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The Big Five personality traits have shown associations with symptoms of depression and anxiety among college students, but it is unclear which factors mediate these relationships. Past research suggests that psychological distress is closely related to difficulties in affect regulation (e.g., low distress tolerance). Therefore, the present study examined the associations between personality traits and depression and anxiety via emotion regulation and distress tolerance. Participants were 694 (81.4% females; Mean age = 23.12 [SD 2.75]) Argentinian college students who completed an online survey examining mental health and personality variables. A sizeable percentage of students endorsed moderate to severe symptoms of depression (45.1%) or anxiety (25.9%). Utilizing path analyses, we found that appraisal, a dimension of distress tolerance, atemporally mediated the association between emotional stability and symptoms of depression/anxiety (i.e., higher levels of emotional stability â higher appraisal distress tolerance â fewer symptoms of depression/anxiety). Further, expressive suppression (a dimension of emotion regulation) significantly mediated the associations between personality traits (i.e., agreeableness and extraversion) and symptoms of depression (higher levels of agreeableness/extraversion â lower use of expressive suppression â fewer symptoms of depression). Taken together, the results suggest that higher levels of emotional stability, extraversion and agreeableness could protect students from the development of symptoms of depression/anxiety via lower maladaptive emotion regulation strategies and higher distress tolerance (particularly appraisal). These findings highlight the relevance of intervention strategies specifically tailored to improve distress tolerance and emotion regulation for those students undergoing mental health problems.
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Ansiedad , Depresión , Regulación Emocional , Personalidad , Humanos , Femenino , Masculino , Depresión/psicología , Ansiedad/psicología , Adulto Joven , Adulto , Estudiantes/psicología , Distrés Psicológico , Encuestas y Cuestionarios , Adolescente , Estrés Psicológico/psicologíaRESUMEN
Malaria remains a highly prevalent infectious disease worldwide, particularly in tropical and subtropical regions. Effectively controlling of mosquitoes transmitting of Plasmodium spp. is crucial in to control this disease. A promising strategy involves utilizing plant-derived products, such as the Neem tree (Azadirachta indica), known for its secondary metabolites with biological activity against various insect groups of agricultural and public health importance. This study investigated the effects of a nanoformulation prototype Neem on factors linked to the vector competence of Anopheles aquasalis, a malaria vector in Latin America. Different concentrations of the nanoformulation were supplied through sugar solution and blood feeding, assessing impacts on longevity, fecundity, fertility, and transgenerational survival from larvae to adults. Additionally, the effects of the Neem nanoformulation and NeemAZAL® formulation on the sporogonic cycle of P. vivax were evaluated. Overall, significant impacts were observed at 100 ppm and 1,000 ppm concentrations on adult survival patterns and on survival of the F1 generation. A trend of reduced oviposition and hatching rates was also noted in nanoformulation-consuming groups, with fertility and fecundity declining proportionally to the concentration. Additionally, a significant decrease in the infection rate and intensity of P. vivax was observed in the 1,000 ppm group, with a mean of 3 oocysts per female compared to the control's 27 oocysts per female. In the commercial formulation, the highest tested concentration of 3 ppm yielded 5.36 oocysts per female. Concerning sporozoite numbers, there was a reduction of 52 % and 87 % at the highest concentrations compared to the control group. In conclusion, these findings suggest that the A. indica nanoformulation is a potential as a tool for malaria control through reduction in the vector longevity and reproductive capacity, possibly leading to decreased vector population densities. Moreover, the nanoformulation interfered with the sporogonic development of P. vivax. However, further basic research on Neem formulations, their effects, and mechanisms of action is imperative to gain a more specific perspective for safe field implementation.
