RESUMO
The current study had conducted the life cycle analysis (LCA) to assess the environmental impact of microalgal wastewater treatment via an integrated membrane bioreactor. The functional unit selected for this analysis was 1 kg of treated microalgal wastewater with contaminants eliminated by ultrafiltration membrane fabricated from recycled polyethylene terephthalate waste. Meanwhile, the applied system boundary in this study was distinguished based on two scenarios, namely, cradle-to-gate encompassed wastewater treatment only and cradle-to-cradle which included the reutilization of treated wastewater to cultivate microalgae again. The environmental impacts and hotspots associated with the different stages of the wastewater treatment process had clearly elucidated that membrane treatment had ensued the highest impact, followed by microalgal harvesting, and finally cultivation. Among the environmental impact categories, water-related impact was found to be prominent in the following series: freshwater ecotoxicity, freshwater eutrophication and marine ecotoxicity. Notably, the key performance indicator of all environmental impact, i.e., the global warming potential was found to be very much lower at 2.94 × 10-4 kg CO2 eq as opposed to other literatures reported on the LCA of wastewater treatments using membranes. Overall, this study had proffered insights into the environmental impact of microalgal wastewater treatment and its stimulus for sustainable wastewater management. The findings of this study can be instrumental in making informed decision for optimizing microalgal wastewater treatment and reutilization assisted by membrane technology with an ultimate goal of enhancing sustainability.
Assuntos
Membranas Artificiais , Microalgas , Polietilenotereftalatos , Ultrafiltração , Águas Residuárias , Polietilenotereftalatos/química , Microalgas/crescimento & desenvolvimento , Ultrafiltração/métodos , Águas Residuárias/química , Águas Residuárias/análise , Eliminação de Resíduos Líquidos/métodos , Meio Ambiente , Reatores Biológicos , ReciclagemRESUMO
Ultrafiltration (UF) is widely used in wastewater reclamation treatments. Conventional backwashing is usually performed at regular time intervals (10-120 min) with permeate and without the addition of chemicals. Chemical enhanced backwashing (CEB) is usually applied after 70-90 filtration cycles with added chemicals. These cleaning methods cause membrane fouling and require costly chemicals. Instead of conventional backwashing, we propose herein a new backwashing method involving backwashing the effluent with low doses of sodium hypochlorite (NaClO) named as BELN. The performance and cost of UF backwashing were investigated with Beijing wastewater reclamation treatment. The results showed that the transmembrane pressure (TMP) increased from 33.2 to 48.2 kPa during hydraulic backwashing after 80 filtration cycles but increased from 33.3 to 39.3 kPa during backwashing with a low NaClO content of 20 mg/L. It was also noticed that the hydraulic-irreversible fouling index decreased from 5.58 × 10-3 m2/L to 3.58 × 10-3 m2/L with the new method. According to the three-dimensional fluorescence excitation-emission (3D-EEM), the response increased from 11.9 to 15.2% with BELN. Protein-like material was identified as the main component causing membrane fouling by blocking the membrane pores. The results indicated that the low dosage of NaClO effectively stripped the fouling layer. Finally, based on an economic evaluation, the capacity of the UF process was increased from 76,959 to 109,133 m3/d with the new method. The amount of NaClO consumed for Beijing wastewater reclamation treatment was similarly compared with the conventional backwashing in per year under BELN. The new method has good potential for application.
Assuntos
Ultrafiltração , Purificação da Água , Ultrafiltração/métodos , Águas Residuárias , Membranas Artificiais , Filtração , Purificação da Água/métodosRESUMO
Tyrosinase inhibitors can alleviate the harm to the liver caused by tyrosinase. How to effectively screen out natural tyrosinase inhibitors becomes a focus. In this study, Isodon excisoides was first extracted with the ultrasound optimized by response surface methodology. Then, a method combined ultrafiltration with ultra-liquid chromatography mass spectrometry (UHPLC/MS) was built to screen and identify tyrosinase inhibitors. The binding energies of active ingredients to tyrosinase were calculated by molecular docking. The reliability of the results was validated by the IC50 of enzyme inhibition assay. As a result, the binding energies of 7 components including excisanin B, lasiokaurin, rabdophyllin G, rabdoserrin B, rabdosin D, rabdosinate and weisiensin were lower than that of resveratrol. It was indicated that these components had high tyrosinase inhibitory activity. The IC50 values of lasiokaurin and excisanin B were 177 and 142â µmol/mL, which were less than that of resveratrol (183â µmol/mL). It showed that this way was simple, rapid, reliable and effective, which provided a new strategy to screen natural bioactive compounds from plants.
