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Study of liposomes stability containing soy phosphatidyleholine and hydrogenated soy phosphatydylcholine adding or not cholesterol by turbidity method

Chorilli, Marlus; Rimerio, Thereana Cristina; de Oliveira, Anselmo Gomes; Scarpa, Maria Virginia
Fonte: Colegio de Farmaceuticos de La Provincia de Buenos Aires Publicador: Colegio de Farmaceuticos de La Provincia de Buenos Aires
Tipo: Artigo de Revista Científica Formato: 31-37
SPA
Relevância na Pesquisa
37.27%
Study of Liposomes Stability Containing Soy Phosphatidyleholine and Hydrogenated Soy Phosphatydylcholine Adding or Not Cholesterol by Turbidity Method. Liposomes are structures composed by phospholipids as soy phosphatidylcholine (PC) and hydrogenated soy phosphatydylcholine (PCH). Among the methods used to prove liposomes stability, turbidity method is widely used. The objective of this work was to study the liposomes stability containing PC or PCH with and without cholesterol (CHOL) by turbidity method. Liposomes were stored a 30 degrees C during 90 days and periodically absorbance readings at 410 nm were made to verify possible turbidity alterations. Increases in the turbidity with time occurred for PC liposomes. In the presence of CHOL higher turbidity was obtained probably reflecting the increase in the size of liposomes. For PCH liposomes the presence of CHOL did not affect the turbidity suggesting higher physical stability of the structures.

Aplicabilidade do método 1623 e do método de filtração em membranas para detecção de cistos de Giardia spp. e oocistos de Cryptosporidium spp. em amostras hídricas considerando diferentes faixas de turbidez, e estudo da etapa de purificação por separação imunomagnética = : Applicability of method 1623 and membrane filtration method for detection of Giardia spp. cysts and Cryptosporidium spp. oocysts in water samples considering different levels of turbidity, and study of immunomagnetic separation phase; Applicability of method 1623 and membrane filtration method for detection of Giardia spp. cysts and Cryptosporidium spp. oocysts in water samples considering different levels of turbidity, and study of immunomagnetic separation phase

Diego de Oliveira Pinto
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 19/08/2013 PT
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37.15%
Os protozoários patogênicos Giardia spp. e Cryptosporidium spp. estão entre os principais contaminantes associados à veiculação hídrica e seu monitoramento em águas de abastecimento público é determinado pela Portaria n. 2.914/2011, do Ministério da Saúde do Brasil. Este trabalho foi dividido em duas partes. Na primeira, foi realizado um estudo da aplicabilidade do Método 1623 utilizando Filta-Max® (FMx) e Método de Filtração em Membranas (FM). Cistos de Giardia spp. e oocistos de Cryptosporidium spp. foram inoculados artificialmente em amostras de água bruta superficial proveniente do rio Atibaia, coletadas na cidade de Campinas/SP, Brasil, e agrupadas de acordo com faixas de turbidez. Cistos de Giardia spp. naturalmente presentes nas amostras foram detectados em todas as faixas de turbidez por ambos os métodos. O método de FM atendeu aos critérios de controle de qualidade analítica da USEPA em todas as faixas de turbidez. Não houve diferença estatística significativa entre os métodos de FMx e FM. Na segunda parte deste trabalho, foi feito um estudo da etapa de purificação por Separação Imunomagnética (IMS) no qual foi avaliado o desempenho dos procedimentos de dissociação: ácida e térmica; bem como investigado possíveis causas de perdas dos organismos-alvo durante execução desta etapa. A dissociação ácida apresentou maior média de eficiência de recuperação e precisão do que a dissociação térmica para cistos de Giardia spp.. Para oocistos de Cryptosporidium spp. não houve diferença estatística significativa. Após o procedimento de dissociação...