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Anopheles , Azadirachta , Mosquitos Vectores , Plasmodium vivax , Animales , Anopheles/efectos de los fármacos , Anopheles/parasitología , Azadirachta/química , Femenino , Mosquitos Vectores/efectos de los fármacos , Mosquitos Vectores/parasitología , Plasmodium vivax/efectos de los fármacos , Fertilidad/efectos de los fármacos , Extractos Vegetales/farmacología , Extractos Vegetales/química , Extractos Vegetales/administración & dosificación , Larva/efectos de los fármacos , Longevidad/efectos de los fármacos , Control de Mosquitos/métodosRESUMEN
Studies on the impact of the COVID-19 pandemic in sub-Saharan Africa have yielded varying results, although authors universally agree the real burden surpasses reported cases. The primary objective of this study was to determine SARS-CoV-2 seroprevalence among patients attending Monkole Hospital in Kinshasa (D.R. Congo). The secondary objective was to evaluate the analytic performance of two chemiluminescence platforms: Elecsys® (Roche) and VirClia® (Vircell) on dried blood spot samples (DBS). The study population (N = 373) was recruited in two stages: a mid-2021 blood donor cohort (15.5% women) and a mid-2022 women cohort. Crude global seroprevalence was 61% (53.9%-67.8%) pre-Delta in 2021 and 90.2% (84.7%-94.2%) post-Omicron in 2022. Anti-spike (S) antibody levels significantly increased from 53.1 (31.8-131.3) U/mL in 2021 to 436.5 (219.3-950.5) U/mL in 2022 and were significantly higher above 45 years old in the 2022 population. Both platforms showed good analytic performance on DBS samples: sensitivity was 96.8% for IgG (antiN/S) (93.9%-98.5%) and 96.0% (93.0%-98.0%) for anti-S quantification. These results provide additional support for the notion that exposure to SARS-CoV-2 is more widespread than indicated by case-based surveillance and will be able to guide the pandemic response and strategy moving forward. Likewise, this study contributes evidence to the reliability of DBS as a tool for serological testing and diagnosis in resource-limited settings.
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COVID-19 , SARS-CoV-2 , Humanos , Femenino , Persona de Mediana Edad , Masculino , COVID-19/diagnóstico , COVID-19/epidemiología , República Democrática del Congo/epidemiología , Pandemias , Reproducibilidad de los Resultados , Estudios Seroepidemiológicos , Anticuerpos AntiviralesRESUMEN
Dried blood spots (DBSs) are an economical and convenient alternative to serum/plasma, which allow for the serological and molecular study of different pathogens. Sixty-four blood samples were collected by venipuncture and spotted onto Whatman™ 903 cards to evaluate the utility of DBSs and the effect of the storage temperature for 120 days after sample collection to carry out serological diagnosis. Mumps, measles and rubella IgG were investigated from DBSs and plasma using an automated chemiluminescent immunoassay. Using a calculated optimal cut-off value, the serological evaluation of mumps, measles and rubella using DBSs achieved high sensitivity (100%, 100% and 82.5%, respectively) and specificity (100%, 87.5% and 100%, respectively). The correlation observed between the plasma and the DBSs processed after sample collection was high (0.914-0.953) for all antibodies studied, both considering hematocrit before sample elution or not. For the different storage conditions, the correlation with plasma was high at 4 °C (0.889-0.925) and at -20 °C (0.878-0.951) but lower at room temperature (0.762-0.872). Measles IgG results were more affected than other markers when DBSs were stored at any temperature for 120 days. To summarize, hematocrit does not affect the processing of DBSs in the study of serological markers of mumps, measles and rubella. DBS stability for serological diagnosis of mumps and rubella is adequate when samples are stored at -20 °C or 4 °C, but not at room temperature, for a period of 4 months.