Assuntos
Isodon , Monofenol Mono-Oxigenase , Simulação de Acoplamento Molecular , Cromatografia Líquida de Alta Pressão/métodos , Isodon/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Resveratrol , Ultrafiltração/métodos , Reprodutibilidade dos TestesRESUMO
The study aims to recover nitrogen from wastewater by employing ultrafiltration membrane in water reuse for agriculture purpose. To such aim, a new reclaimed water quality index (RWQI) is proposed and applied including an innovative protocol for its assessment. Specifically, the influence of filtration and backwashing times for an ultrafiltration system aimed to nutrient recovery has been analyzed. The final goal was to pin down the trade-off between operation costs and effluent quality. Results show that backwashing time play a crucial role in reducing the operation costs; indeed, low values (i.e., 0.5 min) lead to an increase in the number of required chemical cleanings and consequently operation costs (namely, up to 0.042 /m3). The compromise among effluent quality and operation costs has been obtained for 7 min and 1 min, filtration and backwashing, respectively.
Assuntos
Ultrafiltração , Purificação da Água , Membranas Artificiais , Nitrogênio , Nutrientes , Ultrafiltração/métodos , Eliminação de Resíduos Líquidos , Águas Residuárias , Purificação da Água/métodosRESUMO
Ultrafiltration (UF) membranes are considered a pre-treatment for brackish water reverse osmosis (BWRO) membranes because of the high rejection rate of particulates and the productivity of the final water quantity. This study presents the performance and membrane surface property analysis of UF membranes for commercial membrane manufacturers, and their structural strength and chemical resistance were evaluated. Moreover, the pilot-scale UF-BWRO process was operated for two months using real wastewater based on the results of this study. Although the overall properties were similar, the poly (ether-sulfone) UF membrane showed higher tensile strength than the polyvinylidene difluoride and polyacrylonitrile UF membranes. The UF membrane showed a high removal rate of particulates (over 90%) but low rejection rate of organic compounds, such as humic acid and sodium alginate (below 30%). After exposure to high concentrations of chemicals, the contact angle of the membranes was reduced by approximately 15% compared to that of the virgin membranes. In addition, despite the exposure to low-and high-concentration chemicals, UF membranes were relatively stable in terms of tensile strength. During the operation period of the pilot-scale UF-RO process, the UF membrane showed a high turbidity removal of over 93%, and the UF-BWRO process presented a high salt rejection of over 92%. The UF membrane showed potential for the pre-treatment of BWRO membranes.
Assuntos
Ultrafiltração , Purificação da Água , Membranas Artificiais , Osmose , Águas Salinas , Ultrafiltração/métodos , Águas Residuárias/análise , Purificação da Água/métodosAssuntos
Hiperemia/diagnóstico por imagem , Nefrologistas/educação , Testes Imediatos/normas , Ultrassonografia Doppler/métodos , Adulto , Pressão Atrial/fisiologia , Creatinina/sangue , Nefropatias Diabéticas/complicações , Taxa de Filtração Glomerular/fisiologia , Átrios do Coração/diagnóstico por imagem , Veias Hepáticas/diagnóstico por imagem , Veias Hepáticas/fisiopatologia , Humanos , Hiperemia/etiologia , Masculino , Testes Imediatos/estatística & dados numéricos , Veia Porta/diagnóstico por imagem , Veia Porta/fisiopatologia , Insuficiência Renal Crônica/classificação , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/etiologia , Índice de Gravidade de Doença , Ultrafiltração/métodosRESUMO
Background: Heart failure (HF) is a common, serious disease in the US and Europe. Patients with HF often require treatment for fluid overload, resulting in costly inpatient visits; however, limited evidence exists on the costs of alternative treatments. This study performed a cost-analysis of ultrafiltration (UF) vs diuretic therapy (DIUR-T) for patients with HF from the hospital perspective. Methods: The model used clinical data from the literature and hospital data from the Healthcare Cost and Utilization Project to follow a decision-analytic framework reflecting treatment decisions, probabilistic outcomes, and associated costs for treating patients with HF and hypervolemia with veno-venous UF or intravenous DIUR-T. A 90-day timeframe was considered to account for hospital readmissions beyond 30 days. Sensitivity and scenario analyses were performed to gauge the robustness of the results. Results: Although initial hospitalization costs were higher, fluid removal by UF reduced hospital readmission days, leading to cost savings of $3,975 (14.4%) at the 90-day follow-up (UF costs, $23,633; DIUR-T costs, $27,608). Conclusions: UF is a viable alternative to DIUR-T when treating fluid overload in HF patients because it reduces hospital readmission rates and durations, which substantially lowers costs over a 90-day period compared to DIUR-T.
