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1.
Bioengineering (Basel) ; 11(3)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38534498

RESUMO

There are considerable gaps in our understanding of the relationship between human brain activity measured at different temporal and spatial scales. Here, electrocorticography (ECoG) measures were used to predict functional MRI changes in the sensorimotor cortex in two brain states: at rest and during motor performance. The specificity of this relationship to spatial co-localisation of the two signals was also investigated. We acquired simultaneous ECoG-fMRI in the sensorimotor cortex of three patients with epilepsy. During motor activity, high gamma power was the only frequency band where the electrophysiological response was co-localised with fMRI measures across all subjects. The best model of fMRI changes across states was its principal components, a parsimonious description of the entire ECoG spectrogram. This model performed much better than any others that were based either on the classical frequency bands or on summary measures of cross-spectral changes. The region-specific fMRI signal is reflected in spatially and spectrally distributed EEG activity.

2.
J Hazard Mater ; 437: 129319, 2022 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-35897170

RESUMO

Novel powdered activated carbons (PACs) from pine cones and pine nut shells (PNSs) were tested for the competitive adsorption of pharmaceutical compounds (PhCs) in spiked (100 µg/L) secondary effluent and mixed liquor from an urban wastewater treatment plant. Steam activated PNS77, with hierarchical pore structure and 1463 m2/g of BET area, outperformed the commercial benchmark (WP220, mineral origin) for PhCs and dissolved organic matter (DOM) control. PNS77 attained the highest adsorption capacity and rate in synthetic and real wastewaters. Competitive adsorption isotherms revealed the detrimental effect of direct site competing DOM on PhC removal. The PhCs' adsorbability increased with their hydrophobicity, regardless of the water matrix. Kinetic data allowed inferring that indirect competition due to pore constriction/blockage appeared to occur only in mixed liquor. Adsorption isotherm data modelling for ng/L range revealed 80 % removal of carbamazepine and diclofenac would be achieved dosing 8-15 mg/L PNS77 to secondary effluent, while for mixed liquor the dose must be doubled to balance the increased competition. Hydrophilic sulfamethoxazole required a higher dose (34-44 mg/L), lower in the mixed liquor. PNS77 hierarchical pore network and basic surface chemistry minimized DOM direct site competition, requiring lower doses in practical applications for wastewater treatment.


Assuntos
Resíduos de Drogas , Poluentes Químicos da Água , Purificação da Água , Adsorção , Carvão Vegetal/química , Matéria Orgânica Dissolvida , Resíduos de Drogas/isolamento & purificação , Nozes/química , Poluentes Químicos da Água/química
3.
Environ Res ; 208: 112632, 2022 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-35074358

RESUMO

Twenty-four pharmaceutical active compounds (PhACs) were evaluated in the soft tissues of clams Ruditappes decussatus exposed along a 1.5-km dispersal gradient of the treated effluent from an urban wastewater treatment plant discharging in Ria Formosa, and compared with those in the marine waters and discharged effluents. The clams were exposed for 1 month, in June-July 2016, 2017 and 2018. PhACs were quantified by high performance liquid chromatography coupled to tandem mass spectrometry after the quick, easy, cheap, effective, rugged and safe (QuEChERS) method (clams) or solid-phase extraction (water samples). The most representative PhACs in the effluents and receiving waters (regardless of the tidal dilution effect) were diclofenac, carbamazepine and caffeine (on average ≤ 2 µg/L) and only caffeine exhibited significant inter-annual differences, with higher values in 2017. In turn, the most bioaccumulated PhACs in clams were caffeine (0.54-27 ng/g wet weight, significantly higher in 2016) and acetaminophen (0.37-3.7 ng/g wet weight, significant lower in 2016). A multivariate principal component analysis showed (i) PhAC bioaccumulation primarily depended on biotic factors (clams length and weight), (ii) PhAC physicochemical properties Log Kow, pKa and water solubility interplaying with water abiotic variables were more relevant for explaining data variability in water than the physical dilution/tidal mixing, (iii) this process, reflected by the salinity gradient, had a tertiary role in data variation, responsible for spatial discrimination of marine waters. This study provides a better understanding of PhACs bioaccumulation by clams Ruditapes decussatus in real environmental conditions, under the influence of urban treated effluent dispersal in Ria Formosa coastal lagoon, a major producer of bivalves, ultimately disentangling key factors of PhAC bioaccumulation.