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INTRODUCTION: Use of Social networking sites (SNSs) is a highly prevalent behavior worldwide and, for some individuals, its use can turn maladaptive. There has been growing interest to identify which variables are associated with problematic use of SNSs. AIM: The present study cross-sectionally examined whether the associations between different features of self-control (i.e., impulsivity-like traits, self-regulation and emotion regulation) indirectly relate to two outcomes of SNSs (hours of use and problematic use) via distress tolerance. METHODS: A sample of 509 Argentinean college students (70.3% female; Mean age = 21.15 ± 5.15) completed an online survey. RESULTS: Two significant indirect effects were found: a) higher negative urgency was associated with higher problematic use of SNSs via lower distress tolerance and b) higher self-regulation was associated with lower problematic use of SNSs via higher distress tolerance. Positive urgency, negative urgency and self-regulation had significant direct associations with problematic use of SNSs while neither component of emotion regulation was significantly associated with SNSs outcomes. No significant direct or indirect effects were found between any of the self-control features and time spent using SNSs. CONCLUSIONS: The results highlight dysfunctional self-control, particularly emotion-driven impulsivity and low self-regulation, as relevant components of maladaptive SNSs that seem to operate by decreasing the perceived capacity to tolerate negative affect. In this context, interventions targeting the development and improvement of distress tolerance abilities might have a positive impact on problematic use of SNS.
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AIM: To evaluate the serological response against SARS-CoV-2 in a multicenter study representative of the Spanish COVID pandemic. METHODS: IgG and IgM + IgA responses were measured on 1466 samples from 1236 Spanish COVID-19 patients admitted to the hospital, two commercial ELISA kits (Vircell SL, Spain) based on the detection of antibodies against the viral spike protein and nucleoprotein, were used. RESULTS: Approximately half of the patients presented antibodies (56.8% were IgM + IgA positive and 43.0% were IgG positive) as soon as 2 days after the first positive PCR result. Serological test positivity increased with time from the PCR test, and 10 days after the first PCR result, 91.5% and 88.0% of the patients presented IgM + IgA and IgG antibodies, respectively. CONCLUSION: The high values of sensitivity attained in the present study from a relatively early period of time after hospitalization support the use of the evaluated serological assays as supplementary diagnostic tests for the clinical management of COVID-19.
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Anticuerpos Antivirales/sangre , Formación de Anticuerpos , COVID-19/inmunología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Prueba Serológica para COVID-19 , Proteínas de la Nucleocápside de Coronavirus/inmunología , Ensayo de Inmunoadsorción Enzimática , Femenino , Hospitalización , Humanos , Inmunoglobulina A , Inmunoglobulina G , Inmunoglobulina M , Masculino , Persona de Mediana Edad , Fosfoproteínas/inmunología , Sensibilidad y Especificidad , Factores Sexuales , España , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto JovenRESUMEN
Reliable serological tests are required to determine the prevalence of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and to characterize immunity to the disease in order to address key knowledge gaps in the coronavirus disease 2019 (COVID-19) pandemic. Quantitative suspension array technology (qSAT) assays based on the xMAP Luminex platform overcome the limitations of rapid diagnostic tests and enzyme-linked immunosorbent assays (ELISAs) with their higher precision, dynamic range, throughput, miniaturization, cost-efficiency, and multiplexing capacity. We developed three qSAT assays for IgM, IgA, and IgG against a panel of eight SARS-CoV-2 antigens, including spike protein (S), nucleocapsid protein (N), and membrane protein (M) constructs. The assays were optimized to minimize the processing time and maximize the signal-to-noise ratio. We evaluated their performances using 128 prepandemic plasma samples (negative controls) and 104 plasma samples from individuals with SARS-CoV-2 diagnosis (positive controls), of whom 5 were asymptomatic, 51 had mild symptoms, and 48 were hospitalized. Preexisting IgG antibodies recognizing N, M, and S proteins were detected in negative controls, which is suggestive of cross-reactivity to common-cold coronaviruses. The best-performing antibody/antigen signatures had specificities of 100% and sensitivities of 95.78% at ≥14 days and 95.65% at ≥21 days since the onset of symptoms, with areas under the curve (AUCs) of 0.977 and 0.999, respectively. Combining multiple markers as assessed by qSAT assays has the highest efficiency, breadth, and versatility to accurately detect low-level antibody responses for obtaining reliable data on the prevalence of exposure to novel pathogens in a population. Our assays will allow gaining insights into antibody correlates of immunity and their kinetics, required for vaccine development to combat the COVID-19 pandemic.