Assuntos
Diuréticos/uso terapêutico , Insuficiência Cardíaca/terapia , Custos Hospitalares/estatística & dados numéricos , Modelos Econométricos , Ultrafiltração/métodos , Simulação por Computador , Técnicas de Apoio para a Decisão , Diuréticos/administração & dosagem , Diuréticos/efeitos adversos , Diuréticos/economia , Humanos , Injeções Intravenosas , Tempo de Internação/economia , Modelos Estatísticos , Método de Monte Carlo , Readmissão do Paciente/economia , Readmissão do Paciente/estatística & dados numéricos , Ultrafiltração/efeitos adversos , Ultrafiltração/economiaRESUMO
Quantitative screening for potential drug-protein binding is an essential step in developing novel metal-based anticancer drugs. ICP-MS approaches are at the core of this task; however, many applications lack in the capability of large-scale high-throughput screenings and proper validation. In this work, we critically discuss the analytical figures of merit and the potential method-based quantitative differences applying four different ICP-MS strategies to ex vivo drug-serum incubations. Two candidate drugs, more specifically, two Pt(IV) complexes with known differences of binding affinity towards serum proteins were selected. The study integrated centrifugal ultrafiltration followed by flow injection analysis, turbulent flow chromatography (TFC), and size exclusion chromatography (SEC), all combined with inductively coupled plasma-mass spectrometry (ICP-MS). As a novelty, for the first time, UHPLC SEC-ICP-MS was implemented to enable rapid protein separation to be performed within a few minutes at > 90% column recovery for protein adducts and small molecules. Graphical abstract Quantitative screening for potential drug-protein binding is an essential step in developingnovel metal-based anticancer drugs.
Assuntos
Antineoplásicos/metabolismo , Proteínas Sanguíneas/metabolismo , Compostos Organoplatínicos/metabolismo , Antineoplásicos/análise , Proteínas Sanguíneas/análise , Cromatografia em Gel/métodos , Cromatografia Líquida de Alta Pressão/métodos , Análise de Injeção de Fluxo/métodos , Humanos , Espectrometria de Massas/métodos , Metais/análise , Metais/metabolismo , Compostos Organoplatínicos/análise , Ligação Proteica , Ultrafiltração/métodosRESUMO
The purpose of this work was to study the ozonation of nanofiltration (NF) retentates of real municipal wastewater treatment plant (MWTP) effluents for removal of microcontaminants (MCs) and toxicity. MCs present in these effluents were monitored using LC-MS/MS. Acute and chronic toxicity was addressed with Daphnia magna, Vibrio fischeri and Selenastrum capricornutum. Up to 40 MCs were found, most of them in concentrations over 100ng/L. 90% degradation of the sum of MCs was the critical point of comparison. When the NF membrane system was applied to MWTP effluents, treatment of NF rejection needed 2.75-4.5g O3/m3,4.5g O3/m3, which is less than 50% of the ozone needed for direct treatment of MWTP effluent. Treatment time (lower than 11min) was not influenced by MCs concentration, at least in the range tested (25-190µg/L). It has been demonstrated that consumption of ozone increased with organic load and inorganic content of different real effluents. MCs were eliminated by ozonation but acute toxicity (against V. fischeri and D. magna) increased. Chronic toxicity results were different and contrary in D. magna and S. capricornutum, due to the generation of new transformation products more toxic to D. magna than the parent contaminants. S. capricornutum inhibition percentage decreased in all cases after ozonation treatment. According to these results, before ozonation is implemented in MWTPs for the removal of MCs, the transformation products must first be examined and the treatment time or ozone doses should be extended to complete degradation if necessary.
