bluuebunny/crossref_metadata_2025 huggingface dataset:
Water quality assessment of the Sinos River, Southern Brazil
Authors: Blume KK. , Macedo JC. , Meneguzzi A. , Silva LB. , Quevedo DM. , Rodrigues MAS
Published: January 2011

The Sinos River basin is located Northeast of the state of Rio Grande do Sul (29º 20' to 30º 10' S and 50º 15' to 51º20'W), Southern Brazil, covering two geomorphologic provinces: the Southern plateau and central depression. It is part of the Guaíba basin and has an area of approximately 800 km², encompassing 32 municipalities. The objective of this study was to monitor water quality in the Sinos River, the largest river in this basin. Water samples were collected at four selected sites in the Sinos River, and the following parameters were analysed: pH, dissolved oxygen, biochemical oxygen demand (BOD5), turbidity, fecal coliforms, total dissolved solids, temperature, nitrate, nitrite, phosphorous, chromium, lead, aluminum, zinc, iron, and copper. The results were analysed based on Resolution No. 357/2005 of the Brazilian National Environmental Council (CONAMA) regarding regulatory limits for residues in water. A second analysis was performed based on a water quality index (WQI) used by the Sinos River Basin Management Committee (COMITESINOS). Poor water quality in the Sinos River presents a worrying scenario for the region, since this river is the main source of water supply for the urban core. Health conditions found in the Sinos River, mainly in its lower reaches, are worrying and a strong indicator of human activities on the basin.
Rumo à pós-modernidade em políticas públicas: a epistemologia situacional de Carlos Matus
Authors: Fortis Martin Francisco de Almeida
Published: January 2011

O artigo discute a abordagem situacional desenvolvida por Carlos Matus, cujas técnicas operacionais (metodologia PES) foram bastante difundidas no âmbito do planejamento governamental, em contraste com a sua epistemologia, que permanece largamente ignorada no meio acadêmico especializado. Contestando a visão positivista e o economicismo reducionista da ortodoxia dominante, a epistemologia situacional propõe que as políticas públicas sejam pensadas dentro da lógica do jogo social, cujos fundamentos teóricos são complexidade, indeterminação e incerteza. Após descrição da trajetória intelectual de Carlos Matus, emprega-se a metodologia de pesquisa da análise bibliográfica com o propósito de investigar seus principais textos e evidenciar sua contribuição para uma orientação pós-moderna da gestão governamental. Revisando a literatura de políticas públicas, argumenta-se que a adoção da perspectiva situacional pode inspirar soluções alternativas aos problemas contemporâneos da administração pública, como a ampliação da eficiência administrativa e o fortalecimento democrático.
Colaboração interinstitucional em pesquisa no Brasil: tendências em artigos na área de gestão da inovação
Authors: Gazda Emmanuel , Quandt Carlos Olavo
Published: January 2011

O trabalho colaborativo em rede se expandiu a partir do final do século XX, apoiado pelos avanços nas tecnologias de informação e comunicação. A velocidade crescente das mudanças tecnológicas e o acirramento da competitividade internacional demandam esforços cooperativos de pesquisa e desenvolvimento entre organizações. Padrões similares de colaboração em rede são observados no meio acadêmico e suas relações com o setor produtivo. Este artigo visa contribuir para a identificação dos padrões de colaboração dos pesquisadores brasileiros. Para tanto, analisa-se a colaboração em produção científica na área de gestão da inovação por meio de um levantamento de coautoria dos artigos apresentados no Simpósio de Gestão da Inovação Tecnológica (Sigitec) no período 1998-2008. Verifica-se a ausência de uma tendência clara de crescimento da colaboração interinstitucional, que ainda é inferior aos níveis internacionais, bem como a persistência da concentração espacial da produção científica.
Relação dinâmica entre confiança, competitividade e o processo de tomada de decisão ética em negociação
Authors: Sobral Filipe João Bera de Azevedo
Published: January 2011

Os dilemas éticos são componentes inevitáveis da negociação, um processo de troca social central a todas as interações humanas. Por essa razão, é importante compreender o que motiva os gestores a agir de uma forma eticamente questionável em negociações empresariais. Usando uma amostra de 298 participantes em cursos de educação executiva, este estudo busca analisar em que medida diferenças individuais ao nível da personalidade condicionam o julgamento moral de práticas negociais eticamente ambíguas e as intenções comportamentais em seis cenários representativos de situações negociais que envolvem dilemas éticos. Os resultados sugerem que os dois traços de personalidade estudados - confiança interpessoal e competitividade - exercem uma influência significativa não apenas na forma como os gestores avaliam a moralidade de práticas negociais eticamente ambíguas, mas também na sua intenção comportamental em cenários negociais específicos. Os resultados podem contribuir para melhorar a compreensão do processo de tomada de decisão ética em negociação.
Temperatura do ar exalado, um novo biomarcador no controle da asma: um estudo piloto
Authors: Melo Raul Emrich , Popov Todor A , Solé Dirceu
Published: January 2011