Satellite remote sensing of water turbidity in Alqueva reservoir

Potes, Miguel; Costa, Maria João; Salgado, Rui
Fonte: Fifth Meeting of Post-Graduation in Physics and Earth Sciences of University of Évora (PGUE2011) Publicador: Fifth Meeting of Post-Graduation in Physics and Earth Sciences of University of Évora (PGUE2011)
Tipo: Aula
ENG
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36.98%
The quality control and monitoring of surface freshwaters is crucial, since some of these water masses constitute essential renewable water resources for a variety of purposes. The water turbidity is related with extinction of light in water and consequently with thermal vertical structure of the lakes, which in turn plays an important role in autochthonous primary production. Recently [3] developed a method to retrieve surface freshwater biological parameters (chlorophyll a and cyanobacteria) concentrations over Alqueva reservoir (south of Portugal) from MERIS satellite data, aiming at providing full spatial coverage and continuous monitoring of these parameters that affect the water quality. The methodology is now adapted and presented here to obtain a new empirical algorithm allowing retrieving the water turbidity of the same reservoir, which is important for the estimation of water extinction coefficients.

Satellite remote sensing of water turbidity in Alqueva reservoir and implications on lake modelling

Potes, Miguel; Costa, Maria João; Salgado, Rui
Fonte: European Geosciences Union - EGU Publicador: European Geosciences Union - EGU
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.15%
The quality control and monitoring of surface freshwaters is crucial, since some of these water masses constitute essential renewable water resources for a variety of purposes. In addition, changes in the surface water composition may affect physical properties of the lake water, such as temperature, which in turn may impact exchanges with the lower troposphere. The use of satellite remote sensing to estimate water turbidity of Alqueva reservoir, located in the south of Portugal, is explored. A validation study of the satellite derived water leaving spectral reflectance is firstly presented, using data taken during three field campaigns carried out during 2010 and early 2011. Secondly an empirical algorithm to estimate lake water surface turbidity from the combination of in situ and satellite measurements is proposed. The importance of water turbidity on the surface energy balance is tested in the form of a lake model sensitivity study to the water extinction coefficient (estimated from turbidity), showing that this is an important parameters tuning the lake surface temperature.

Satellite remote sensing of water turbidity in Alqueva reservoir and implications on lake modelling

Potes, Miguel; Costa, Maria João; Salgado, Rui
Fonte: Copernicus Publications Publicador: Copernicus Publications
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.15%
The quality control and monitoring of surface freshwaters is crucial, since some of these water masses constitute essential renewable water resources for a variety of purposes. In addition, changes in the surface water composition may affect the physical properties of lake water, such as temperature, which in turn may impact the interactions of the water surface with the lower atmosphere. The use of satellite remote sensing to estimate the water turbidity of Alqueva reservoir, located in the south of Portugal, is explored. A validation study of the satellite derived water leaving spectral reflectance is firstly presented, using data taken during three field campaigns carried out during 2010 and early 2011. Secondly, an empirical algorithm to estimate lake water surface turbidity from the combination of in situ and satellite measurements is proposed. Finally, the importance of water turbidity on the surface energy balance is tested in the form of a study of the sensitivity of a lake model to the extinction coefficient of water (estimated from turbidity), showing that this is an important parameter that affects the lake surface temperature.

A satellite view of riverine turbidity plumes on the NE-E Brazilian coastal zone

Oliveira,Eduardo Negri de; Knoppers,Bastiaan Adriaan; Lorenzzetti,João Antônio; Medeiros,Paulo Ricardo Petter; Carneiro,Maria Eulália; Souza,Weber Friederichs Landim de
Fonte: Universidade de São Paulo, Instituto Oceanográfico Publicador: Universidade de São Paulo, Instituto Oceanográfico
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2012 EN
Relevância na Pesquisa
37.15%
Turbidity plumes of São Francisco, Caravelas, Doce, and Paraiba do Sul river systems, located along the NE/E Brazilian coast, are analyzed for their dispersal patterns of Total Suspended Solids (TSS) concentration using Landsat images and a logarithmic algorithm proposed by Tassan (1987) to convert satellite reflectance values to TSS. The TSS results obtained were compared to in situ collected TSS data. The analysis of the satellite image data set revealed that each river system exhibits a distinct turbidity plume dispersal pattern. The behavior, dimension and degree of turbidity of the São Francisco River plume have been greatly altered by the construction of a cascade of hydroelectric dam reservoirs in its hydrological basin. The plume has lost its typical unimodal seasonal pattern of material dispersion and its turbidity has decreased due to the regulation of river flow by the dams and TSS retainance by the reservoirs. In contrast, the Doce and Paraíba do Sul river plumes are still subject to seasonal pulsations and show more turbid conditions than the SF plume, as dams are less numerous, set in the middle river sections and the natural river flow has been maintained. The Caravelas Coastal System river plume is restricted to near shore shallow waters dominated by resuspension processes. During austral spring and summer when NE-E winds prevail...

