Multiple Linear Regression and Artificial Neural Networks to Predict Time and Efficiency of Soil Vapor Extraction

The prediction of the time and the efficiency of the remediation of contaminated soils using soil vapor extraction remain a difficult challenge to the scientific community and consultants. This work reports the development of multiple linear regression and artificial neural network models to predict the remediation time and efficiency of soil vapor extractions performed in soils contaminated separately with benzene, toluene, ethylbenzene, xylene, trichloroethylene, and perchloroethylene. The results demonstrated that the artificial neural network approach presents better performances when compared with multiple linear regression models. The artificial neural network model allowed an accurate prediction of remediation time and efficiency based on only soil and pollutants characteristics, and consequently allowing a simple and quick previous evaluation of the process viability.

Synthesis of titanate nanofibers co-sensitized with ZnS and Bi2S3 nanocrystallites and their application on pollutants removal

The synthesis of nanocomposite materials combining titanate nanofibers (TNF) with nanocrystalline ZnS and Bi2S3 semiconductors is described in this work. The TNF were produced via hydrothermal synthesis and sensitized with the semiconductor nanoparticles, through a single-source precursor decomposition method. ZnS and Bi2S3 nanoparticles were successfully grown onto the TNF's surface and Bi2S3-ZnS/TNF nanocomposite materials with different layouts. The samples' photocatalytic performance was first evaluated through the production of the hydroxyl radical using terephthalic acid as probe molecule. All the tested samples show photocatalytic ability for the production of this oxidizing species. Afterwards, the samples were investigated for the removal of methylene blue. The nanocomposite materials with best adsorption ability were the ZnS/TNF and Bi2S3ZnS/TNF. The dye removal was systematically studied, and the most promising results were obtained considering a sequential combination of an adsorption-photocatalytic degradation process using the Bi2S3ZnS/TNF powder as a highly adsorbent and photocatalyst material. (C) 2015 Elsevier Ltd. All rights reserved.

What is the shape of an air bubble on a liquid surface?

We have calculated the equilibrium shape of the axially symmetric meniscus along which a spherical bubble contacts a flat liquid surface by analytically integrating the Young-Laplace equation in the presence of gravity, in the limit of large Bond numbers. This method has the advantage that it provides semianalytical expressions for key geometrical properties of the bubble in terms of the Bond number. Results are in good overall agreement with experimental data and are consistent with fully numerical (Surface Evolver) calculations. In particular, we are able to describe how the bubble shape changes from hemispherical, with a flat, shallow bottom, to lenticular, with a deeper, curved bottom, as the Bond number is decreased.

Avalia����o da Qualidade do Ar Interior de Gin��sios

A pr��tica de exerc��cio f��sico �� considerado condi����o essencial para a manuten����o de uma boa sa��de. A faixa et��ria de frequentadores de gin��sios inclui utentes desde os 8 aos 80 anos, incluindo assim os grupos mais sens��veis �� polui����o do ar interior. Embora exista legisla����o espec��fica para gin��sios, nomeadamente para as condi����es de implementa����o, a mesma �� reduzida e n��o contempla a qualidade do ar interior (QAI). O objetivo geral deste estudo consistiu na avalia����o da QAI de quatro gin��sios existentes na ��rea metropolitana do Porto. O per��odo de amostragem realizou-se entre 2 de Maio e 20 de Junho 2014 e, ap��s a caracteriza����o dos gin��sios, foram monitorizados os seguintes par��metros: part��culas ultrafinas (< 100 nm), mat��ria particulada suspensa no ar de fra����es PM1, PM2,5, PM4 e PM10, di��xido de carbono, mon��xido de carbono, ozono, compostos org��nicos vol��teis, formalde��do, temperatura ambiente e humidade relativa durante 24 h/dia em salas com diferentes actividades (sala de muscula����o e cardiofitness e sala de aulas de grupo). Os resultados da avalia����o dos par��metros f��sicos e qu��micos foram comparados com os limiares de prote����o e margem de toler��ncia do Decreto-Lei n�� 118/2013 de 20 de Agosto, a Portaria n�� 353-A/2013 de 4 de Dezembro e o Diploma que regula a constru����o, instala����o e funcionamento dos gin��sios. Os poluentes com maiores n��veis de exced��ncia s��o o di��xido de carbono, compostos org��nicos vol��teis e as part��culas PM2,5. As exced��ncias devem-se essencialmente �� sobrelota����o das salas, excesso de atividade f��sica e ventila����o insuficiente. A localiza����o da instala����o dos gin��sios �� tamb��m um fator de extrema import��ncia, sendo recomendado que este se situe em local pouco influenciado pelo tr��fego autom��vel, assim como, afastado de locais de poss��vel interfer��ncia devido ��s atividades presentes, como �� o caso da restaura����o existente em centros comerciais.