OBJETIVO: Avaliar se a temperatura do ar exalado (TAE), medida por um método não invasivo, é efetiva no monitoramento de pacientes com asma não controlada. MÉTODOS: Estudo piloto com nove pacientes (sete mulheres e dois homens; média de idade: 39 anos) com diagnóstico de asma por pelo menos um ano e sem uso de tratamento de manutenção por pelo menos três meses antes do início do estudo. Na primeira visita, os pacientes foram submetidos à espirometria e à medida da TAE. Todos os pacientes foram orientados a iniciar tratamento com budesonida/formoterol (200/6 µg) inalatório a cada 12 h por seis semanas. Além disso, os pacientes com asma grave (VEF1 < 60% do previsto) foram orientados a utilizar prednisolona oral (40 mg/dia) por cinco dias. Após seis semanas, os pacientes foram submetidos aos mesmos testes. RESULTADOS: Todos os pacientes relataram melhora dos sintomas de asma; confirmada por um aumento significativo de VEF1 da primeira para a segunda visita (média de VEF1: 56,1% vs. 88,7% do previsto; p < 0,05). Cinco pacientes utilizaram prednisolona oral, mas somente nos cinco dias iniciais do tratamento. Seis pacientes utilizaram doses extras da medicação inalatória (média de tempo de uso de medicação adicional = 2,5 semanas). Houve uma diminuição significativa da TAE entre os momentos de avaliação (média de TAE: 35,1ºC vs. 34,1ºC; p < 0,05). CONCLUSÕES: A asma não controlada, sobretudo durante exacerbações, é acompanhada pela elevação da TAE, que se reduz após o controle adequado da asma, demonstrado pela melhora do VEF1 e dos sintomas referidos. Esses resultados preliminares apontam para o monitoramento da TAE como um parâmetro possível na avaliação do controle da asma.
Mobilidade diafragmática durante espirometria de incentivo orientada a fluxo e a volume em indivíduos sadios
Authors: Yamaguti Wellington Pereira dos Santos , Sakamoto Eliana Takahama , Panazzolo Danilo , Peixoto Corina da Cunha , Cerri Giovanni Guido , Albuquerque André Luis Pereira
Published: January 2011

OBJETIVO: Comparar a mobilidade diafragmática de indivíduos sadios durante a espirometria de incentivo orientada a volume, durante a espirometria de incentivo orientada a fluxo e durante exercícios diafragmáticos. Comparar a mobilidade diafragmática entre homens e mulheres durante esses três tipos de exercícios respiratórios. MÉTODOS: Foram avaliadas a função pulmonar e a mobilidade diafragmática de 17 voluntários sadios adultos (9 mulheres e 8 homens). A avaliação da mobilidade do diafragma foi realizada durante a execução de exercícios diafragmáticos e durante o uso dos dois tipos de espirômetros de incentivo, por meio de um método ultrassonográfico. RESULTADOS: A mobilidade diafragmática avaliada durante a utilização do espirômetro orientado a volume foi significativamente maior que aquela durante o uso do espirômetro orientado a fluxo (70,16 ± 12,83 mm vs. 63,66 ± 10,82 mm; p = 0,02). Os exercícios diafragmáticos promoveram maior mobilidade diafragmática do que o uso do espirômetro orientado a fluxo (69,62 ± 11,83 mm vs. 63,66 ± 10,82 mm; p = 0,02). Durante os três tipos de exercícios respiratórios, a relação mobilidade/CVF foi significativamente maior nas mulheres do que nos homens. CONCLUSÕES: A espirometria de incentivo orientada a volume e o exercício diafragmático promoveram maior mobilidade diafragmática do que a espirometria de incentivo orientada a fluxo. As mulheres apresentaram um melhor desempenho nos três tipos de exercícios respiratórios avaliados do que os homens.
Diagnóstico e tratamento da hipertensão pulmonar: uma atualização
Authors: Hoette Susana , Jardim Carlos , Souza Rogério de
Published: January 2011

Ao longo dos últimos cinco anos, o conhecimento na área de hipertensão pulmonar evoluiu de forma consistente e significativa. Novos algoritmos diagnósticos e de tratamento foram desenvolvidos com base no resultado de diversos estudos clínicos que evidenciaram a utilidade de novas ferramentas, assim como a eficácia de novos medicamentos e de combinações. Da mesma forma, a classificação da hipertensão pulmonar evoluiu, na tentativa de agrupar as diferentes formas de hipertensão pulmonar que apresentam abordagens diagnósticas e terapêuticas semelhantes a fim de facilitar a condução clínica dos pacientes. Esta revisão visa discutir cada uma dessas modificações, tendo por base as diretrizes brasileiras para manejo da hipertensão pulmonar de 2005, ressaltando aquilo que foi acrescentado às diretrizes internacionais.
Artrodese Cervical C1-C2 pelas técnicas de Harms e Magerl
Authors: Sousa Cristina Maria Varino , Silva Luís Pires , Santos Cláudia , Silva Eurico , Figueiredo José
Published: January 2011

INTRODUÇÃO: A instabilidade atlantoaxial pode resultar em alterações neurológicas, dor e limitação da mobilidade cervical. É uma situação grave pelo risco de tetraparésia ou morte súbita. Na literatura estão descritas várias técnicas de estabilização cirúrgica C1-C2 e neste artigo foram comentadas com maior ênfase as técnicas de Harms e Magerl, as mais utilizadas em nossa instituição. OBJETIVO: Descrever a casuística das artrodeses atlantoaxiais realizadas nos últimos cinco anos no Centro Hospitalar do Porto, particularmente, taxa de consolidações, complicações observadas, reintervenções e comparação com os estudos publicados. MÉTODOS: Estudo retrospectivo, com cinco anos, dos doentes submetidos a artrodese atlantoaxial no Centro Hospitalar do Porto. RESULTADOS: Foram operados 11 doentes no período do estudo, a maioria com instabilidade de causa traumática. O método de artrodese mais utilizado foi o descrito por Magerl. Não foram observadas lesões vasculares. Foram registradas complicações infecciosas em quatro doentes, sendo que essas infecções foram mais comuns em doentes com patologias inflamatórias de base. Obteve-se uma taxa de consolidação da artrodese de 100%; não foram necessárias cirurgias de revisão. CONCLUSÃO: Em nossa série, as artrodeses posteriores pelas técnicas de Harms e de Magerl resultaram em um ótimo controle da instabilidade C1-C2. Doentes com indicação de artrodese por instabilidade reumática apresentaram alta taxa de complicações infecciosas.
Avaliação tomográfica de parâmetros morfométricos do processo odontoide relacionados à fixação interna com parafusos
Authors: Daher Murilo Tavares , Daher Sérgio , Defino Helton LA
Published: January 2011