The cause of turbidity in lyophilised plasmas and its effects on coagulation tests.

Hirst, C. F.; Poller, L.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1992 EN
Relevância na Pesquisa
27.27%
AIMS: To investigate the cause of turbidity in reconstituted lyophilised plasmas and to determine its effect on coagulometers. METHODS: The turbidities of 20 normal plasmas and 16 reconstituted lyophilised plasmas were determined by comparing a 1 in 4 dilution in distilled water with a standard suspension in an Aminco Fluorocolorimeter (American Instrument Co) in nephelometric mode. The turbidities of five other plasmas were determined before and after lyophilisation. The turbid components of fresh and reconstituted lyophilised plasmas were studied using electron microscopy. The effects of turbidity on five types of coagulometer were determined by adding varying concentrations of a turbidity enhancing material. RESULTS: Reconstituted lyophilised plasmas were more turbid than normal plasmas, because of agglomerated liposomes. Serum depleted of chylomicrons and very low density lipoproteins was not rendered more turbid by lyophilisation. Three out of five types of automated coagulometer tested gave activated partial thromboplastin times which were appreciably affected by plasma turbidity. One of the instruments was unable to detect a clot in a moderately turbid plasma. A second instrument gave results which were significantly affected by turbidity. Turbidity of the substrate plasma did not affect specific factor VIII assays in two types of coagulometer. CONCLUSIONS: Lyophilisation of plasma induces turbidity due to the agglomeration of lipids. Such turbidity can affect the results of coagulation tests. Suppliers of lyophilised plasmas should be aware of this problem.

Collagen I Self-Assembly: Revealing the Developing Structures that Generate Turbidity

Zhu, Jieling; Kaufman, Laura J.
Fonte: The Biophysical Society Publicador: The Biophysical Society
Tipo: Artigo de Revista Científica
Publicado em 15/04/2014 EN
Relevância na Pesquisa
27.3%
Type I collagen gels are routinely used in biophysical studies and bioengineering applications. The structural and mechanical properties of these fibrillar matrices depend on the conditions under which collagen fibrillogenesis proceeds, and developing a fuller understanding of this process will enhance control over gel properties. Turbidity measurements have long been the method of choice for monitoring developing gels, whereas imaging methods are regularly used to visualize fully developed gels. In this study, turbidity and confocal reflectance microscopy (CRM) were simultaneously employed to track collagen fibrillogenesis and reconcile the information reported by the two techniques, with confocal fluorescence microscopy (CFM) used to supplement information about early events in fibrillogenesis. Time-lapse images of 0.5 mg/ml, 1.0 mg/ml, and 2.0 mg/ml acid-solubilized collagen I gels forming at 27°C, 32°C, and 37°C were collected. It was found that in situ turbidity measured in a scanning transmittance configuration was interchangeable with traditional turbidity measurements using a spectrophotometer. CRM and CFM were employed to reveal the structures responsible for the turbidity that develops during collagen self-assembly. Information from CRM and transmittance images was collapsed into straightforward single variables; total intensity in CRM images tracked turbidity development closely for all collagen gels investigated...

Hyperspectral Sensing for Turbid Water Quality Monitoring in Freshwater Rivers: Empirical Relationship between Reflectance and Turbidity and Total Solids