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Antígenos Virales/inmunología , Prueba Serológica para COVID-19/métodos , COVID-19/diagnóstico , Isotipos de Inmunoglobulinas/sangre , SARS-CoV-2/inmunología , Adulto , Anticuerpos Antivirales/sangre , COVID-19/sangre , Reacciones Cruzadas , Femenino , Humanos , Inmunoensayo , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Proteínas Estructurales Virales/inmunologíaRESUMEN
Advanced oxidation processes (AOPs) constitute a developing area of particular interest for researchers in different fields due to their broad range of applications. However, there are few studies dedicated to the bibliometric analysis of AOPs. Hence, a systematic literature review of research publications (research articles, review articles, and book chapters) from 1980 to 2018 was carried out to visualize and evaluate research trends on AOPs around the world and, especially in Ibero-America (IA), on the field of wastewater treatment. Using the most extensive databases in literature search, Scopus and Web of Science (WoS), which encompass 95% of the publications in the world, a total of 18,751 records were retrieved by limiting the search results to words associated with AOPs in the titles, keyword, and abstracts. Raw data were manually organized and filtered, standardizing authors and institution names, publication titles, and keywords for the purpose of eliminating double-counted entries. Similarly, homonymous authors and institutions were identified for all records retrieved. The bibliometric dataset was processed using the VantagePoint software. The research trends visualized about AOPs were as follows: number of publications per triennium, publications by country, participation by continent, most important journals and authors, most referenced institutions, global network of co-authors, and keywords network visualization, highlighting the Ibero-American contribution to global research.
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Bibliometría , Aguas Residuales , Bases de Datos Factuales , Oxidación-Reducción , Estados UnidosRESUMEN
Risk of developing myelodysplastic syndrome (MDS) is significantly increased in both multiple myeloma (MM) and monoclonal gammopathy of undetermined significance, suggesting that it is therapy independent. However, the incidence and sequelae of dysplastic hematopoiesis at diagnosis are unknown. Here, we used multidimensional flow cytometry (MFC) to prospectively screen for the presence of MDS-associated phenotypic alterations (MDS-PA) in the bone marrow of 285 patients with MM enrolled in the PETHEMA/GEM2012MENOS65 trial (#NCT01916252). We investigated the clinical significance of monocytic MDS-PA in a larger series of 1252 patients enrolled in 4 PETHEMA/GEM protocols. At diagnosis, 33 (11.6%) of 285 cases displayed MDS-PA. Bulk and single-cell-targeted sequencing of MDS recurrently mutated genes in CD34+ progenitors (and dysplastic lineages) from 67 patients revealed clonal hematopoiesis in 13 (50%) of 26 cases with MDS-PA vs 9 (22%) of 41 without MDS-PA; TET2 and NRAS were the most frequently mutated genes. Dynamics of MDS-PA at diagnosis and after autologous transplant were evaluated in 86 of 285 patients and showed that in most cases (69 of 86 [80%]), MDS-PA either persisted or remained absent in patients with or without MDS-PA at diagnosis, respectively. Noteworthy, MDS-associated mutations infrequently emerged after high-dose therapy. Based on MFC profiling, patients with MDS-PA have altered hematopoiesis and T regulatory cell distribution in the tumor microenvironment. Importantly, the presence of monocytic MDS-PA at diagnosis anticipated greater risk of hematologic toxicity and was independently associated with inferior progression-free survival (hazard ratio, 1.5; P = .02) and overall survival (hazard ratio, 1.7; P = .01). This study reveals the biological and clinical significance of dysplastic hematopoiesis in newly diagnosed MM, which can be screened with moderate sensitivity using cost-effective MFC.