OBJETIVOS: avaliar, por meio da tomografia computadorizada, os parâmetros morfométricos do processo odontoide relacionados com a sua fixação interna. MÉTODOS: cinquenta e cinco exames de tomografia computadorizada (TC) da coluna cervical que permitissem o estudo do áxis foram utilizados para o estudo. Destes, 24 (47%) pertenciam a pacientes do sexo masculino e 31 do sexo feminino. A média de idade foi de 42,05 anos (± 15,82). Foram excluídos os casos com diagnóstico de tumores, infecções, sequelas de fratura, artrose muito avançada ou malformações congênitas. Nenhum dos exames tinha como indicação problemas relacionados à coluna cervical alta. Foram avaliados os seguintes parâmetros: 1 - comprimento estimado do implante (CEI), 2 - angulação do parafuso (aP), 3 - diâmetro transverso mínimo (DTmín) e 4 - diâmetro anteroposterior mínimo (DAPmín). Foi utilizado o teste t de Student para comparar os resultados entre o grupo de pacientes do sexo masculino e do feminino. RESULTADOS: o valor médio do CEI foi de 37,95 mm ± 3,44 para a população geral do estudo. O valor médio da angulação do parafuso (aP) foi de 60,91º ± 4,06. O diâmetro transverso mínimo (DTmín) foi de 9,05 mm ± 0,88 e o diâmetro antero-posterior mínimo DAPmín foi de 10,35 mm ±1,04. Os valores do CEI e do DAPmín na população masculina foram significativamente maiores do que aqueles encontrados na feminina, enquanto os outros parâmetros não apresentaram diferenças entre os dois sexos na população estudada. Dos 55 pacientes, 39% apresentaram DTmín < 9 mm, valor mínimo considerado para a colocação de dois parafusos de 3,5 mm. CONCLUSÕES: em nossa população, o sexo masculino apresentou valores significativamente maiores de CEI e DAPmín do que os encontrados no sexo feminino.
Metastatic adrenal pheochromocytoma to the thoracic spine
Authors: Scalfani Michael T. , Arnold Paul M. , Anderson Karen K.
Published: January 2011

To report on a case of pheochromocytoma metastases to the spine occurring more than 20 years after initial diagnosis. A 34-year-old female with a history of metastatic pheochromocytoma diagnosed at age 12 presented with weakness, heart palpitations, and circumferential back pain of five months duration. The patient had undergone multiple laparatomies for abdominal and hepatic metastases. Work-up revealed a destructive lesion at T9. After two weeks of preoperative phenoxybenzamine to control her hypertension, she underwent decompression, posterior fixation and fusion. Surgical intervention was followed by radiation therapy, zoledronic acid, and only one cycle of chemotherapy due to intolerance of side effects. The patient survived 25 years after original diagnosis, which far exceeds the average survival of less than 15 years. The patient died 26 months postoperatively due to progression of disease. Pheochromocytoma with spine metastases occurring more than 20 years after diagnosis is very uncommon, and should be considered in the differential diagnosis of a patient with a history of pheochromocytoma.
Drought forecasting using an aggregated drought index and artificial neural network
Authors: Barua S. , Perera B. J. C. , Ng A. W. M. , Tran D.
Published: January 2011

Early forecasting of future drought conditions during continuing dry periods can improve water resources management strategies. In this study, a drought forecasting approach is developed and presented using an aggregated drought index (ADI) and artificial neural network (ANN) using a monthly time step. The use of ADI forecasts the overall availability of water resources beyond the traditional forecasting of rainfall deficiency to represent future drought conditions. The paper compares two types of ANN; namely, recursive multi-step neural networks (RMSNN) and direct multi-step neural networks (DMSNN). The results show that the RMSNN approach is slightly better than the DMSNN approach for forecasts with lead time up to 3 months. The DMSNN approach gives slightly better results than the RMSNN approach when forecast lead time is over 3 months, and can give reasonable results up to 6 months ahead of forecasts.
A review of the adaptation and mitigation of global climate change using sustainable drainage in cities
Authors: Charlesworth S. M.
Published: January 2011