Consumption Management of Air Conditioning Devices for the Participation in Demand Response Programs

Demand Response has been taking over the years an extreme importance. There���s a lot of demand response programs, one of them proposed in this paper, using air conditioners that could increase the power quality and decrease the spent money in many ways like: infrastructures and customers energy bill reduction. This paper proposes a method and a study on how air conditioners could integrate demand response programs. The proposed method has been modelled as an energy resources management optimization problem. This paper presents two case studies, the first one with all costumers participating and second one with some of costumers. The results obtained for both case studies have been analyzed.

Polycyclic aromatic hydrocarbons: levels and phase distributions in preschool microenvironment

This work aims to characterize levels and phase distribution of polycyclic aromatic hydrocarbons (PAHs) in indoor air of preschool environment and to assess the impact of outdoor PAH emissions to indoor environment. Gaseous and particulate (PM1 and PM2.5) PAHs (16 USEPA priority pollutants, plus dibenzo[a,l]pyrene, and benzo[j]fluoranthene) were concurrently sampled indoors and outdoors in one urban preschool located in north of Portugal for 35 days. The total concentration of 18 PAHs (��PAHs) in indoor air ranged from 19.5 to 82.0 ng/m3; gaseous compounds (range of 14.1���66.1 ng/m3) accounted for 85% ��PAHs. Particulate PAHs (range 0.7���15.9 ng/m3) were predominantly associated with PM1 (76% particulate ��PAHs) with 5-ring PAHs being the most abundant. Mean indoor/outdoor ratios (I/O) of individual PAHs indicated that outdoor emissions significantly contributed to PAH indoors; emissions from motor vehicles and fuel burning were the major sources.

Trace Elements in Ambient Air at Porto Metropolitan Area���Checking for Compliance with New European Union (Eu) Air Quality Standards

Because of the scientific evidence showing that arsenic (As), cadmium (Cd), and nickel (Ni) are human genotoxic carcinogens, the European Union (EU) recently set target values for metal concentration in ambient air (As: 6 ng/m3, Cd: 5 ng/m3, Ni: 20 ng/m3). The aim of our study was to determine the concentration levels of these trace elements in Porto Metropolitan Area (PMA) in order to assess whether compliance was occurring with these new EU air quality standards. Fine (PM2.5) and inhalable (PM10) air particles were collected from October 2011 to July 2012 at two different (urban and suburban) locations in PMA. Samples were analyzed for trace elements content by inductively coupled plasma���mass spectrometry (ICP-MS). The study focused on determination of differences in trace elements concentration between the two sites, and between PM2.5 and PM10, in order to gather information regarding emission sources. Except for chromium (Cr), the concentration of all trace elements was higher at the urban site. However, results for As, Cd, Ni, and lead (Pb) were well below the EU limit/target values (As: 1.49 �� 0.71 ng/m3; Cd: 1.67 �� 0.92 ng/m3; Ni: 3.43 �� 3.23 ng/m3; Pb: 17.1 �� 10.1 ng/m3) in the worst-case scenario. Arsenic, Cd, Ni, Pb, antimony (Sb), selenium (Se), vanadium (V), and zinc (Zn) were predominantly associated to PM2.5, indicating that anthropogenic sources such as industry and road traffic are the main source of these elements. High enrichment factors (EF > 100) were obtained for As, Cd, Pb, Sb, Se, and Zn, further confirming their anthropogenic origin.