Assuntos
Recuperação e Remediação Ambiental/métodos , Ozônio/química , Ultrafiltração/métodos , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade , Aliivibrio fischeri/efeitos dos fármacos , Animais , Clorófitas/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Membranas Artificiais , Purificação da ÁguaRESUMO
Bacterial endotoxins, DNA, live viruses, and viral proteins derived from bacterial and baculovirus (BV) expression vectors employed in recombinant protein production contaminate the final product. Density gradient centrifugation is commonly used to partially purify oligomeric proteins, but impurities from the expression system still remain. We describe a simple and rapid ultrafiltration method for final purification of rotavirus VP6 oligomeric nanotubes and nanospheres. Contamination originating from the BV vector used in VP6 production was undetectable. The method is highly efficient, fast and inexpensive and can be used for a small-scale laboratory purification of VP6 protein to replace technically demanding multi-step chromatographic procedures.
Assuntos
Antígenos Virais/isolamento & purificação , Proteínas do Capsídeo/isolamento & purificação , Proteínas Recombinantes/isolamento & purificação , Ultrafiltração/métodos , Virologia/métodos , Análise Custo-Benefício , Complexos Multiproteicos/isolamento & purificação , Nanosferas , Nanotubos , Fatores de Tempo , Ultrafiltração/economia , Virologia/economiaRESUMO
This work assessed the potential of nanofiltration (NF) and reverse osmosis (RO) to treat acid streams contaminated with metals, such as effluent from the pressure oxidation process (POX) used in refractory gold ore processing. NF and RO were evaluated in terms of rejections of sulfuric acid and metals. Regarding NF, high sulfuric acid permeation (â¼100%), was observed, while metals were retained with high efficiencies (â¼90%), whereas RO led to high acid rejections (<88%) when conducted in pH values higher than 1. Thus, sequential use of NF and RO was proved to be a promising treatment for sulfuric acid solutions contaminated by metals, such as POX effluent. In this context, a purified acid stream could be recovered in NF permeate, which could be further concentrated in RO. Recovered acid stream could be reused in the gold ore processing or commercialized. A metal-enriched stream could be also recovered in NF retentate and transferred to a subsequent metal recovery stage. In addition, considering the high acid rejection obtained through the proposed system, RO permeate could be used as recycling water.
Assuntos
Osmose , Reciclagem , Ultrafiltração/métodos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Água/análise , Ouro , Resíduos Industriais , Metais/análise , Mineração , Ácidos Sulfúricos/análise , Eliminação de Resíduos Líquidos/instrumentação , Purificação da ÁguaRESUMO
Heart failure remains a major public health concern because of its high prevalence, morbidity, mortality, and financial burden. The poor clinical outcomes associated with acute decompensated heart failure, suboptimal efficacy and safety profile of conventional treatment regimens, and unsatisfactory experiences with the newer classes of pharmacologic therapy underlie the interest in the use of extracorporeal isolated ultrafiltration in this setting. In this article, selected mechanistic aspects of ultrafiltration therapy are briefly reviewed followed by a critical overview of the largest trials in this field. I will discuss the clinical relevance of renal dysfunction and decongestion as two commonly used end points of safety and efficacy in the ultrafiltration trials, with emphasis on the emerging pertinent notions that could challenge our conventional thinking. Finally, a number of practical recommendations (e.g., customization of ultrafiltration rates) are provided for ultrafiltration therapy in the setting of acute decompensated heart failure. Because of a paucity of evidence, universally accepted consensus guidelines cannot yet be generated. As such, when considering ultrafiltration therapy for acute decompensated heart failure, the likely benefits should be carefully balanced against the potential risks for an individual patient. A conceivable implication of the ultrafiltration trials is that collaborative heart failure programs benefiting from nephrology expertise and resources could improve the outcomes and reduce the cost.