Sustainable drainage (SUDS) is well known for its equal emphasis on water quality, water quantity, amenity and biodiversity. What is now beginning to be realised is that this approach can also help mitigate the impacts of global climate change (GCC) and provide assistance to city dwellers in adapting to the changes which have already occurred. By using case studies from around the world, this paper illustrates how vegetated SUDS devices can sequester and store carbon, cool urban areas and increase perceptions of health and well-being in the populace. Both vegetated and hard-engineered structures can evaporate water contained within them and are thus being used in cities to cool the overlying air. Also shown is the extent to which SUDS devices such as green roofs and wet pavements are being used to mitigate the urban heat island effect, which, while not caused by climate change, exacerbates its impacts. Of the houses needed by 2040 in the UK, 80% already exist. In order to take advantage of the ability of SUDS to tackle some of the impacts of GCC, the emphasis must be placed on retrofitting technologies to existing buildings and this review proposes a simple hierarchy of suitable measures based on the density and land-use of the built-up area.
Recovery of reusable water from sewage using aerated flat-sheet membranes
Authors: Diamantis V. I. , Antoniou I. , Athanasoulia E. , Melidis P. , Aivasidis A.
Published: January 2011

Continuous developments and advances in membrane technology allow recovering to large extent reusable water from untraditional water sources, such as municipal effluents. In this paper, operational results and preliminary cost-analysis of a microfiltration (MF) process used for raw sewage and secondary effluent polishing are given. The research was conducted with a 22 sandwich-type flat-sheet membrane module (0.45 μm and 4.5 m2) employing aeration for fouling control. During raw sewage filtration the majority of the organics were retained (effluent COD < 90 mg/L and SS ∼ 0 mg/L). However, the fluxes were significantly lower [∼7 L/(m2 h)] compared to those achieved during secondary effluent filtration [∼29 L/(m2 h)] (at TMP 0.14 bar). In the second case, aeration was found to be suitable mean for fouling control. The total costs (capital and operational) for water recovery from raw sewage and secondary effluent were estimated to be in the order of 2 and 0.75 €/m3 respectively.
A neural network approach for on-line fault detection of nitrogen sensors in alternated active sludge treatment plants
Authors: Caccavale F. , Digiulio P. , Iamarino M. , Masi S. , Pierri F.
Published: January 2011

In this paper, an effective strategy for fault detection of nitrogen sensors in alternated active sludge treatment plants is proposed and tested on a simulated set-up. It is based on two predictive neural networks, which are trained using a historical set of data collected during fault-free operation of a wastewater treatment plant and their ability to predict reduced (ammonium) and oxidized (nitrates and nitrites) nitrogen is tested. The neural networks are also characterized by good generalization ability and robustness with respect to the influent variability with time and weather conditions. Then, simulations have been carried out imposing different kinds of fault on both sensors, as isolated spikes, abrupt bias and increased noise. Processing of residuals, based on the difference between measured concentration values and neural networks predictions, allows a quick revealing of the fault as well as the isolation of the corrupted sensor.
Cellular biopolymers and molecular structure of a secondary pulp and paper mill sludge verified by spectroscopy and chemical extraction techniques
Authors: Edalatmanesh Maryam , Sain Mohini , Liss Steven N.
Published: January 2011

For proper treatment, recycling, or disposal of the pulp and paper mill secondary sludge qualitative and quantitative determination of its characteristics are necessary. Chemical extraction, quantitative characterization, and spectroscopic experiments have been performed to determine the molecular composition and chemical functionality of a pulp and paper mill secondary sludge. In order to extract the low-molecular-weight substances, soxhlet extraction with polar and non-polar solvents was performed where most of the target substances (17 ± 1.3%.) were extracted after 2 hours. Over time, this extraction followed a first-order kinetics. Fiber analyses have shown 12 ± 3% lignin, 28 ± 3% cellulose, and 12 ± 4% hemicelluloses content. The ash content was about 17 ± 0.5%. In this work, 7 and 16% intra- and extracellular polymeric substances, respectively, were extracted from the secondary sludge. EPS and mixture of intra- and extracellular biopolymers have shown similar chemical functionalities. These analyses confirmed that the paper secondary sludge consisted mainly of wood fiber, i.e. lignocellulosic substances, along with proteins and polysaccharides originated from microorganisms.
Modeling the performance of biodegradation of textile wastewater using polyurethane foam sponge cube as a supporting medium
Authors: Lin Yen-Hui
Published: January 2011

A pilot-scale fixed-biofilm reactor (FBR) was established to treat textile wastewater to evaluate the feasibility of replacing conventional treatment processes that involve activated sludge and coagulation units. A kinetic model was developed to describe the biodegradation of textile wastewater by FBR. Batch kinetic tests were performed to evaluate the biokinetic parameters that are used in the model. FBR column test was fed with a mean COD of 692 mg/L of textile wastewater from flow equalization unit. The influent flow rate was maintained at 48.4 L/h for FBR column test. Experimental data and model-predicted data for substrate effluent concentration (as COD), concentration of suspended biomass in effluent and the amount of carbon dioxide (CO2) produced in the effluent agree closely with each other. Microscopic observations demonstrated that the biofilm exhibited a uniform distribution on the surface of polyurethane foam sponge. Under a steady-state condition, the effluent COD from FBR was about 14.7 mg COD/L (0.0213 Sb0), meeting the discharge standard (COD < 100 mg/L) that has been set by the government of Taiwan for textile wastewater effluent. The amount of biofilm and suspended biomass reached a maximal value in the steady state when the substrate flux reached a constant value and remained maximal. Approximately 33% of the substrate concentration (as COD) was converted to CO2 during biodegradation in the FBR test. The experimental and modeling schemes proposed in this study could be employed to design a full-scale FBR to treat textile wastewater.
Acetoclastic methanogens in an anaerobic digester could be susceptible to trace metal supplementation
Authors: Park C. , Bega A. , Unlu C. , Chadderton R. A. , McKean W. R. , Kohl P. M. , Hunt J. A. , Keaney J. , Willis J. L. , Duran M.
Published: January 2011