Wu, Jiunn-Lin; Ho, Chung-Ru; Huang, Chia-Ching; Srivastav, Arun Lal; Tzeng, Jing-Hua; Lin, Yao-Tung
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 28/11/2014 EN
Relevância na Pesquisa
27.3%
Total suspended solid (TSS) is an important water quality parameter. This study was conducted to test the feasibility of the band combination of hyperspectral sensing for inland turbid water monitoring in Taiwan. The field spectral reflectance in the Wu river basin of Taiwan was measured with a spectroradiometer; the water samples were collected from the different sites of the Wu river basin and some water quality parameters were analyzed on the sites (in situ) as well as brought to the laboratory for further analysis. To obtain the data set for this study, 160 in situ sample observations were carried out during campaigns from August to December, 2005. The water quality results were correlated with the reflectivity to determine the spectral characteristics and their relationship with turbidity and TSS. Furthermore, multiple-regression (MR) and artificial neural network (ANN) were used to model the transformation function between TSS concentration and turbidity levels of stream water, and the radiance measured by the spectroradiometer. The value of the turbidity and TSS correlation coefficient was 0.766, which implies that turbidity is significantly related to TSS in the Wu river basin. The results indicated that TSS and turbidity are positively correlated in a significant way across the entire spectrum...

Turbidity interferes with foraging success of visual but not chemosensory predators

Lunt, Jessica; Smee, Delbert L.
Fonte: PeerJ Inc. Publicador: PeerJ Inc.
Tipo: Artigo de Revista Científica
Publicado em 08/09/2015 EN
Relevância na Pesquisa
27.3%
Predation can significantly affect prey populations and communities, but predator effects can be attenuated when abiotic conditions interfere with foraging activities. In estuarine communities, turbidity can affect species richness and abundance and is changing in many areas because of coastal development. Many fish species are less efficient foragers in turbid waters, and previous research revealed that in elevated turbidity, fish are less abundant whereas crabs and shrimp are more abundant. We hypothesized that turbidity altered predatory interactions in estuaries by interfering with visually-foraging predators and prey but not with organisms relying on chemoreception. We measured the effects of turbidity on the predation rates of two model predators: a visual predator (pinfish, Lagodon rhomboides) and a chemosensory predator (blue crabs, Callinectes sapidus) in clear and turbid water (0 and ∼100 nephelometric turbidity units). Feeding assays were conducted with two prey items, mud crabs (Panopeus spp.) that rely heavily on chemoreception to detect predators, and brown shrimp (Farfantepenaus aztecus) that use both chemical and visual cues for predator detection. Because turbidity reduced pinfish foraging on both mud crabs and shrimp...

Flotação por ar dissolvido na clarificação de águas com baixa turbidez utilizando sulfato de alumínio e sementes de Moringa oleifera como coagulantes; Dissolved air Flotation , for clarifying water with low turbidity using aluminum sulphate and Moringa oleifera seeds as coagulants

Lêdo, Patrícia Guilhermina da Silva
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia Química; Pesquisa e Desenvolvimento de Tecnologias Regionais Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia Química; Pesquisa e Desenvolvimento de Tecnologias Regionais
Tipo: Tese de Doutorado Formato: application/pdf
POR
Relevância na Pesquisa
37.27%
This work aims to investigate the process of Dissolved air Flotation (DAF) for clarifying water samples with low turbidity using aluminum sulphate and Moringa oleifera seeds as coagulants. The experimental procedure was carried out in a bench scale flotation unit. The influences on the pre-treatment conditions (coagulant dosage and flocculation time) and flotation parameters (superficial application rate and recirculation rate) were evaluated considering the efficiency of the process. The efficiency was evaluated by determining the turbidity of the untreated and treated water samples. The results obtained showed that turbidity reduction can be obtained very efficiently by using DAF and the latter coagulant in low turbidity water. Using aluminum sulphate in pH´s 5.0 and 6.0 better efficiencies were obtained with low concentrations (15 mg/L), achieving values of 92% of turbidity reduction. In the case of use of Moringa oleifera better efficiencies of reduction of turbidity were reported when using a concentration of 50 mg/L in all range of pH´s, achieving 86% of reduction. The zeta potential was also determined, in an attempt to aid comprehension of the coagulation mechanisms involved. The coagulation mechanisms with Moringa oleifera seeds were shown to be adsorption and charge neutralization...