Assuntos
Insuficiência Cardíaca/terapia , Rim/fisiopatologia , Ultrafiltração , Doença Aguda , Ensaios Clínicos como Assunto , Taxa de Filtração Glomerular , Humanos , Ultrafiltração/economia , Ultrafiltração/métodosRESUMO
This study used a range of treated water treatment works sludge options for the removal of phosphorus (P) from primary wastewater. These options included the application of ultrafiltration for recovery of the coagulant from the sludge. The treatment performance and whole life cost (WLC) of the various recovered coagulant (RC) configurations have been considered in relation to fresh ferric sulphate (FFS). Pre-treatment of the sludge with acid followed by removal of organic and particulate contaminants using a 2kD ultrafiltration membrane resulted in a reusable coagulant that closely matched the performance FFS. Unacidified RC showed 53% of the phosphorus removal efficiency of FFS, at a dose of 20 mg/L as Fe and a contact time of 90 min. A longer contact time of 8 h improved performance to 85% of FFS. P removal at the shorter contact time improved to 88% relative to FFS by pre-acidifying the sludge to pH 2, using an acid molar ratio of 5.2:1 mol H(+):Fe. Analysis of the removal of P showed that rapid phosphate precipitation accounted for >65% of removal with FFS. However, for the acidified RC a slower adsorption mechanism dominated; this was accelerated at a lower pH. A cost-benefit analysis showed that relative to dosing FFS and disposing waterworks sludge to land, the 20 year WLC was halved by transporting acidified or unacidified sludge up to 80 km for reuse in wastewater treatment. A maximum inter-site distance was determined to be 240 km above the current disposal route at current prices. Further savings could be made if longer contact times were available to allow greater P removal with unacidified RC.
Assuntos
Fósforo/isolamento & purificação , Ultrafiltração/métodos , Eliminação de Resíduos Líquidos/métodos , Análise Custo-Benefício , Compostos Férricos/química , Floculação , Fosfatos/química , Esgotos , Eliminação de Resíduos Líquidos/economia , Purificação da Água/métodosRESUMO
Binding affinity of a small molecule drug candidate to a therapeutically relevant biomolecular target is regarded the first determinant of the candidate's efficacy. Although the ultrafiltration-LC/MS (UF-LC/MS) assay enables efficient ligand discovery for a specific target from a mixed pool of compounds, most previous analysis allowed for relative affinity ranking of different ligands. Moreover, the reliability of affinity measurement for multiple ligands with UF-LC/MS has hardly been strictly evaluated. In this study, we examined the accuracy of K(d) determination through UF-LC/MS by comparison with classical ITC measurement. A single-point K(d) calculation method was found to be suitable for affinity measurement of multiple ligands bound to the same target when binding competition is minimized. A second workflow based on analysis of the unbound fraction of compounds was then developed, which simplified sample preparation as well as warranted reliable ligand discovery. The new workflow implemented in a fragment mixture screen afforded rapid and sensitive detection of low-affinity ligands selectively bound to the RNA polymerase NS5B of hepatitis C virus. More importantly, ligand identification and affinity measurement for mixture-based fragment screens by UF-LC/MS were in good accordance with single ligand evaluation by conventional SPR analysis. This new approach is expected to become a valuable addition to the arsenal of high-throughput screening techniques for fragment-based drug discovery.