Assuntos
Bivalves , Poluentes Químicos da Água , Purificação da Água , Animais , Bioacumulação , Monitoramento Ambiental/métodos , Preparações Farmacêuticas , Poluentes Químicos da Água/análise
4.
Nanomaterials (Basel) ; 11(11)2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34835780

RESUMO

TiO2-containing photocatalysts, which combine TiO2 with carbon-based materials, are promising materials for wastewater treatment due to synergistic photodegradation and adsorption phenomena. In this work, TiO2/AC composites were produced by the in situ immobilization of TiO2 nanoparticles over activated carbon (AC) derived from spent coffee grains, using different TiO2/AC proportions. The TiO2/AC composites were tested as adsorbents (dark) and as photocatalysts in a combined adsorption+photocatalytic process (solar irradiation) for methylene blue (MB) removal from ultrapure water, and from a secondary effluent (SecEf) of an urban wastewater treatment plant. All the materials were characterized by XRD (X-ray powder diffraction), N2 adsorption-desorption isotherms at -196 °C, SEM (scanning electron microscopy), UV-Vis diffuse reflectance, FTIR (Fourier-transform infrared spectroscopy), TPD (temperature programmed desorption), XPS (X-ray photoelectron spectroscopy) and TGA (thermogravimetric analysis). The TiAC60 (60% C) composite presented the lowest band gap (1.84 eV), while, for TiAC29 (29% C), the value was close to that of bare TiO2 (3.18 vs. 3.17 eV). Regardless of the material, the solar irradiation improved the percentage of MB discolouration when compared to adsorption in dark conditions. In the case of simultaneous adsorption+photocatalytic assays performed in ultrapure water, TiAC29 presented the fastest MB removal. Nevertheless, both TiAC29 and TiAC60 led to excellent MB removal percentages (96.1-98.1%). UV-induced photoregeneration was a promising strategy to recover the adsorption capacity of the materials, especially for TiAC60 and AC (>95%). When the assays were performed in SecEf, all the materials promoted discolouration percentages close to those obtained in ultrapure water. The bulk water parameters revealed that TiAC60 allowed the removal of a higher amount of MB, associated with the overall improvement of the SecEf quality.

5.
Microorganisms ; 9(3)2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33799747

RESUMO

Wastewater treatment plants (WWTPs) are significant reservoirs of bacterial resistance. This work aims to identify the determinants of resistance produced by Gram-negative bacteria in the influent and effluent of two WWTPs in Portugal. A total of 96 wastewater samples were obtained between 2016 and 2019. The numbers of total aerobic and fecal contamination bacteria were evaluated, and genomic features were searched by polymerase chain reaction (PCR) and Next-Generation Sequencing (NGS). Enterobacteriaceae corresponded to 78.6% (n = 161) of the 205 isolates identified by 16sRNA. The most frequent isolates were Escherichia spp. (57.1%, n = 117), followed by Aeromonas spp. (16.1%, n = 33) and Klebsiella spp. (12.7%, n = 26). The remaining 29 isolates (14.1%) were distributed across 10 different genera. Among the 183 resistant genes detected, 54 isolates produced extended spectrum ß-lactamases (ESBL), of which blaCTX-M-15 was predominant (37 isolates; 68.5%). A KPC-3 carbapenemase-producing K. oxytoca was identified (n = 1), with blaKPC-3 included in a transposon Tn4401 isoform b. A higher number of virulence genes (VG) (19 genes) was found in the E. coli 5301 (O25b-ST131-B2) isolate compared with a commensal E. coli 5281 (O25b-ST410-A) (six genes). Both shared five VG [Enterobactin; Aerobactin, CFA/1 (clade α); Type1 (clade γ1); Type IV]. In conclusion, this work highlights the role of relevant clinical bacteria in WWTPs, such as KPC-3-producing K. oxytoca, and, for the first time, a CTX-M-15-producing Ochromobactrum intermedium, a human opportunistic pathogen, and a SED-1-producing Citrobacter farmeri, an uncommon CTX-M-type extended-spectrum beta-lactamase.