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Hematopoyesis Clonal , Mieloma Múltiple/patología , Síndromes Mielodisplásicos/etiología , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Ensayos Clínicos Fase III como Asunto , Terapia Combinada , Femenino , Citometría de Flujo/métodos , Trasplante de Células Madre Hematopoyéticas , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Hibridación Fluorescente in Situ , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/mortalidad , Mieloma Múltiple/terapia , Mutación , Pronóstico , Supervivencia sin Progresión , Estudios Prospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto , Trasplante Autólogo , Microambiente TumoralRESUMEN
The understanding of factors affecting the gut bacterial communities in malaria vectors is essential for the design of vector control interventions, such as those based on a paratransgenic approach. One of the requirements of this method is the availability of bacteria from the mosquito susceptible to culture. Thus, the aim of this study was to evaluate the composition and structure of the culturable gut bacterial communities in field mosquitoes Anopheles albimanus from Colombia, in addition to generate a bacterial collection to further analyze microbial functional activity. Gut bacteria were isolated from An. albimanus larvae and adult mosquitoes collected in localities of the Atlantic and Pacific Coasts. The bacterial isolates were grouped in 28 morphospecies that corresponded to three phyla, three classes, nine families and 14 genera. The larvae guts from San Antero (Atlantic Coast) and Buenaventura (Pacific Coast) shared the genera Bacillus and Lysinibacillus and in adults, Bacillus and Bacillus cereus Group were registered in both localities. Gut bacterial richness was higher in adults from the Pacific with respect to the Atlantic Coast, while larval richness was similar in samples of both coasts. The Shannon index indicated uniformity in morphospecies abundances in both localities. Finally, the characterization of morphospecies from the gut of Anopheles albimanus mosquitoes from Colombia by culture-dependent methods complemented with 16S rRNA gene sequencing allowed the definition, at a finer resolution, of the composition and structure of these microbial communities. In addition, the obtained bacterial culture collection will allow further evaluation of the microorganisms for their potential as biocontrol agents.
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Anopheles/microbiología , Bacterias/crecimiento & desarrollo , Microbioma Gastrointestinal , Algoritmos , Animales , Bacterias/clasificación , Bacterias/aislamiento & purificación , Secuencia de Bases , Teorema de Bayes , Biodiversidad , Colombia , Farmacorresistencia Microbiana , Geografía , Larva/microbiología , Filogenia , ARN Ribosómico 16S/genéticaRESUMEN
We report the first detection of the gravitational lensing of the cosmic microwave background through a measurement of the four-point correlation function in the temperature maps made by the Atacama Cosmology Telescope. We verify our detection by calculating the levels of potential contaminants and performing a number of null tests. The resulting convergence power spectrum at 2° angular scales measures the amplitude of matter density fluctuations on comoving length scales of around 100 Mpc at redshifts around 0.5 to 3. The measured amplitude of the signal agrees with Lambda cold dark matter cosmology predictions. Since the amplitude of the convergence power spectrum scales as the square of the amplitude of the density fluctuations, the 4σ detection of the lensing signal measures the amplitude of density fluctuations to 12%.
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Tipo de Estudio: Descriptivo epidemiológico retrospectivo en 644 pacientes ingresados en la Unidad de quemados del hospital Luis Vernaza período 2003. Objetivos: Ordenar y presentar la información obtenida en el manejo de las quemaduras por electricidad en esta unidad especializada. Resultados: Pacientes de sexo masculino 86.80%, 59.47%, con edades entre 21 y 40 años. El sitio con mayor ocurrencia de accidentes fue el lugar de trabajo con 351 (54.50%) reportes, en el hogar se produjeron 236 (36.65%) casos, 57 (8.85%) en la calle, automóvil, etc. Generalmente los pacientes presentaron quemaduras de II grado con una media de 9.3% de Superficie Corporal Quemada (SCQ). La secuela más importante fue la amputación; 64.3% de éstas se realizaron en miembros superiores. La estancia hospitalaria media fue de 38 días, la mortalidad 3.1%. Conclusiones: La tendencia del número de casos con quemaduras eléctricas atendidos en el hospital Luis Vernaza está elevándose y es importante el grado de discapacidad que producen, lo que puede significar para los sistemas de salud una significativa inversión de recursos.