Assuntos
Antivirais/química , Antivirais/farmacologia , Descoberta de Drogas/métodos , Hepacivirus/metabolismo , Hepatite C/virologia , Proteínas não Estruturais Virais/metabolismo , Cromatografia Líquida/economia , Cromatografia Líquida/métodos , Descoberta de Drogas/economia , Hepacivirus/efeitos dos fármacos , Hepatite C/tratamento farmacológico , Ensaios de Triagem em Larga Escala/economia , Ensaios de Triagem em Larga Escala/métodos , Humanos , Ligantes , Espectrometria de Massas/economia , Espectrometria de Massas/métodos , Ligação Proteica , Reprodutibilidade dos Testes , Ultrafiltração/economia , Ultrafiltração/métodos , Fluxo de TrabalhoRESUMO
There could be several options a water treatment plant (WTP) can select from, if an improvement in treated water quality (WQ) is desired. This paper outlines a methodology to test a variety of approaches to accomplish pre-set goals as regards WQ, while adopting a triple bottom line approach. This approach, in a nutshell, takes into consideration economic, environmental and social aspects in decision-making. The methodology has been applied to the Stangasen WTP in the town of Oppegård in south-eastern Norway. Among the seven alternative approaches compared were the use, as coagulant, of five different dosages of granulated aluminium sulphate, liquid aluminium sulphate (48%) and liquid ferric chloride (40%). Using the set of weighting factors obtained from experts, it was determined that increasing the dosage of granulated aluminium sulphate by 20% over the current one would be the most sustainable option from a triple bottom line point of view.
Assuntos
Água Potável/química , Modelos Teóricos , Ultrafiltração/economia , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/economia , Purificação da Água/métodos , Algoritmos , Cidades , Simulação por Computador , Tomada de Decisões , Meio Ambiente , Noruega , Avaliação de Programas e Projetos de Saúde , Ultrafiltração/métodosRESUMO
The textile industries hold an important position in the global industrial arena because of their undeniable contributions to basic human needs satisfaction and to the world economy. These industries are however major consumers of water, dyes and other toxic chemicals. The effluents generated from each processing step comprise substantial quantities of unutilized resources. The effluents if discharged without prior treatment become potential sources of pollution due to their several deleterious effects on the environment. The treatment of heterogeneous textile effluents therefore demands the application of environmentally benign technology with appreciable quality water reclamation potential. These features can be observed in various innovative membrane based techniques. The present review paper thus elucidates the contributions of membrane technology towards textile effluent treatment and unexhausted raw materials recovery. The reuse possibilities of water recovered through membrane based techniques, such as ultrafiltration and nanofiltration in primary dye houses or auxiliary rinse vats have also been explored. Advantages and bottlenecks, such as membrane fouling associated with each of these techniques have also been highlighted. Additionally, several pragmatic models simulating transport mechanism across membranes have been documented. Finally, various accounts dealing with techno-economic evaluation of these membrane based textile wastewater treatment processes have been provided.
Assuntos
Resíduos Industriais/análise , Indústria Têxtil , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Água/química , Corantes/análise , Humanos , Modelos Teóricos , Papel , Ultrafiltração/métodosRESUMO
Attached growth processes for wastewater treatment have significantly been improved during recent years. Their application can be extended to sustainable municipal wastewater treatment in remote locations and in developing countries for the purpose of organic matter (biochemical oxygen demand, BOD) removal and pathogenic decontamination. The aim of this study is to assess selected packing media for biological trickling filters (BTFs) and to develop a simplified model for describing the capacity of BOD removal in BTFs. In this work, BTFs with four different media viz., rubber, polystyrene, plastic and stone have been investigated at two temperature ranges of 5-15°C and 25-35°C. The average removal of both chemical oxygen demand and BOD was higher than 80 and 90% at temperature ranges of 5-15 and 25-35°C, respectively. The geometric mean of faecal coliforms in BTF using polystyrene, plastic, rubber and stone as filter media was reduced by 4.3, 4.0, 5.8 and 5.4â log10, respectively, at a low temperature range of 5-15°C. At a higher temperature range of 25-35°C, the faecal coliform count was reduced by 3.97, 5.34, 5.36 and 4.37â log10 from polystyrene, plastic, rubber and stone media BTF, respectively. Simplified model was developed and used to estimate the optimal BOD loading rates (Bvd) for designing robust BTF systems, with appropriate filter media. It has been concluded that highly efficient BTFs can be designed using various filter media, which may be capable of treating organic loading rates of more than 3â kg BOD/m3 day. These types of BTFs can be applied for the BOD and microbial contaminants removal of wastewater for potential reuse in developing countries.