6.
Membranes (Basel) ; 11(2)2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33514022

RESUMO

Pressurized powdered activated carbon/coagulation/ceramic microfiltration (PAC/Alum/MF) was investigated at pilot scale for treating low turbidity and low natural organic matter (NOM) surface waters spiked with organic microcontaminants. A total of 11 trials with clarified or non-clarified waters spiked with pesticides, pharmaceutical compounds, or microcystins were conducted to assess the removal of microcontaminants, NOM (as 254 nm absorbance, A254, and dissolved organic carbon, DOC), trihalomethane formation potential (THMFP), aerobic endospores as protozoan (oo)cysts indicators, bacteriophages as viruses indicators, and regular drinking water quality parameters. PAC/(Alum)/MF achieved 75% to complete removal of total microcontaminants with 4-18 mg/L of a mesoporous PAC and 2 h contact time, with a reliable particle separation (turbidity < 0.03 NTU) and low aluminium residuals. Microcontaminants showed different amenabilities to PAC adsorption, depending on their charge, hydrophobicity (Log Kow), polar surface area and aromatic rings count. Compounds less amenable to adsorption showed higher vulnerability to NOM competition (higher A254 waters), greatly benefiting from DOC-normalized PAC dose increase. PAC/Alum/MF also attained 29-47% NOM median removal, decreasing THMFP by 26%. PAC complemented NOM removal by coagulation (+15-19%), though with no substantial improvement towards THMFP and membrane fouling. Furthermore, PAC/Alum/MF was a full barrier against aerobic endospores, and PAC dosing was crucial for ≥1.1-log reduction in bacteriophages.

7.
Membranes (Basel) ; 11(2)2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33498247

RESUMO

Two pilot trials of powdered activated carbon (PAC)/(coagulation)/ceramic microfiltration were conducted to compare continuous 10-12 mg/L PAC inline dosing with 8-10 mg/L dosing to a 2 h-contact tank. Two low turbidity/low natural organic matter (NOM, total organic carbon <2 mg C/L) surface waters spiked with 7.2-10.3 µg/L total-pesticides were tested and the dosing options were compared towards operational performance, average removal of pesticides and NOM and costs. Removal differences between the two PAC dosing options depended on pesticides' amenability to adsorption and NOM characteristics (254 nm absorbance, A254). Waters containing low A254-absorbing NOM and only pesticides amenable to adsorption showed very high removals (all pesticides ≥93%) and no significant differences between the two PAC dosing options. Waters containing higher A254-absorbing NOM and high loads of pesticides less amenable to adsorption (dimethoate, bentazone) required higher inline PAC dose. Those or more severe conditions may require PAC doses higher than tested to comply with the Drinking Water Directive limits for pesticides. Cost analysis showed PAC inline dosing is more cost-effective than PAC dosing to the contact tank when identical PAC dose is sufficient or when the doses are low, even if 50% higher for inline dosing, and the plant is small.