Type of study: Descriptive, retrospective of 644 patients admitted to the Burn Unit of the Luis Vernaza Hospital period 2003.Objectives: To organize the information obtained in managing electrical burn injuries admitted to the unit.Results:We found that electrical burn injuries were most common in males (86.80%) between the age group of 21-40 (59.47%). Percentage of the most common places of injury was:Place of work 351 (54.50%)Household 236 (36.65%)Street, automobile, etc 57 cases (8.85%)Most of the patients had 2nd degree burns and a mean burn size of 9.3% total body surface area. The most common sequelae were amputation (64.3%) of superior limbs. The mean hospital stay was of 38 days and a mortality of 3.1%.Conclusions: The number of cases of electrical burn injuries admitted at the Hospital Luis Vernaza and rate of disability is increasing.
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Masculino , Adulto , Femenino , Persona de Mediana Edad , Accidentes de Trabajo , Quemaduras por Electricidad , Unidades de Quemados , Fluidoterapia , Riesgos LaboralesRESUMEN
The objective of this article is to evaluate the effect of water depth on organic matter removal efficiency in horizontal subsurface flow constructed wetlands (SSFs). Experiments were carried out in a pilot plant comprising eight parallel SSF of almost equal surface area (54-56 m2 each) and treating urban wastewater. Each SSF differs from the others in the aspect ratio or the size of the granular medium or the water depth. During a period of two years, the shallow SSFs (0.27 m water depth) removed more chemical oxygen demand (COD) (72-81%), biochemical oxygen demand (BOD)5 (72-85%), ammonia (35-56%), and dissolved reactive phosphorus (DRP) (8-23%) than deep SSFs (0.5 m water depth) (59-64% for COD; 51-57% for BOD5; 18-29% for ammonia; and 0-7% for DRP). Experiments carried out during the summer indicated that sulphate reduction accounted for a clearly higher organic matter removal in the deep SSFs than in the shallow ones. Denitrification seemed to be a significant mechanism for organic matter removal to occur in shallow SSFs. The results suggest that the relative contribution of different metabolic pathways varies with depth.
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Ecosistema , Nitrógeno/metabolismo , Eliminación de Residuos Líquidos/métodos , Compuestos Orgánicos , Oxígeno/metabolismo , Fósforo/análisis , Fósforo/química , Plantas , Estaciones del Año , Movimientos del AguaRESUMEN
A pilot-scale horizontal flow constructed wetland (HFCW) system planted with common reed (Phragmites sp.) was constructed to study how hydraulic loading rate (HLR), aspect ratio, water depth, and granular medium affect to the fate of several organic matter degradation intermediates namely, acetic acid (HAc), isovaleric acid (Isoval), and dimethylsulfide (DMS). ANOVA statistical analysis performed on the data set of 8 months of operation shows that the HLR and the water depth are two major factors that control the performance of HFCWs for the target analytes. A clear difference in the HFCW effluent concentrations was obtained according to water depth. Effluents of the shallow water depth contained lower DMS (1.05-1.44 microg l-1), HAc (7.91-10.9 mg l-1), and Isoval (0.11-0.15 mg l-1) concentrations than the deeper beds (DMS: 1.68-2.40 microg l-1; HAc: 9.29-14.4 mg l-1, and Isoval: 0.20-0.31 mg l-1). Such differences could be accounted to the different formation and consumption rates of the organic matter degradation intermediates, which is related with the redox potentials (E). Indeed, it could lead to different biochemical reactions of organic matter degradation according with the E value. HLR has a statistically significant influence on the effluent HAc, Isoval, and DMS concentrations. Seasonal variability of effluent HAc concentration shows that it is independent on the HAc loading. While the loading showed no seasonal pattern, the removal efficiency was clearly higher in cold months, which suggests a predominant internal production of HAc in HFCWs in the warm season from the accumulated organic particulate matter. Similar results were also found when Isoval and DMS were considered.