Turbidity-based erosion estimation in a catchment in South Australia

Sun, H.; Cornish, P.; Daniell, T.
Fonte: Elsevier Science BV Publicador: Elsevier Science BV
Tipo: Artigo de Revista Científica
Publicado em //2001 EN
Relevância na Pesquisa
37.15%
An erosion estimation technique was developed in this study based on turbidity and sediment sampling data in a small catchment in South Australia. Several data sets, derived from the time sequence in which the data were collected, were used to develop a number of turbidity and suspended sediment relationships. These relationships were then used to estimate erosion from the catchment. The variability in sediment load estimation using different relationships, and how these relationships impacted on load estimation, were analyzed in detail. The study estimates erosion on a storm basis using detailed sediment sampling and turbidity data. Storm sediment loads were then accumulated to derive annual load, which distinguishes this study from volume based sediment studies. The study found that large storms dominate erosion in the catchment, and erosion rate depends more on peak storm flow than other hydrological variables. A relatively low annual erosion rate from the catchment was found, which is consistent with studies in other Australian catchments. The study found that, to establish a sound relationship between suspended sediment and turbidity for a catchment, it requires extensive data collection of large as well as small storms at short time intervals...

Short-term variability of bacterioplankton in the maximum turbidity zone in the Paranaguá Bay, Southern Brazil, and its relationship with environmental variables

Ribeiro,Catherine Gérikas; Kolm,Hedda Elisabeth; Costa Machado,Eunice da
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2011 EN
Relevância na Pesquisa
36.84%
In this work, the density of bacterioplankton, bacterial biomass and environmental variables were monitored in two seasons (summer and winter), two times each month (spring tide and neap tide sampling), over a 12 h period, comprising a tidal cycle (semidiurnal), from subsurface and bottom waters, in a fixed station in the Estuarine Turbidity Maximum Zone (ETMZ) of Paranaguá Bay, Brazil. The data were treated with multivariate analyses methods in order to indentify the key controlling factors of the bacterial community dynamics. The microbial community seemed to be structured by a close relationship with the nutrients concentration, mainly by total phosphorous and nitrate. Regardless of variations throughout the tidal cycles, free-living bacteria had a dominant role on the Paranaguá's Bay ETMZ.

Desempenho de sistemas de dupla filtração no tratamento de água com turbidez elevada; Evaluation of double filtration systems for high turbidity water treatment

Di Bernardo, Angela Silva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 08/07/2004 PT
Relevância na Pesquisa
37.2%
A dupla filtração pode ser considerada como uma das mais promissoras tecnologias para tratamento de água, estimando-se que grande parte das necessidades de tratamento poderiam ser satisfeitas com o uso desta tecnologia. Alguns aspectos ainda não devidamente esclarecidos até o presente sobre esta tecnologia estão relacionados ao tratamento de água com turbidez elevada. Com a montagem e operação de uma instalação piloto, constituída de dois sistemas de dupla filtração (sistema 1: filtro ascendente de areia grossa e filtro descendente de areia e sistema 2: filtro ascendente de pedregulho e filtro descendente de areia), foi realizada uma investigação experimental com águas de estudo preparadas com caulinita (água tipo I com turbidez em torno de 100 uT e água tipo II com turbidez em torno de 300 uT). A coagulação foi realizada com o sulfato de alumínio, sem o uso de alcalinizante ou de acidificante, para que resultasse potencial zeta próximo de zero. A operação de ambos os sistemas foi efetuada com e sem descargas de fundo intermediárias nos filtros ascendentes, e foram variadas as taxas de filtração em ambos os filtros (de 120 a 240 m³/m².d nos filtros ascendentes e de 180 a 300 m³/m².d nos filtros descendentes). Concluiu-se principalmente que os dois sistemas foram capazes de produzir água filtrada com turbidez consistentemente menor que 0...