8.
Rev. bras. educ. espec ; 26(4): 689-710, out.-dez. 2020. tab, graf
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1144041

RESUMO

RESUMO: A área de investigação do turismo acessível (TA) apresenta uma tendência de crescimento. Contudo, a maioria dos estudos foca-se na acessibilidade física, havendo poucos que analisem as atitudes dos estudantes e profissionais desse setor relativamente às pessoas com deficiência (PcD). Assim sendo, esta revisão tem como objetivo analisar os trabalhos efetuados em outras áreas científicas sobre as atitudes relativamente às PcD. Pretende-se mapear metodologias, instrumentos de medição e principais variáveis e fatores associados às atitudes, para promover a sua inclusão na sociedade. Realizaram-se pesquisas na Scopus, tendo-se obtido 492 registos. Destes, foram selecionados 96 artigos para análise. Os resultados evidenciam que a avaliação das atitudes relativamente às PcD é uma temática de grande relevância em várias áreas científicas. Os estudos utilizam diversos instrumentos para medir essas atitudes. As experiências anteriores, qualidade e frequência do contato com PcD e conhecimento acerca da deficiência têm influência nas atitudes. Contudo, os resultados divergem na influência do perfil sociodemográfico nas atitudes face às PcD. Existe tendência para o recurso a metodologias quantitativas utilizando, como instrumento de recolha de dados, o questionário. O artigo termina identificando áreas de investigação relevantes para o aumento do conhecimento dos fatores que influenciam essas atitudes e, consequentemente, para o desenvolvimento do TA.


ABSTRACT: The investigation area of accessible tourism (AT) has a growing trend. However, most studies focus on physical accessibility, and only a few analyse the attitudes of students and professionals in this sector towards people with disabilities (PwD). This review aims to analyse the work carried out in other scientific areas on attitudes towards PwD. It is intended to map methodologies, measurement instruments and main variables and factors related with attitudes, to promote their inclusion in society. Research was carried out at Scopus and 492 records were obtained. Of these, 96 articles were selected for analysis. Results show that the assessment of attitudes towards PwD is a topic of great relevance in several scientific areas. Studies use several instruments to measure these attitudes. Previous experiences, quality, and frequency of contact with PwD and knowledge about disability have an influence on attitudes. However, results differ in the influence of the sociodemographic profile on attitudes towards PwD. There is a trend towards the use of quantitative methodologies, using the questionnaire as a tool for data collection. The article ends by identifying areas of research relevant to the increasing knowledge of the factors that influence these attitudes and, consequently, to the development of AT.

9.
Sci Total Environ ; 743: 140791, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32758844

RESUMO

This paper assesses the applicability of a new carob waste-derived powdered activated carbon (PAC) obtained by steam activation for pharmaceutical compounds (PhCs) removal in urban wastewater treatment plants (WWTPs) with activated sludge (AS) secondary treatment. The new carob-derived PAC presents chemical and textural properties similar to a high-performing commercial PAC produced from vegetable source by physical activation. The adsorption isotherms of three target PhCs, carbamazepine, diclofenac and sulfamethoxazole, spiked (at around 100 µg/L) in mixed liquor (ML) and in clarified-ML from the AS-bioreactor of a WWTP show: (i) minor reduction of PAC capacity with real MLs compared to clarified MLs; (ii) the higher the PhC hydrophobicity, the higher the PAC adsorption capacity in both water matrices; (iii) hydrophobic interactions probably overweight electrostatic interactions between the PhCs and the slightly positively charged PAC in these real water matrices with background organics and inorganics. The PhC adsorption results with ML and clarified-ML are used to calibrate the IAST-based tracer model (TRM) and predict the new PAC performance when added to AS-bioreactor vs. in post-secondary treatment, at the PhC naturally-occurring trace concentrations. The modelling projections show (i) one needs higher PAC doses than those reported in the literature, particularly in post-treatment, and (ii) the benefits of PAC dosing to the bioreactor, with only a slightly higher PAC dose being needed when compared to its post-secondary dosing and minimising the capital investment.


