Application of Nanofiltration to the Treatment of Acid mine Drainage Waters

This study investigated the separation of uranium and other elements in high concentrations from acid mine waters at Caldas Uranium Mining, in the southeast of Brazil, using nanofiltration membranes. Nanofiltrarion is widely used in water treatment due to the lower energy requirements and higher yields than reverse osmosis. Separation characteristics are dependent on both the molecular size and charge of the dissolved species in the feed solution as well as membrane properties. In this investigation the potential of nanofiltration to removed dissolved species like uranium from acid mine water drainage was measured. Two composite aromatic polyamide commercially membranes of FilmTec/Dow were tested and it found that uranium rejections of greater than 90% and also showed potential for the separation of aluminum and manganese

Desenvolvimento de processos cromatográficos para retenção de amônia em água produzida- relatório final

A extração do petróleo em áreas offshore é, em geral, acompanhada de água de formação, originária do reservatório. Esta água tem características oleosas com um alto teor de sais o que constitui um sério problema ambiental. O nível de concentração de amônia nesta água é superior ao limite máximo permitido para descarte. A principal dificuldade na remoção de amônia da água produzida é o alto nível de íons sódio e a presença de muitos outros íons interferentes encontrados nesta água. Este relatório apresenta a consolidação do estudo da remoção de amônia de água produzida utilizando zeólitas e adsorventes comerciais

The program for biodiversity research in Brazil: The role of regional networks for biodiversity knowledge, dissemination, and conservation

The Program for Biodiversity Research (PPBio) is an innovative program designed to integrate all biodiversity research stakeholders. Operating since 2004, it has installed long-term ecological research sites throughout Brazil and its logic has been applied in some other southern-hemisphere countries. The program supports all aspects of research necessary to understand biodiversity and the processes that affect it. There are presently 161 sampling sites (see some of them at Supplementary Appendix), most of which use a standardized methodology that allows comparisons across biomes and through time. To date, there are about 1200 publications associated with PPBio that cover topics ranging from natural history to genetics and species distributions. Most of the field data and metadata are available through PPBio web sites or DataONE. Metadata is available for researchers that intend to explore the different faces of Brazilian biodiversity spatio-temporal variation, as well as for managers intending to improve conservation strategies. The Program also fostered, directly and indirectly, local technical capacity building, and supported the training of hundreds of undergraduate and graduate students. The main challenge is maintaining the long-term funding necessary to understand biodiversity patterns and processes under pressure from global environmental changes

Influência das condições reacionais nas características de copolímeros de metacrilato de metila e divinilbenzeno obtidos por polimerização em suspensão Influence from the reaction conditions on the characteristics of methyl methacrylate-divinylbenzene copolymers obtained by suspension polymerization

Foram sintetizados copolímeros esféricos e porosos à base de metacrilato de metila e divinilbenzeno através de polimerização em suspensão aquosa utilizando metil-etil-cetona (MEK) e ciclo-hexano (CH) como diluentes. Diferentes estruturas morfológicas foram obtidas através da modificação dos parâmetros reacionais tais como teor de divinilbenzeno e razão MEK/CH. Os copolímeros foram caracterizados por porosimetria de mercúrio, análise de área específica, densidade aparente e microscopia ótica. Foram obtidas estruturas macroporosas com os teores mais altos do DVB e do diluente não-solvatante (CH).Spherical and porous copolymers based on methyl methacrylate and divinylbenzene were synthesized by aqueous suspension polymerization using methyl-ethyl-ketone (MEK) and cyclohexane (CH) as diluents. Different morphological structures were obtained by modifying the reaction parameters, such as divinylbenzene content and MEK/CH ratio. The copolymers were characterized by several techniques: mercury porosimetry, specific superficial area analyzer, apparent density and optical microcopy. Macroporous structures were obtained when using high content of DVB and of nonsolvatant diluent (CH)

Copolímeros de estireno-divinilbenzeno impregnados com agentes complexantes organofosforados para separação de terras raras Styrene-divinylbenzene copolymers loaded with organophosphorus chelating agents for rare earths separation