A satellite view of riverine turbidity plumes on the NE-E Brazilian coastal zone

Oliveira, Eduardo Negri de; Knoppers, Bastiaan Adriaan; Lorenzzetti, João Antônio; Medeiros, Paulo Ricardo Petter; Carneiro, Maria Eulália; Souza, Weber Friederichs Landim de
Fonte: Universidade de São Paulo. Instituto Oceanográfico Publicador: Universidade de São Paulo. Instituto Oceanográfico
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 01/01/2012 ENG
Relevância na Pesquisa
37.15%
Turbidity plumes of São Francisco, Caravelas, Doce, and Paraiba do Sul river systems, located along the NE/E Brazilian coast, are analyzed for their dispersal patterns of Total Suspended Solids (TSS) concentration using Landsat images and a logarithmic algorithm proposed by Tassan (1987) to convert satellite reflectance values to TSS. The TSS results obtained were compared to in situ collected TSS data. The analysis of the satellite image data set revealed that each river system exhibits a distinct turbidity plume dispersal pattern. The behavior, dimension and degree of turbidity of the São Francisco River plume have been greatly altered by the construction of a cascade of hydroelectric dam reservoirs in its hydrological basin. The plume has lost its typical unimodal seasonal pattern of material dispersion and its turbidity has decreased due to the regulation of river flow by the dams and TSS retainance by the reservoirs. In contrast, the Doce and Paraíba do Sul river plumes are still subject to seasonal pulsations and show more turbid conditions than the SF plume, as dams are less numerous, set in the middle river sections and the natural river flow has been maintained. The Caravelas Coastal System river plume is restricted to near shore shallow waters dominated by resuspension processes. During austral spring and summer when NE-E winds prevail...

THE USE OF TURBIDITY MEASURES IN THE QUANTIFICATION OF SOLID MOVEMENT BY HIDRYC VEHICULATION IN THE BASINS OF THE RIVERS ANTA GORDA, BRINCO, COXILHA RICA AND JIRAU IN THE SOUTHWEST OF, COXILHA RICA PARANÁ; UTILIZAÇÃO DE MEDIDAS DE TURBIDEZ NA QUANTIFICAÇÃO DA MOVIMENTAÇÃO DE SÓLIDOS POR VEICULAÇÃO HÍDRICA NAS BACIAS DOS RIOS ANTA GORDA, BRINCO, COXILHA RICA E JIRAU – SUDOESTE DO ESTADO DO PARANÁ

Tomazoni, Julio Caetano; Mantovani, Luiz Eduardo; Bittencourt, André Virmond Lima; da Rosa Filho, Ernani Francisco
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Artigo Avaliado pelos Pares Formato: application/pdf
Publicado em 25/09/2006 POR
Relevância na Pesquisa
36.84%
This paper shows a factor of turbidity conversion in NTU for concentration of suspended particled material in mg/L. Optimizations were made in order to get better results in terms of laboratory and field research, propitiating a conversion factor closer to the reality of the concentration conditions of particled material in natural hydric environment in the Southwest of Paraná. The research was developed using sample data collected from fluvial metric-sediment stations, data from samples with particled material added and data from historical rescue of particled material analyses carried out by Sanepar from 1984 up to 2000.; Este trabalho demonstra um fator de conversão de turbidez em NTU para concentração de material particulado suspenso em mg/L. Otimizações foram feitas para que se conseguisse melhores resultados em termos de pesquisa de campo e de laboratório, propiciando um fator de conversão mais próximo da realidade das condições de concentração de material particulado em ambiente hídrico natural do Sudoeste do Estado do Paraná. A pesquisa foi desenvolvida utilizando dados de amostras coletadas em estações flúviosedimentométricas, dados originários de amostras com adição de material particulado e dados originários de resgate histórico de análises de material particulado efetuadas pela Sanepar de 1984 até 2000.

Chlorophyll a and turbidity patterns over coral reefs systems of La Parguera Natural Reserve,Puerto Rico

Otero,Ernesto; Carbery,Kelly K
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2005 EN
Relevância na Pesquisa
37.15%
Studies of temporal and spatial changes in phytoplankton biomass and turbidity provide essential information on coral reef ecosystem function and health.Fluctuation of phytoplankton biomass responds to several factors including nutrient inputs,both anthropogenic and natural,while turbidity is mostly affected by sediment resuspension or transport from terrestrial systems.These parameters can be used as sentinels of significant environmental factors "modifying "coral reef systems.A chlorophyll a concentration (Chl a )and turbidity (Turb)in situ logger was installed at 10 stations from June 4 to July 7,2003 in La Parguera Natural Reserve (Southwestern Puerto Rico)to assess short-term temporal and geographic variation in patterns of phytoplankton biomass and turbidity at pre-selected sites as part of an interdisciplinary long-term study.Average station Chl a variation was 0.17-1.12 µg l -1 and 0.2-23.4 NTU for Turb.Results indicate that the western near-coastal stations had higher levels of Turb and Chl a .The easternmost mid shelf station,Romero reef,was similar to coastal stations probably due to nutrient and suspended sediment inputs from a source external to our study area to the east,Guánica Bay.Comparisons between different sampling days indicate significant differences between days for most stations suggesting that one-time discrete sampling may not be representative of average water column conditions and illustrate the dynamic nature of coral reef systems.Further work is warranted to assess seasonal changes that integrate short-term (daily)variability in both Turb and Chl a .