Assuntos
Poluentes Químicos da Água/análise , Purificação da Água , Adsorção , Carvão Vegetal , Galactanos , Mananas , Gomas Vegetais , Pós , Eliminação de Resíduos Líquidos , Águas Residuárias
10.
Water Sci Technol ; 81(2): 210-216, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32333654

RESUMO

Concentration polarization is a phenomenon inherent to membrane separation operations and as a precursor of membrane fouling is frequently related to the decrease in the performance of these operations. In the present work, a case-specific mass transfer correlation was developed to assess the concentration polarization when nanofiltration, in different operating conditions, was applied to treat a pharmaceutical wastewater containing atenolol. NF runs with two membranes, two atenolol concentrations and three feed circulating velocities were conducted, and the corresponding experimental mass transfer coefficients were determined using film theory to describe the concentration polarization phenomenon. Higher velocities led to higher mass transfer coefficients and, consequently, lower concentration polarization. These mass transfer coefficients were correlated with the circulating velocity (Re), the solute diffusivity (Sc) and the membrane permeability (LP +) (the membrane is a permeable interface with effect on the concentration profiles developed from the interface towards the bulk feed), yielding the following correlation Sh = 1.98 × 104Re0.5Sc0.33LP +0.32. The good agreement between the calculated and the experimental results makes this correlation a valuable tool for water practitioners to predict and control the concentration polarization during atenolol-rich wastewater treatment by nanofiltration, thereby increasing its productivity and selectivity.


Assuntos
Filtração , Purificação da Água , Atenolol , Membranas Artificiais , Águas Residuárias
11.
Wellcome Open Res ; 3: 19, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29774244

RESUMO

Background. Chronic pain is a common, often disabling condition thought to involve a combination of peripheral and central neurobiological factors. However, the extent and nature of changes in the brain is poorly understood. Methods. We investigated brain network architecture using resting-state fMRI data in chronic back pain patients in the UK and Japan (41 patients, 56 controls), as well as open data from USA. We applied machine learning and deep learning (conditional variational autoencoder architecture) methods to explore classification of patients/controls based on network connectivity. We then studied the network topology of the data, and developed a multislice modularity method to look for consensus evidence of modular reorganisation in chronic back pain. Results. Machine learning and deep learning allowed reliable classification of patients in a third, independent open data set with an accuracy of 63%, with 68% in cross validation of all data. We identified robust evidence of network hub disruption in chronic pain, most consistently with respect to clustering coefficient and betweenness centrality. We found a consensus pattern of modular reorganisation involving extensive, bilateral regions of sensorimotor cortex, and characterised primarily by negative reorganisation - a tendency for sensorimotor cortex nodes to be less inclined to form pairwise modular links with other brain nodes. Furthermore, these regions were found to display increased connectivity with the pregenual anterior cingulate cortex, a region known to be involved in endogenous pain control. In contrast, intraparietal sulcus displayed a propensity towards positive modular reorganisation, suggesting that it might have a role in forming modules associated with the chronic pain state. Conclusion. The results provide evidence of consistent and characteristic brain network changes in chronic pain, characterised primarily by extensive reorganisation of the network architecture of the sensorimotor cortex.

12.
Neuroimage Clin ; 20: 1026-1036, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30340201

RESUMO

Psychiatric illnesses are complex and polygenic. They are associated with widespread alterations in the brain, which are partly influenced by genetic factors. There have been some attempts to relate polygenic risk scores (PRS) - a measure of the overall genetic risk an individual carries for a disorder - to brain structure using univariate methods. However, PRS are likely associated with distributed and covarying effects across the brain. We therefore used multivariate machine learning in this proof-of-principle study to investigate associations between brain structure and PRS for four psychiatric disorders; attention deficit-hyperactivity disorder (ADHD), autism, bipolar disorder and schizophrenia. The sample included 213 individuals comprising patients with depression (69), bipolar disorder (33), and healthy controls (111). The five psychiatric PRSs were calculated based on summary data from the Psychiatric Genomics Consortium. T1-weighted magnetic resonance images were obtained and voxel-based morphometry was implemented in SPM12. Multivariate relevance vector regression was implemented in the Pattern Recognition for Neuroimaging Toolbox (PRoNTo). Across the whole sample, a multivariate pattern of grey matter significantly predicted the PRS for autism (r = 0.20, pFDR = 0.03; MSE = 4.20 × 10-5, pFDR = 0.02). For the schizophrenia PRS, the MSE was significant (MSE = 1.30 × 10-5, pFDR = 0.02) although the correlation was not (r = 0.15, pFDR = 0.06). These results lend support to the hypothesis that polygenic liability for autism and schizophrenia is associated with widespread changes in grey matter concentrations. These associations were seen in individuals not affected by these disorders, indicating that this is not driven by the expression of the disease, but by the genetic risk captured by the PRSs.