The objective of this study was to investigate the effects of nutrient supplementation on anaerobic biomass. While many studies emphasized the importance of supplementing trace metals such as iron, cobalt, and nickel for maximum methanogenic activity, there is no evidence whether such supplements, even at relatively low concentration, could perturb anaerobic biomass. Effects of supplementing nutrients, including yeast extract, on anaerobic biomass from two full-scale mesophilic digesters, operating under different conditions, at the North East Water Pollution Control Plant in Philadelphia, Pennsylvania, USA, were assessed using biochemical methane potential tests. The results show that acetoclastic methanogens from a recently cleaned digester was not stimulated by nutrient supplementation at relatively low concentrations and a slight perturbation was observed when supplementation was at a relatively high concentration. Furthermore, greater degree of susceptibility to the trace metal supplementation was observed for biomass from another digester that had not been cleaned for over 10 years, thus it had reduced active volume due to grit accumulation. For instance, supplementation of 200 mg/L of iron as FeCl2·4H2O to the biomass from the reduced-active-volume digester caused 17% reduction in CH4 production, as compared to a control which did not receive any supplements, while the same concentration had no effect on the biomass from full-active-volume digester. Results strongly suggest that acetoclastic methanogens stressed due to reduced hydraulic/solids retention time may be susceptible to trace metal addition. Therefore, trace metal supplementation for anaerobic digesters should be considered on a case by case basis.
Photo-assisted electrochemical degradation of the commercial herbicide atrazine
Authors: Malpass G. R. P. , Miwa D. W. , Gomes L. , Azevedo E. B. , Vilela W. F. D. , Fukunaga M. T. , Guimarães J. R. , Bertazzoli R. , Machado S. A. S. , Motheo A. J.
Published: January 2011

This paper presents a degradation study of the pesticide atrazine using photo-assisted electrochemical methods at a dimensionally stable anode (DSA®) of nominal composition Ti/Ru0.3Ti0.7O2 in a prototype reactor. The effects of current density, electrolyte flow-rate, as well as the use of different atrazine concentrations are reported. The results indicate that the energy consumption is substantially reduced for the combined photochemical and electrochemical processes when compared to the isolated systems. It is observed that complete atrazine removal is achieved at low current densities when using the combined method, thus reducing the energy required to operate the electrochemical system. The results also include the investigation of the phytotoxicity of the treated solutions.
Assessment of aquatic habitat effect by artificial change of streambed topography
Authors: Oh Kukryul , Lee Jooheon , Rubio Christabel J. , Kim Leehyung , Jeong Sangman
Published: January 2011

As interest in ecosystems and the environment has recently increased, efforts for the preservation and restoration of river ecosystems have increased. The purpose of this study is to estimate the fish physical habitat by artificial change of streambed topography applying two-dimensional simulation model, River2D. A total reach length of 130 m along the Je stream located within the Geum River basin in Korea was used in this study. The target fish is the dominant fish species, Zacco platypus, which was evaluated for two growth steps (adult and spawning). Five scenarios were considered which included the installation of small dams at three different heights (0.25 m, 0.50 m, and 1.00 m) and installation of small pool with 0.25 m and 0.50 m depth. Results indicated that for natural streambed conditions the adult optimum flow was 1 m3/s, and the spawning optimum flow was 3 m3/s. The mean annual outflow for the natural condition was 0.64 m3/s, lower than the evaluated optimum flows. Applying the three discharges observed in 2008 to the five scenarios, the installation of the small dam increased the weighted usable area (WUA) while the installation of pools decreased the WUA, both as compared to the WUA for the natural condition.
Modelling sewer sediment deposition, erosion, and transport processes to predict acute influent and reduce combined sewer overflows and CO2 emissions
Authors: Mouri Goro , Oki Taikan
Published: January 2011

Understanding of solids deposition, erosion, and transport processes in sewer systems has improved considerably in the past decade. This has provided guidance for controlling sewer solids and associated acute pollutants to protect the environment and improve the operation of wastewater systems. Although measures to decrease combined sewer overflow (CSO) events have reduced the amount of discharged pollution, overflows continue to occur during rainy weather in combined sewer systems. The solution lies in the amount of water allotted to various processes in an effluent treatment system, in impact evaluation of water quality and prediction technology, and in stressing the importance of developing a control technology. Extremely contaminated inflow has been a serious research subject, especially in connection with the influence of rainy weather on nitrogen and organic matter removal efficiency in wastewater treatment plants (WWTP). An intensive investigation of an extremely polluted inflow load to WWTP during rainy weather was conducted in the city of Matsuyama, the region used for the present research on total suspended solid (TSS) concentration. Since the inflow during rainy weather can be as much as 400 times that in dry weather, almost all sewers are unsettled and overflowing when a rain event is more than moderate. Another concern is the energy consumed by wastewater treatment; this problem has become important from the viewpoint of reducing CO2 emissions and overall costs. Therefore, while establishing a prediction technology for the inflow water quality characteristics of a sewage disposal plant is an important priority, the development of a management/control method for an effluent treatment system that minimises energy consumption and CO2 emissions due to water disposal is also a pressing research topic with regards to the quality of treated water. The procedure to improve water quality must make use of not only water quality and biotic criteria, but also modelling systems to enable the user to link the effect of changes in urban sewage systems with specific quality, energy consumption, CO2 emission, and ecological improvements of the receiving water.
Removal effect of Cr (VI) by adsorbent made from sewage sludge
Authors: Deng L. Y. , Xu G. R. , Yan Z. C. , Liu Q. H. , Li G. B.
Published: January 2011