Projeto de uma ETAR para a freguesia de Canelas, Penafiel

O tratamento das ��guas residuais dom��sticas surge com o intuito de degradar os poluentes presentes, para que as ��guas residuais tratadas n��o prejudiquem o ambiente nem a sa��de p��blica. O presente trabalho teve como objetivo a conce����o e o dimensionamento de uma Esta����o de Tratamento de ��guas Residuais (ETAR) na freguesia de Canelas com a finalidade de substituir a j�� existente e permitir a amplia����o da ��rea da rede de saneamento da freguesia. Foram considerados dois tipos de ETAR���s, compacta e convencional, para tratar ��guas residuais dom��sticas de aproxidamente 2000 habitantes, com um caudal m��dio de 400 m3/dia e um caudal de ponta de 1136,7 m3/dia. Das duas op����es optou-se pela convencional uma vez que acarreta um menor investimento, no valor de 187 232 ���, e se considera tamb��m mais adequada ��s caracter��sticas do efluente a tratar. O tratamento escolhido inclui inicialmente uma gradagem, com uma grade constitu��da por sete barras com um espa��amento de 20 mm entre elas, seguida de um tamisador rotativo com uma abertura de malha de 3 mm. Depois do tamisador, optou-se por um sistema de desarena����o/desengorduramento com um volume do tanque de 3,95 m3 e um fluxo de ar de 17,9 m3/h. Na fase seguinte considerou-se um tratamento biol��gico por lamas ativadas em regime de arejamento prolongado num tanque de arejamento de volume igual a 245,8 m3 com um arejador submerso, seguindo-se um decantador secund��rio de volume 33,3 m3. Por ��ltimo, escolheu-se um sistema de desinfe����o por ultravioleta e, a montante do mesmo, um filtro r��pido para eliminar pequenas part��culas que o efluente ainda possa conter. Para a desinfe����o foram consideradas duas sec����es com cinco m��dulos de duas l��mpadas cada, ou seja, vinte l��mpadas ultravioleta. Dos res��duos produzidos pelo tratamento da ��gua residual, os gradados e as areias ser��o encaminhados para aterro, enquanto que as lamas ser��o enviadas para a ETAR das Termas de S.Vicente, para que sofram o tratamento adequado e sejam encaminhadas para o destinal final adequado (aplica����o em solos agr��colas, compostagem ou em alternativa para aterro). No caso da ETAR covencional foi ainda avaliada a poss��vel reutiliza����o de um decantador da ETAR de Milhundos uma vez que esta se encontrava em fase de desativa����o. Desta avalia����o, concluiu-se que n��o seria economicamente vi��vel o seu reaproveitamento. Mestrado em Engenharia Qu��mica ��� Tecnologias de Prote����o Ambiental Para al��m disso realizou-se tamb��m um levantamento dos principais problemas que ocorrem na maioria das ETAR���s e foram apresentadas as respetivas sugest��es de resolu����o. A realiza����o de um inqu��rito permititu concluir que os odores s��o o problema que mais causa inc��modo �� popula����o.

Modelling and optimization of the ion exchange membrane bioreactor for removal of anionic pollutants from drinking water streams

Disserta����o para obten����o do Grau de Doutor em Engenharia Qu��mica, especialidade de Engenharia Bioqu��mica

Gas emissions on rice culture and its importance on air quality

Disserta����o para obten����o do Grau de Mestre em Engenharia do Ambiente Perfil Gest��o de Sistemas Ambientais

Evaluation of air lime and clayish earth mortars for earthen wall renders

CIAV2013 ��� International Conference on Vernacular Architecture, 7�� ATP, VerSus, 16-20 october 2013

Identification of atmospheric pollutants control mechanisms during co-combustion of coal and non-toxic wastes

Doctoral dissertation for Ph.D. degree in Sustainable Chemistry

Electrodialytic remediation of two types of air pollution control residues and their applicability in construction materials

Disserta����o para obten����o do Grau de Mestre em Engenharia do Ambiente Perfil de Engenharia de Sistemas Ambientais

Air lime-earth blended mortars - Assessment on fresh state and workability

International Conference on Vernacular Heritage, Sustainability and Earthen Architecture, VerSus 2014, 2nd MEDITERRA, 2nd ResTAPIA, 11-13 September, Valencia, Spain