Assuntos
Transtorno Autístico , Transtorno Bipolar/patologia , Predisposição Genética para Doença , Herança Multifatorial/genética , Adulto , Idoso , Transtorno Autístico/genética , Transtorno Autístico/patologia , Transtorno Bipolar/genética , Encéfalo/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem , Fatores de Risco , Esquizofrenia/genética , Esquizofrenia/patologia
13.
Membranes (Basel) ; 8(3)2018 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-30037095

RESUMO

Concentration polarization is intrinsically associated with the selective character of membranes and often means flux decline and which causes a subsequent decrease of ultrafiltration and nanofiltration performance. More important is the fact that it acts as a precursor of membrane fouling and creates severe fouling problems in the longer times range. The quantification of its dependence on the operating parameters of cross-flow velocities and transmembrane pressures makes recourse to the film theory to introduce mass-transfer coefficients that generally are calculated by dimensionless correlations of the Sherwood number as a function of the Reynolds and Schmidt numbers. In the present work, the mass-transfer coefficients are obtained through the fitting of experimental results by the pressure variation method. The ultrafiltration/nanofiltration of the winery wastewaters from the racking operation is carried out with the membranes ETNA 01PP (Alfa Laval) and NF 270 (Dow Filmtec) under a wide range of cross-flow velocities and transmembrane pressures up to 15 bar.

14.
PLoS One ; 11(1): e0117603, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26731403

RESUMO

INTRODUCTION: High comorbidity among pediatric disorders characterized by behavioral and emotional dysregulation poses problems for diagnosis and treatment, and suggests that these disorders may be better conceptualized as dimensions of abnormal behaviors. Furthermore, identifying neuroimaging biomarkers related to dimensional measures of behavior may provide targets to guide individualized treatment. We aimed to use functional neuroimaging and pattern regression techniques to determine whether patterns of brain activity could accurately decode individual-level severity on a dimensional scale measuring behavioural and emotional dysregulation at two different time points. METHODS: A sample of fifty-seven youth (mean age: 14.5 years; 32 males) was selected from a multi-site study of youth with parent-reported behavioral and emotional dysregulation. Participants performed a block-design reward paradigm during functional Magnetic Resonance Imaging (fMRI). Pattern regression analyses consisted of Relevance Vector Regression (RVR) and two cross-validation strategies implemented in the Pattern Recognition for Neuroimaging toolbox (PRoNTo). Medication was treated as a binary confounding variable. Decoded and actual clinical scores were compared using Pearson's correlation coefficient (r) and mean squared error (MSE) to evaluate the models. Permutation test was applied to estimate significance levels. RESULTS: Relevance Vector Regression identified patterns of neural activity associated with symptoms of behavioral and emotional dysregulation at the initial study screen and close to the fMRI scanning session. The correlation and the mean squared error between actual and decoded symptoms were significant at the initial study screen and close to the fMRI scanning session. However, after controlling for potential medication effects, results remained significant only for decoding symptoms at the initial study screen. Neural regions with the highest contribution to the pattern regression model included cerebellum, sensory-motor and fronto-limbic areas. CONCLUSIONS: The combination of pattern regression models and neuroimaging can help to determine the severity of behavioral and emotional dysregulation in youth at different time points.