Adsorbent made from sewage sludge is used to remove the Cr (VI) in wastewater. In this paper, the adsorption capacity, adsorption mechanism and regeneration of the adsorbent are studied. A systematic research is carried out to investigate the influence of adsorption capacities in various conditions, such as contact time, pH and initial dosage of adsorbent. The results show that: the equilibrium time is 6 h; the optimal pH is 2.5. The adsorption capacity increases as the initial concentration increase and as the dosage of activated carbon decrease. The data of adsorption capacity are more fit in Langmuir isotherms. The adsorption follows a pseudo-second-order kinetic model perfectly. From this research, the adsorption rate controlling step is film diffusion when the Cr (VI) concentration is low; otherwise, the adsorption rate controlling step is the diffusion among particles. The results of regeneration of saturated adsorbent show that the saturated adsorbent can be perfectly regenerated using alkali treatment. The regeneration ratio of the saturated adsorbent can reach more than 90% with proper concentration of alkali.
Photoelectrochemical degradation of methyl orange by TiO2 nanopore arrays electrode and its comparison with TiO2 nanotube arrays electrode
Authors: Liu Yanbiao , Gan Xiaojie , Zhou Baoxue , Li Jinhua , Zhang Jialing , Chen Yimin , Bai Jing , Zheng Qing , Liu Bingchuan , Cai Weimin
Published: January 2011

Highly ordered TiO2 nanopore arrays (TNPs) electrode was applied as an electrode material for photoelectrochemical (PEC) degradation of methylic orange (MO). As a comparison, the self-organized TiO2 nanotube arrays (TNAs) electrode about 500 nm in length was fabricated by Ti anodization in 0.5 wt% HF-H2O solution. The COD removal rate and color removal rate for PEC degradation of MO using the TNPs electrode was found to be 9 and 7%, respectively, as high as that obtained for TNAs electrode when biased at 0.5 V. The results indicate that the fast electron separation and transport properties of TNPs electrode makes it possesses enhanced PEC performance for the degradation of MO. In addition, the color removal rate of MO by TNPs PEC process increased with increasing bias potential and electrolyte concentration, but decreased with the increasing pH value and initial concentration of the reaction solution.
Ability of Beijerinckia indica to degrade phenanthrene and reduce hydraulic conductivity
Authors: Lim Dong-Hee , Lee Jai-Young , Lastoskie Christian M.
Published: January 2011

This study evaluates the ability of Beijerinckia indica (B. indica) as a biomaterial for aerobic biofilm barriers. B. indica's ability to remove phenanthrene was measured using a two-phase partitioning bioreactor. Approximately 500 mg/L of phenanthrene was gradually removed over a two week period under aerobic conditions of the bioreactor. B. indica's ability to reduce hydraulic conductivity was evaluated using rigid wall soil columns inoculated with the bacteria. B. indica formed a large quantity of strongly adhesive biofilm among soil particles, reducing the hydraulic conductivity in the soil columns by 2 or 3 orders of magnitude. To assess recovery of the biofilm, the formed biofilm was purposely destroyed by introducing landfill leachate into the soil columns. The biofilm recovery test showed that the hydraulic conductivity increased after leachate introduction. However, re-permeation of nutrient solution restored the permeability to its original lower value, which suggests a full recovery of the damaged biofilm. This study suggests that B. indica may be used as a possible biomaterial for aerobic biofilm barriers for the removal of phenanthrene from groundwater, provided that sufficient substrate and electron acceptor are provided to the treatment system.
Enhanced treatment of endocrine disrupting chemicals by a granular bed electrochemical reactor
Authors: Sakakibara Y. , Kounoike T. , Kashimura H.
Published: January 2011

Continuous treatments of trace endocrine disrupting chemicals (EDCs) such as 17β-estradiol (E2), bisphenol-A, nonylephenol, 4-t-octyl phenol and pentachlorophenol were carried out using a granular bed electrolytic reactor. Experimental results showed that the EDCs were removed by the reactor over 150 days and removal efficiencies were nearly the same in the presence and absence of humic substance. Energy consumption for the treatment was around several Wh/m3. For longer operation or higher loading conditions, Fenton oxidation was effective to regenerate electrodes. Calculated results by a mathematical model developed assuming liquid film mass-transfer as a rate-limiting step were in good agreement with observed results. Based on the model, enhancement of reactor performance was discussed.
Examination of sludge accumulation rates and sludge characteristics for a decentralized community wastewater treatment systems with individual primary clarifier tanks located in Wardsville (Ontario, Canada)
Authors: Lossing Heather , Champagne Pascale , McLellan P. James
Published: January 2011

In conventional septic systems, settling and partial treatment via anaerobic digestion occurs in the septic tank. One of the byproducts of solids separation in the septic tank is a semi-liquid material known as septage, which must be periodically pumped out. Septage includes the liquid portion within the tank, as well as the sludge that settles at the bottom of the tank and the scum that floats to the surface of the liquid layer. A number of factors can influence septage characteristics, as well as the sludge and scum accumulation rates within the tank. This paper presents the results of a 2007 field sampling study conducted in Wardsville (Ontario, Canada). The field study examined 29 individual residential two-chamber septic tanks in a community serviced by a decentralized wastewater treatment system in operation for approximately 7 years without septage removal. The field investigation provided a comprehensive data set that allowed for statistical analysis of the data to assess the more critical factors influencing solids accumulation rates within each of the clarifier chambers. With this data, a number of predictive models were developed using water usage data for each residence as an explanatory variable.
Demonstrating ultra-filtration and reverse osmosis performance using size exclusion chromatography
Authors: Henderson R. K. , Stuetz R. M. , Khan S. J.
Published: January 2011