Assuntos
Ultrafiltração/instrumentação , Eliminação de Resíduos Líquidos/instrumentação , Águas Residuárias/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/instrumentação , Fenômenos Fisiológicos Bacterianos , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Simulação por Computador , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Modelos Biológicos , Ultrafiltração/métodos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Purificação da Água/métodosAssuntos
Participação do Paciente , Diálise Peritoneal/métodos , Ultrafiltração/métodos , Pesquisa Biomédica , Análise Custo-Benefício , Bases de Dados Factuais , Humanos , Satisfação do Paciente , Diálise Peritoneal/efeitos adversos , Diálise Peritoneal/economia , Estudos Retrospectivos , Medição de Risco , Espanha , Ultrafiltração/efeitos adversos , Ultrafiltração/economiaRESUMO
Certain nitrosamines in water are disinfection byproducts that are probable human carcinogens. Nitrosamines have diverse and complex precursors that include effluent organic matter, some anthropogenic chemicals, and natural (likely non-humic) substances. An easy and selective tool was first developed to characterize nitrosamine precursors in treated wastewaters, including different process effluents. This tool takes advantages of the polarity rapid assessment method (PRAM) and ultrafiltration (UF) (molecular weight distribution) to locate the fractions with the strongest contributions to the nitrosamine precursor pool in the effluent organic matter. Strong cation exchange (SCX) and C18 solid-phase extraction cartridges were used for their high selectivity for nitrosamine precursors. The details of PRAM operation, such as cartridge clean-up, capacity, pH influence, and quality control were included in this paper, as well as the main parameters of UF operation. Preliminary testing of the PRAM/UF method with effluents from one wastewater treatment plant gave very informative results. SCX retained 45-90% of the N-nitrosodimethylamine (NDMA) formation potential (FP)-a measure of the precursors-in secondary and tertiary wastewater effluents. These results are consistent with NDMA precursors likely having a positively charged amine group. C18 adsorbed 30-45% of the NDMAFP, which indicates that a substantial portion of these precursors were non-polar. The small molecular weight (MW) (<1 kDa) and large MW (>10 kDa) fractions obtained from UF were the primary contributors to NDMAFP. The combination of PRAM and UF brings important information on the characteristics of nitrosamine precursors in water with easy operation.
Assuntos
Dimetilnitrosamina/análise , Monitoramento Ambiental/métodos , Compostos Orgânicos/análise , Ultrafiltração/métodos , Águas Residuárias/análise , Poluentes Químicos da Água/análise , Extração em Fase SólidaRESUMO
AIM: Intravenous diuretics at relatively high doses are currently used for treating acute decompensated heart failure (ADHF). However, the existence of harmful side effects diuretic-related, such as electrolyte abnormalities, symptomatic hypotension and marked neuro-hormonal activation have led researchers to implement alternative therapeutic tools such as isolated ultrafiltration (IUF). METHODS: Our study aimed to compare intravenous diuretics vs. IUF as regards their respective efficacy and safety in ADHF patients through systematic review and meta-analysis of data derived from relevant randomized controlled trials. RESULTS: 6 studies grouping a total of 477 patients were included in the systematic review. By contrast, data from only three studies were pooled for the meta-analysis, because of different adopted outcomes or marked dissimilarities in the data presentation . Weight loss at 48 h was greater in IUF group compared to the diuretics group [weighted mean difference (WMD)=1.77 kg; 95%CI: 1.18-2.36 kg; P<0.001)]. Similarly, greater fluid loss at 48 h was found in IUF group in comparison with diuretics group (WMD=1.2 liters; 95%CI: 0.73-1.67 liters; P< 0.001). In contrast, the probability of exhibiting worsening renal function (WRF), i.e., increase in serum creatinine > 0.3 mg/dl at 48 hours, was similar to the one found in the diuretics group (OR=1.33; 95% CI: 0.81-2.16 P=0.26). CONCLUSION: On the basis of this meta-analysis, IUF induced greater weight loss and larger fluid removal compared to iv diuretics in ADHF patients, whereas the probability of developing WRF was not significantly different in the comparison between iv diuretics and IUF.