operation of a trickle bed reactor

Periodic operation was investigated for the hydrogenation of aplpha-methylsyrene to cumene over 0.5% Pd on alumina spheres. The effect of several variables such as gas flow rate, gas and liquid composition, and liquid feed temperature on unsteady-state liquid flow modulation in a Trickle Bed Reactors is studied. These parameters affect the depletion time of the volatile reactant as well as the temperature profiles of the dry cycle. A criterion is presented that allows for an estimation of the maximum temperature during the dry cycle based on mass and energy balances.Fil: Ochoa, J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Cechini, Jorge Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Haure, Patricia Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Nanofiltration of partial oxidation products and copper from catalyzed wet peroxidation of phenol

The aim of this work is to study the combination of Catalytic Wet Peroxide Oxidation (CWPO) and nanofiltration processes in the treatment of phenol solutions. A home-made Cu-chitosan/Al2O3 catalyst was applied for this purpose. The effluent from CWPO usually contains some metal leached from the catalyst in addition to latter oxidation intermediates (short chain organic acids). Downstream nanofiltration is used to retain the metal leached from the catalyst, which would result in secondary pollution and negatively impact on a possible subsequent biological treatment step. The CWPO was performed in a batch recycle trickle bed reactor packed with the catalyst. The final distribution of intermediates was identified by HPLC. Cross flow filtration experiments using either model solutions containing phenol and the main intermediates (succinic, malonic, maleic and oxalic acid), with and without Cu(II) or the effluent of the CWPO reaction were performed using a NF90 membrane. When all intermediates were combined, the rejection of copper reached over 95% while an acceptable maximum of 10% of permeate flux loss, compared with the initial flux, was maintained. Nanofiltration of a real CWPO effluent gave a higher copper recovery of 97%. Thus, the permeate toxicity was highly reduced. In addition, after 4 h of filtration, only a 5% of flux loss was observed, which guarantees a stable filtration for days.Fil: Inchaurrondo, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina; Universidad Nacional de Mar del Plata. Facultad de Ingenieria; Argentina;Fil: Font, J.. Universitat Rovira I Virgili; España;Fil: Haure, Patricia Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina; Universidad Nacional de Mar del Plata. Facultad de Ingenieria; Argentina