Advanced water treatment plants employing ultrafiltration (UF) and reverse osmosis (RO) membrane processes are frequently implemented for the production of high-quality recycled water. It is important that process performance is able to be quantified and assessed to ensure it is fit for purpose. This research utilizes size exclusion chromatography with organic carbon, organic nitrogen and UV254 detection to determine the change in both DOC concentration and character through a UF/3 stage-RO pilot plant. It was determined that 97% of the influent DOC was removed on average to produce a water of less than 0.5 mg L−1 as C. The UF process removed more than half of the biopolymer fraction, equating to 4.5% DOC removal, while the RO process generally removed all DOC except a small proportion of the low MW humics and acids and low MW neutral fraction. While not changing significantly in concentration, the Stage 3 RO permeate typically contained low concentrations of humic fraction, indicating a change in character and therefore a change in rejection mechanism. Overall, it was determined that while TOC monitoring is important in advanced water treatment systems, improved understanding of the character of the TOC present lends greater insight into the assessment of process performance.
Assessment of hydraulic fish habitat condition using integrated toolkit: a case study of the Geum river basin, Republic of Korea
Authors: Park Sangyoung , Kim Jeongkon , Ko Ick Hwan , Arthington Angela , Jones Gary , Yum Kyung Taek
Published: January 2011

Artificial changes of rivers, including construction and operation of dams, inevitably lead to physical and ecological changes throughout waterways and their floodplains. In this study, a conceptual model coupled with integrated numerical modeling is presented for hydraulic fish habitat assessment of the Geum River basin, Republic of Korea. Based on the major events which might have affected the ecological system, a conceptual model was formulated to guide desktop and field studies, modeling and scenario evaluations. The result of hydraulic fish habitat assessment indicated that the construction of the Daecheong Multipurpose Dam (DMD) in the Geum River basin has altered flow magnitudes and reduced the river's flow variability. Changes are evident in the magnitude of medium and small flows and the river experiences increased low flows during the dry season. Black shiner, an endangered fish species in Korea, was selected and analyzed to explore relationships between flow regime change by dams and changes to its preferred habitats. As a result, fewer sensitive riffle-benthic species were observed in the reaches downstream of DMD due to the reduction of suitable habitat conditions such as riffle-pool sequences. The proposed conceptual model and integrated toolkit would allow river managers to isolate the physical and biological effects associated with dam operation and could be useful for developing river management strategies.
Nonpoint-source nitrogen and phosphorus behavior and modeling in cold climate: a review
Authors: Han Cheng-Wei , Xu Shi-Guo , Liu Jian-Wei , Lian Jian-Jun
Published: January 2011

Pollution from nonpoint-source (NPS) nitrogen (N) and phosphorus (P) are the main causes of eutrophication in lotic, lentic and coastal systems. The climate of cold regions might play an important role in disturbing environmental behavior of NPS N and P, influencing simulation of watershed scale hydrologic and nonpoint-source pollution models. The losses of NPS N and P increase in regions of cold climate. In cold seasons, accumulations of N and P are accelerated in soil with increasing fine root and aboveground biomass mortality, decreasing plant nutrient uptake, as well as freezing soil. N and P transformation is disturbed by soil frost and snow. Moreover, factors such as physical disruption of soil aggregates, pollutant accumulation in snowpack, and snow melting can all increase the NPS N and P losses to the waterbody. Therefore, NPS N and P in first flush are more serious in cold climate. All these effects, especially frozen soil and snowpack, make great challenges to watershed scale hydrologic and nonpoint-source pollution models simulation in cold climate. Model improvements of snowmelt runoff, nutrient losses in frozen soil, as well as N and P behavior have been initiated and will be continued to evaluate in terms of their performances and suitability with different scale, hydrologic and geologic conditions in the future.
Fate of selected pharmaceuticals and personal care products after secondary wastewater treatment processes in Taiwan
Authors: Lin Angela Yu-Chen , Lin Cheng-Fan , Tsai Yu-Ting , Lin Hank Hui-Hsiang , Chen Jie , Wang Xiao-Huan , Yu Tsung-Hsien
Published: January 2011

Pharmaceuticals and personal care products (PPCPs) constitute a class of chemicals of emerging concern due to the potential risks they pose to organisms and the environment, even at low concentrations (ng/L). Recent studies have found that PPCPs are not efficiently removed in secondary wastewater treatment plants (WWTPs). This study has: (1) simultaneously investigated the occurrence of sixty-one PPCPs using solid phase extraction and high-performance liquid chromatography-tandem mass spectrometry, (2) evaluated removal efficiencies of target PPCPs in six WWTPs that discharge effluents into major Taiwanese rivers, and lastly (3) examined matrix interference during analysis of target PPCPs in water samples. The twenty target PPCPs were chosen for their high detection frequencies, high influent concentrations, and stability during wastewater treatment processes. Caffeine and acetaminophen were detected at the highest concentrations (as high as 24,467 and 33,400 ng/L) and were effectively removed (both >96%); other PPCPs were detected in the high ng/L range but were not effectively removed. Matrix interference (by ion suppression or enhancement) during the analysis resulted in underestimation of the removal efficiencies of erythromycin-H2O, cefazolin, clarithromycin, ibuprofen, diclofenac, clofibric acid and gemfibrozil.
CFD modelling of flow field and particle tracking in a hydrodynamic stormwater separator
Authors: Lee J. H. , Bang K. W. , Choi C. S. , Lim H. S.
Published: January 2011