Assuntos
Comportamento do Adolescente , Sintomas Afetivos/diagnóstico , Mapeamento Encefálico , Imageamento por Ressonância Magnética , Transtornos Mentais/diagnóstico , Reconhecimento Automatizado de Padrão , Psicologia do Adolescente , Recompensa , Adolescente , Sintomas Afetivos/tratamento farmacológico , Sintomas Afetivos/patologia , Sintomas Afetivos/fisiopatologia , Escala de Avaliação Comportamental , Transtorno Bipolar/psicologia , Cerebelo/patologia , Cerebelo/fisiopatologia , Córtex Cerebral/patologia , Córtex Cerebral/fisiopatologia , Estudos de Coortes , Fatores de Confusão Epidemiológicos , Feminino , Seguimentos , Jogos Experimentais , Humanos , Sistema Límbico/patologia , Sistema Límbico/fisiopatologia , Masculino , Transtornos Mentais/tratamento farmacológico , Transtornos Mentais/patologia , Transtornos Mentais/fisiopatologia , Psicotrópicos/farmacologia , Psicotrópicos/uso terapêutico , Avaliação de Sintomas
15.
Water Sci Technol ; 72(4): 510-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26247748

RESUMO

The energy costs usually represent the second largest part of the running costs of a wastewater treatment plant (WWTP). It is therefore crucial to increase the energy efficiency of these infrastructures and to implement energy management systems, where quantitative performance metrics, such as performance indicators (PIs), play a key role. This paper presents energy PIs which cover the unit energy consumption, production, net use from external sources and costs, and the results used to validate them and derive their reference values. The results of a field study with 17 Portuguese WWTPs (5-year period) were consistent with the results obtained through an international literature survey on the two key parcels of the energy balance--consumption and production. The unit energy consumption showed an overall inverse relation with the volume treated, and the reference values reflect this relation for trickling filters and for activated sludge systems (conventional, with coagulation/filtration (C/F) and with nitrification and C/F). The reference values of electrical energy production were derived from the methane generation potential (converted to electrical energy) and literature data, whereas those of energy net use were obtained by the difference between the energy consumption and production.


Assuntos
Biocombustíveis/análise , Eletricidade , Metano/análise , Eliminação de Resíduos Líquidos/métodos , Eliminação de Resíduos Líquidos/normas , Águas Residuárias/análise , Filtração , Portugal , Esgotos/química
16.
J Environ Manage ; 146: 400-406, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25199602

RESUMO

The main goal of a wastewater treatment plant (WWTP) is to comply with the treated wastewater (TWW) quality requirements. However, the assessment of this compliance is a rather complex process for WWTPs in the EU Member States, since it requires the integration of a large volume of data and several criteria according to EU Directives 91/271/EEC and 2000/60/EC. A tool for a comprehensive assessment of TWW quality in this context is herein presented. The tool's novelty relies on an integrated analysis of performance indicators (PIs) and new performance indices (PXs). PIs integrate the several compliance criteria into a single framework, supported by flowcharts for a straightforward assessment of TWW compliance by practitioners. PXs are obtained by applying a performance function to the concentration values analysed in the TWW for discharge or reuse. PXs are dimensionless and the scale adopted (0-300) defines three performance levels: unsatisfactory, acceptable and good performance. The reference values proposed for these levels and for the PIs were based on the EU legislation. The PXs complement the information provided by the PIs. While the latter assess the plant effectiveness in a given year (i.e. the TWW compliance with the requirements), PXs tackle the plant reliability, i.e. they allow to easily compare the performance of different parameters over the time and to identify when the performance did satisfy or fail the pre-established objectives and the distance that remains to achieve these targets. The tool was tested in 17 WWTPs and the most representative results are herein illustrated.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Purificação da Água/normas , Humanos , Reprodutibilidade dos Testes , Purificação da Água/métodos
17.
Water Res ; 57: 202-14, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24721667