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Acetatos/análisis , Ácidos Pentanoicos/análisis , Sulfuros/análisis , Eliminación de Residuos Líquidos/métodos , Acetatos/metabolismo , Biodegradación Ambiental , Hemiterpenos , Ácidos Pentanoicos/metabolismo , Poaceae , Sulfuros/metabolismo , Movimientos del AguaRESUMEN
The behavior of linear alkylbenzene sulfonate (LAS) and sulfophenyl carboxylate (SPC) biointermediates in a pilot subsurface flow constructed wetland (SFCW) is reported for the first time. The effects of wetland configuration and operation on their treatment efficiency were investigated. The pilot SFCW constituted by eight beds of 55 m2 with different aspect ratios (1 x 1; 1.5 x 1; 2 x 1; 2.5 x 1), two water depths (i.e., 0.47 and 0.27 cm) at 5 cm below surface and two medium sizes (i.e., D60 = 10 mm and 3.5 mm) planted with Phragmites sp. That SFCW pilottreats urban wastewater (i.e., 200 inhabitants) and was operated at four hydraulic loading rates (HLRs) (20, 27, 36, and 45 mm d(-1)). Influent and effluent sampling was carried out from May 2001 to January 2002 with a weekly pattern. Main results were as follows: (i) water depth has a major influence on the performance of SFCW for the LAS removal, and HLR shows significant effect on SPC evolution; (ii) water temperature has a significant effect on the LAS evolution; (iii) biodegradation of LAS and SPC can occur under sulfate-reducing environment and mixed conditions (i.e., sulfate-reducing and denitrification), but aerobic respiration cannot be excluded; and (iv) C13 LAS homologues were generally removed in higher extent than the shorter alkyl chain counterparts. In the most appropriate conditions, LAS and SPC can be biodegraded up to 71% and 11%, respectively, in the pilot SFCW evaluated.
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Ácidos Alcanesulfónicos/aislamiento & purificación , Tensoactivos/aislamiento & purificación , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Ácidos Alcanesulfónicos/metabolismo , Biodegradación Ambiental , Ecosistema , Poaceae , Tensoactivos/metabolismo , Movimientos del Agua , Contaminantes Químicos del Agua/metabolismoRESUMEN
This study evaluates the effect of hydraulic loading rate (HLR), aspect ratio, granular medium size and water depth on the removal of selected contaminants during the start up of horizontal subsurface flow reed beds (HFRBs). Experiments were carried out in a pilot-scale HFRB system comprising four pairs of lined beds of almost equal surface area (54-56 m(2) each bed), with the following aspect ratios: 1:1, 1.5:1, 2:1 and 2.5:1. The size of the granular medium of each pair varied from coarse granitic gravel ( D(60) = 10mm, C(u) = 1.6) to small granitic gravel (D(60) = 3.5 mm, C(u) = 1.7). The beds of the pair with longest aspect ratio were made shallower (0.27 m) than the rest (0.5m) The system was sampled weekly from May 2001 to January 2002. The results indicate that HLR and water depth are determining factors in the performance of the HFRBs. Beds with a water depth of 0.27 m removed more COD (70-80%), BOD(5) (70-85%), ammonia (40-50%) and dissolved reactive phosphorus (DRP) (10-22%) than beds with a depth of 0.5m (60-65% for COD, 50-60% for BOD(5), 25-30% for ammonia, and 2-10% for DRP). The higher efficiency observed shallower beds was related to their less reducing conditions (average redox potential (E) ranging from -351 to -338 mV) than beds with a depth of 0.5m (-390 to -358 mV). The difference in E status between two bed types seems to lead to differences in the biochemical processes. In fact, denitrification was estimated to be a significant reaction in shallower beds.