The best management practices (BMPs) for control of urban stormwater pollution are evaluated to remove solid particles containing various pollutants. Currently, most storm runoff treatment devices using primary pollutant removal mechanism are applied to storm water since most pollutants in runoff are associated with the solid particulates. A hydrodynamic separator is a storm water treatment device using centrifugal motion which separates solids pollution from runoff. In this study, the velocity flow field and particle tracking of hydrodynamic separator were investigated using anthracite as a computational fluid dynamics (CFD) model particle. The Fluent 6.3.26 CFD program was used to predict the solid particles removal efficiency for various parameters such as particle size, surface loading rate, and the ratio of underflow to overflow. The velocity flow field in a hydrodynamic stormwater separator (HDS) has been simulated using CFD RNG κ-ɛ model. Modeling results for the removal efficiency of HDS were similar with the results obtained from experimental measurements of laboratory scale HDS. These results showed that the simulated velocity field was useful to interpret the behavior of flow in the hydrodynamic separator. The results obtained from particle tracking can be applied to predict the separation efficiency.
Urban pluvial flooding in Jakarta: applying state-of-the-art technology in a data scarce environment
Authors: Hurford A. P. , Maksimović Č. , Leitão J. P.
Published: January 2011

Available data relating to major pluvial flooding events in Jakarta, Indonesia were used to investigate the suitability of two different levels of sophistication in urban modelling tools for modelling these events. InfoWorks CS v9.0 was employed to build 1D and 1D/2D models of a 541 ha area of inner city Ciliwung River catchment which has a history of being particularly badly affected by flooding during heavy rainfall events. The study demonstrated that a 1D model was sufficient to simulate the flood extent of a major event using the limited data available. While the 1D/2D model also performed well, more data and time would have been required to match the 1D model's simulation of flood extent. Much more detailed data would have been required to produce reliable results in the 1D/2D model and to enable any kind of verification or calibration of the two models beyond visual comparison with crude flood extent maps.
Modeling and verification of selective sludge discharge as the controlling factor for aerobic granulation
Authors: Li A. J. , Zhang T. , Li X. Y.
Published: January 2011

Mathematical simulation and laboratory experiments were conducted to investigate the controlling factor for aerobic sludge granulation. A model was used to describe the biomass dynamics during the granulation process. The simulation results indicate that the selective discharge of small and loose sludge flocs is the key controlling factor for granulation. In the experimental studies, tests were conducted with four batch column reactors (BCR) that were seeded with both activated sludge flocs and mature granules. Three different sludge discharge methods were tested, including unselective discharge of mixed sludge, selective discharge of small and slow-settling flocs, and selective discharge of settled dense sludge. The results show that mixed sludge discharge and discharge of dense sludge resulted in disappearance of granules from the reactors. Only selective discharge of small and slow-settling sludge flocs led to complete granulation. Small and loose sludge flocs were found to have a clear advantage over large and dense granules in substrate uptake. It can be concluded that selective discharge of loose flocs removes these competitors in suspended-growth mode from the reactors and makes the substrate more available for uptake and utilization by the biomass in attached-growth form, leading to granulation.
Constructed wetland for water quality improvement: a case study from Taiwan
Authors: Wu C. Y. , Liu J. K. , Cheng S. H. , Surampalli D. E. , Chen C. W. , Kao C. M.
Published: January 2011

In Taiwan, more than 20% of the major rivers are mildly to heavily polluted by domestic, industrial, and agricultural wastewaters due to the low percentage of sewers connected to wastewater treatment plants. Thus, constructed or engineered wetlands have been adopted as the major alternatives to clean up polluted rivers. Constructed wetlands are also applied as the tertiary wastewater treatment systems for the wastewater polishment to meet water reuse standards with lower operational costs. The studied Kaoping River Rail Bridge Constructed Wetland (KRRBCW) is the largest constructed wetland in Taiwan. It is a multi-function wetland and is used for polluted creek water purification and secondary wastewater polishment before it is discharged into the Kaoping River. Although constructed wetlands are feasible for contaminated water treatment, wetland sediments are usually the sinks for organics and metals. In this study, water and sediment samples were collected from the major wetland basins in KRRBCW. The investigation results show that more than 97% of total coliforms (TC), 55% of biochemical oxygen demand (BOD), and 30% of nutrients [e.g. total nitrogen (TN), total phosphorus (TP)] were removed via the constructed wetland system. However, results from the sediment analyses show that wetland sediments contained high concentrations of metals (e.g. Cu, Fe, Zn, Cr, and Mn), organic contents (sediment oxygen demand = 1.7 to 7.6 g O2/m2 d), and nutrients (up to 18.7 g/kg of TN and 1.22 g/kg of TN). Thus, sediments should be excavated periodically to prevent the release the pollutants into the wetland system and causing the deterioration of wetland water quality. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal that a variation in microbial diversity in the wetland systems was observed. Results from the DGGE analysis indicate that all sediment samples contained significant amounts of microbial ribospecies, which might contribute to the carbon degradation and nitrogen removal. Gradual disappearance of E. coli was also observed along the flow courses through natural attenuation mechanisms.