RESUMO

Removal efficiencies are often used to assess the performance of a single or a group of unit operations/processes (UOPs) of a wastewater treatment plant (WWTP). However, depending on the influent concentration (Cin), the same efficiency of removal (Er) may be insufficient or excessive to achieve the UOP or WWTP effluent quality requirements, expressed by concentration limit values (LVs). This paper proposes performance indices (PXs), Er-based, as new metrics for benchmarking, i.e. for assessing and improving the performance of each UOP or treatment step and ultimately of the WWTP as a multi-barrier system, and comprehensively describes the stepwise method of translating Ers into PXs. PXs are dimensionless and vary between 0 and 300 to define three performance levels: unsatisfactory (0-100), acceptable (100-200) and good (200-300) performance. The method developed takes into consideration Cin and LV, and the reference values for judging the performance are given from Er-Cin typical ranges and Er vs. Cin model curves, LV based and field data based. The general equations of the Er model curves are derived. A set of six curves is calibrated for TSS (Total Suspended Solids) and COD (Chemical Oxygen Demand) removal by primary sedimentation and activated sludge systems (carbon or combined carbon and nutrients removal), using 5-year (2006-2010) field data from five Portuguese WWTPs. A statistical analysis of the PX results is additionally proposed to assess treatment reliability. The new method is applied in two WWTPs and the PX results are compared with those of conventional measures - Er and performance indicators (PIs). The results demonstrate that, whereas a simplistic Er-driven or PI-driven management of the WWTPs shows limitations, the developed PXs are adequate measures for benchmarking removal efficiencies towards WWTP reliability and sustainability.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/análise , Purificação da Água/métodos , Análise da Demanda Biológica de Oxigênio , Carvão Vegetal/química , Portugal , Reprodutibilidade dos Testes , Esgotos/química
18.
PLoS One ; 9(3): e91090, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24609065

RESUMO

Neurofeedback based on real-time functional magnetic resonance imaging (fMRI) is a new approach that allows training of voluntary control over regionally specific brain activity. However, the neural basis of successful neurofeedback learning remains poorly understood. Here, we assessed changes in effective brain connectivity associated with neurofeedback training of visual cortex activity. Using dynamic causal modeling (DCM), we found that training participants to increase visual cortex activity was associated with increased effective connectivity between the visual cortex and the superior parietal lobe. Specifically, participants who learned to control activity in their visual cortex showed increased top-down control of the superior parietal lobe over the visual cortex, and at the same time reduced bottom-up processing. These results are consistent with efficient employment of top-down visual attention and imagery, which were the cognitive strategies used by participants to increase their visual cortex activity.


Assuntos
Rede Nervosa/fisiologia , Neurorretroalimentação , Córtex Visual/fisiologia , Adolescente , Adulto , Teorema de Bayes , Feminino , Humanos , Masculino , Modelos Neurológicos , Adulto Jovem
20.
Water Res ; 47(15): 5690-9, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23880216

RESUMO

A predictive model integrating adsorption kinetics and competitive isotherm models (Homogeneous Surface Diffusion Model, Freundlich-type and Fritz & Schlünder isotherms) was developed to describe and understand the competing mechanism(s) and the ionic strength (IS) role on microcystins (MC) and tannic acid (TA) competitive adsorption. The developed model showed good agreement with the experimental data obtained from batch adsorption tests and isotherms conducted with MC extracts and TA model solutions (single-solute and multicomponent, IS presence and absence) using a mesoporous powdered activated carbon (PAC). Results confirm that similar size molecules such as MC and TA are strong competitors and tannin-rich waters may severely affect MC residuals in the treated water. Unlike usually considered, both direct site and pore blockage mechanisms seem relevant. Competition effects appear to be more dependent on the competitor/contaminant molar ratio than on the initial concentrations. The IS affects the extent and the mechanisms of MC-TA competitive adsorption, reducing PAC dose for safe control of MC residuals. The developed model, including a Ds analysis, is an important tool to understand the competitive adsorption of similar size adsorbates.


Assuntos
Carvão Vegetal/química , Microcistinas/química , Taninos/química , Purificação da Água/métodos , Adsorção , Modelos Teóricos
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