Evaluation of the electro-coagulation process for the removal of turbidity of river water, wastewater and pond water

Pérez-Sicairos,S.; Morales-Cuevas,J.B.; Félix-Navarro,R.M.; Hernández-Calderón,O.M.
Fonte: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería Publicador: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2011 EN
Relevância na Pesquisa
37.08%
In this work, the removal of water turbidity was studied from three sources: Tamazula River, the Degremont Wastewater Treatment Plant and a pond of a botanical garden in the region of Culiacan, Sinaloa. For this purpose, parallel plate and continuous flow electrochemical reactors were constructed, both with perforated plate aluminum anodes and iron mesh cathodes, for the application of electro-coagulation. The process variables studied were the applied current and the concentration of supporting electrolyte, in the case of parallel plate reactor and also the volumetric flow rate, in the case of continuous flow reactor. According to the results, it is possible to eliminate the turbidity of the Tamazula river water with this process, achieving compliance with the official Mexican standards under the conditions studied. The general conclusion is that the electro-coagulation process has a great potential for application in turbidity removal for treatment of the three types of water sources used.

Turbidity removal: gravel and charcoal as roughing filtration media

Nkwonta,OI; Olufayo,OA; Ochieng,GM; Adeyemo,JA; Otieno,FAO
Fonte: South African Journal of Science Publicador: South African Journal of Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2010 EN
Relevância na Pesquisa
37.08%
Roughing filtration is an important pre-treatment process for wastewater, because it efficiently separates fine solid particles over prolonged periods, without the addition of chemicals. For this study, a pilot plant was designed at Delmas Coal Mine in the Mpumalanga province of South Africa. The design and sizing of the pilot plant was guided by Wegelin's design criteria. Gravel was used as a control medium because it is one of the most commonly used roughing filter media and because it was used in developing the criteria. We compared the performance of gravel as a filter medium to that of another locally available material, charcoal, for the removal of turbidity in wastewater. The pilot plant was monitored continuously for 90 days from commissioning until the end of the project. The overall performance of the roughing filter in turbidity removal, using gravel or charcoal, was considered efficient for the pre-treatment of waste water. Charcoal performed slightly better than gravel as a filter medium for the removal of turbidity, possibly because charcoal has a slightly higher specific surface area and porosity than gravel, which could enhance sedimentation and other filtration processes, such as adsorption, respectively.

Interplay of factors involving chlorine dose, turbidity flow capacity and pH on microbial quality of drinking water in small water treatment plants

Obi,CL; Igumbor,JO; Momba,MNB; Samie,A
Fonte: Water SA Publicador: Water SA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2008 EN
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In an endeavour to ascertain the interplay of factors involving chlorine dose, turbidity and flow capacity on microbial quality of drinking water in small water treatment plants (SWTPs), data from a previous study were analysed. The findings showed that most of the SWTPs were not producing water of safe microbial quality. Fifty one percent (51%) and seventy three (73%) of the SWTPs were below the stipulated limits for residual chlorine in final water and water at the point of use respectively. Current flow capacity was a major determinant of the microbial water quality indicators but no association was found between the dose of chlorine used for water treatment and the microbial water quality indicators. However, a combination of the amount of chlorine dose used up during treatment, flow capacity and change in turbidity contributed to about 65% of the amount of heterotrophic plate counts removed from raw water. Current flow capacity contributed less than 14% of the variation in chlorine dose used in water treatment at the plants. Turbidity tended to correlate and contribute more to the prediction of total coliform counts while faecal coliform counts were determined by current flow capacity and conductivity. Treatment plants with current flow capacity of over 50 Mℓ/d tended to be more efficient in heterotrophic plate count removal. In conclusion...