RESUMO: Copolímeros de estireno-divinilbenzeno para aplicação em cromatografia de extração foram sintetizados em presença de agentes complexantes seletivos para terras raras, o fosfato monoácido de bis(2-etil-hexila), DEHPA e o 2-etil-hexil fosfonato monoácido de 2-etil-hexila, EHEHPA. Os copolímeros foram preparados através de polimerização em suspensão utilizando como diluentes os agentes complexantes puros ou combinados com o solvente tolueno (TOL). A influência das condições de síntese, tais como: a razão agente complexante/TOL; o grau de diluição dos monômeros e o teor de divinilbenzeno, na estrutura porosa dos copolímeros foi investigada através de suas características físicas tais como densidade aparente, volume de poros fixos, área específica e através de microscopia ótica e eletrônica de varredura. Os copolímeros foram avaliados em relação ao processo de separação de terras raras. Assim foram determinadas a capacidade total e a cinética de complexação em relação ao íon gadolínio. O teor de agente complexante impregnado em cada suporte foi função da quantidade do agente complexante nas misturas. Foi otimizada a quantidade máxima do agente complexante que pode ser utilizada na síntese, de modo a obter suportes com alta capacidade de complexação, sem o comprometimento de sua resistência mecânica. A capacidade total de complexação variou com a quantidade de agente complexante impregnado no suporte e a cinética de complexação variou principalmente com o diâmetro médio de poros, pois este determina a velocidade de difusão dos íons no suporte.ABSTRACT: Styrene-divinylbenzene copolymers used in extraction chromatography were synthesized in presence of selective chelating agents for rare earths: DEHPA, bis(2-ethylhexyl) phosphoric acid, and EHEHPA, bis(2-ethylhexyl) phosphonic acid. The copolymers were prepared by suspension polymerization technique using the pure chelating agents and its mixture with toluene (TOL) as diluents. The influence of synthesis conditions such as chelating agent/TOL ratios, dilution degree of monomers and amount of DVB on the porous structure of the copolymers were studied. The porous structure was characterized by the apparent density, fixed pore volume, surface area and by optical and scanning electron microscopy. The performance of the copolymers in the separation process of rare earths was evaluated. The total chelating capacity of each copolymer and the chelating kinetics in relation to gadolinium ion were determined. The chelating agent content of the copolymers depended on the amount of chelating agents employed in the synthesis. The highest amount of chelating agent that can be used in the synthesis in order to produce copolymers with high chelating capacity and good mechanical properties was determined. The total chelating capacity varied with the content of the chelating agents in the copolymer and the chelating kinetics was dependent mainly on the pore diameter, because this parameter determines the diffusion rate of the ions through the copolymer structure

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved

Adaptation of the Wound Healing Questionnaire universal-reporter outcome measure for use in global surgery trials (TALON-1 study): mixed-methods study and Rasch analysis

BackgroundThe Bluebelle Wound Healing Questionnaire (WHQ) is a universal-reporter outcome measure developed in the UK for remote detection of surgical-site infection after abdominal surgery. This study aimed to explore cross-cultural equivalence, acceptability, and content validity of the WHQ for use across low- and middle-income countries, and to make recommendations for its adaptation.MethodsThis was a mixed-methods study within a trial (SWAT) embedded in an international randomized trial, conducted according to best practice guidelines, and co-produced with community and patient partners (TALON-1). Structured interviews and focus groups were used to gather data regarding cross-cultural, cross-contextual equivalence of the individual items and scale, and conduct a translatability assessment. Translation was completed into five languages in accordance with Mapi recommendations. Next, data from a prospective cohort (SWAT) were interpreted using Rasch analysis to explore scaling and measurement properties of the WHQ. Finally, qualitative and quantitative data were triangulated using a modified, exploratory, instrumental design model.ResultsIn the qualitative phase, 10 structured interviews and six focus groups took place with a total of 47 investigators across six countries. Themes related to comprehension, response mapping, retrieval, and judgement were identified with rich cross-cultural insights. In the quantitative phase, an exploratory Rasch model was fitted to data from 537 patients (369 excluding extremes). Owing to the number of extreme (floor) values, the overall level of power was low. The single WHQ scale satisfied tests of unidimensionality, indicating validity of the ordinal total WHQ score. There was significant overall model misfit of five items (5, 9, 14, 15, 16) and local dependency in 11 item pairs. The person separation index was estimated as 0.48 suggesting weak discrimination between classes, whereas Cronbach's α was high at 0.86. Triangulation of qualitative data with the Rasch analysis supported recommendations for cross-cultural adaptation of the WHQ items 1 (redness), 3 (clear fluid), 7 (deep wound opening), 10 (pain), 11 (fever), 15 (antibiotics), 16 (debridement), 18 (drainage), and 19 (reoperation). Changes to three item response categories (1, not at all; 2, a little; 3, a lot) were adopted for symptom items 1 to 10, and two categories (0, no; 1, yes) for item 11 (fever).ConclusionThis study made recommendations for cross-cultural adaptation of the WHQ for use in global surgical research and practice, using co-produced mixed-methods data from three continents. Translations are now available for implementation into remote wound assessment pathways