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1.
Sci Rep ; 10(1): 7688, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32376848

RESUMO

Online monitoring of algal biotechnological processes still requires development to support economic sustainability. In this work, fluorescence spectroscopy coupled with chemometric modelling is studied to monitor simultaneously several compounds of interest, such as chlorophyll and fatty acids, but also the biomass as a whole (cell concentration). Fluorescence excitation-emission matrices (EEM) were acquired in experiments where different environmental growing parameters were tested, namely light regime, temperature and nitrogen (replete or deplete medium). The prediction models developed have a high R2 for the validation data set for all five parameters monitored, specifically cell concentration (0.66), chlorophyll (0.78), and fatty acid as total (0.78), saturated (0.81) and unsaturated (0.74). Regression coefficient maps of the models show the importance of the pigment region for all outputs studied, and the protein-like fluorescence region for the cell concentration. These results demonstrate for the first time the potential of fluorescence spectroscopy for in vivo and real-time monitoring of these key performance parameters during Nannochloropsis oceanica cultivation.

2.
Int J Mol Sci ; 21(8)2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32331206

RESUMO

The unprecedently high CO2 levels in the atmosphere evoke the urgent need for development of technologies for mitigation of its emissions. Among the alternatives, the biocatalytic route has been claimed as one of the most promising. In the present work, the carbonic anhydrase from bovine erythrocytes (BCA) was employed as a model enzyme for structural studies in an aqueous phase at alkaline pH, which is typical of large-scale absorption processes under operation. Circular dichroism (CD) analysis revealed a high enzymatic stability at pH 10 with a prominent decrease of the melting temperature above this value. The CO2 absorption capacity of the aqueous solutions were assessed by online monitoring of pressure decay in a stainless-steel cell, which indicated a better performance at pH 10 with a kinetic rate increase of up to 43%, as compared to non-biocatalytic conditions. Even low enzyme concentrations (0.2 mg g-1) proved to be sufficient to improve the overall CO2 capture process performance. The enzyme-enhanced approach of CO2 capture presents a high potential and should be further studied.

3.
J Environ Manage ; 261: 110229, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32148299

RESUMO

Technologies for water recycling within oil refineries have been gaining interest at an extensive rate due to the large volume of wastewater generated, high dependency of water and the progressive scarcity of this valuable resource. Phenols are part of a specific class of organic pollutants that have been contributing to a low-quality effluent in oil refineries due to their hazardous nature and strict environmental legislation associated. The reuse of stripped sour water within refineries is often blocked due to its rich phenolic content. This study evaluates the retention of phenols in refinery wastewater through reverse osmosis (RO) at its major source of emission, for water reclamation. The RO membrane selected exhibited rejections of up to 98% of phenols and 99% of both chemical oxygen demand (COD) and total organic carbon (TOC). Permeate quality remained intact despite flux decline caused by phenolic and hydrocarbon adsorption when the oil content, in the feed, reached 771 ppm. The effluent's low conductivity due to lack of salts led to minor osmotic pressure differences (less than 2.5 bar at a volume concentration factor of 3), therefore, showing appealing performances of reverse osmosis filtration. Characterization of all permeates obtained from cross-flow filtration experiments showed COD levels in line with water reuse quality standards for make-up water in cooling processes.


Assuntos
Eliminação de Resíduos Líquidos , Purificação da Água , Filtração , Hidrocarbonetos , Membranas Artificiais , Osmose , Pressão Osmótica , Fenóis , Águas Residuárias
4.
Bioresour Technol ; 297: 122509, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31812914

RESUMO

Dunaliella salina is well-known for its high content in carotenoids and glycerol. Nevertheless, Dunaliella salina has also a high content in lipids, including polar lipids, which are suitable for nutraceutical/cosmeceutical applications. This work proposes a sustainable process to maximise the potential of Dunaliella salina for the production of distinct fractions of carotenoids, glycerol, polar lipids and proteins, which may contribute to improve the revenues of the microalgae industry. In this work, extraction with non-hazardous solvents and organic solvent nanofiltration are integrated, in order to obtain added-value products and glycerol. Also, aiming to separate carotenoids from glycerides, a saponification process is proposed. High overall recoveries were obtained for carotenoids (85%), glycerol (86%), polar lipids (94%) and proteins (95%). In order to evaluate the profitability of the proposed biorefinery, an economic assessment was accomplished. Both CAPEX and OPEX (Capital and Operating expenditure) were calculated, likewise the Return of Investment (ROI).


Assuntos
Carotenoides , Microalgas , Glicerídeos , Glicerol , Lipídeos
5.
Molecules ; 24(24)2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31817756

RESUMO

This work described a new sustainable method for the fabrication of ceramic membranes with high photocatalytic activity, through a simple sol-gel route. The photocatalytic surfaces, prepared at low temperature and under solvent-free conditions, exhibited a narrow pore size distribution and homogeneity without cracks. These surfaces have shown a highly efficient and reproducible behavior for the degradation of methylene blue. Given their characterization results, the microfiltration photocatalytic membranes produced in this study using solvent-free conditions are expected to effectively retain microorganisms, such as bacteria and fungi that could then be inactivated by photocatalysis.


Assuntos
Fotoquímica/métodos , Solventes/química , Catálise , Azul de Metileno/química , Temperatura
6.
Food Chem ; 300: 125167, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31325747

RESUMO

Anthocyanin lipophilization emerged as an efficient technique to improve their chemical stability, liposolubility and antioxidant properties for novel technological applications. This work describes an efficient method for the synthesis of cyanidin-3-glucoside-fatty acid conjugate using a Candida antarctica lipase B-rich extract, without further purification and retained in a porous membrane. Due to the enzyme retention within the membrane structure it was possible to improve the yield of the lipophilization reaction by 2.5-fold as well as obtaining the product in a shorter period of time comparing with its free form. Furthermore, the membrane retention allowed for enzyme reusability, since the same conversion yield was obtained in three consecutive reaction cycles.


Assuntos
Antocianinas/metabolismo , Ácidos Graxos/metabolismo , Proteínas Fúngicas/metabolismo , Glucosídeos/metabolismo , Lipase/metabolismo , Antocianinas/química , Antioxidantes/química , Enzimas Imobilizadas/metabolismo , Glucosídeos/química
7.
ACS Appl Mater Interfaces ; 11(23): 21239-21249, 2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31141340

RESUMO

This work shows the ability to reversibly modulate the hydrophilicity of the hydrogels doped with iron oxide nanoparticles (MNPs) in a noninvasive way when exposed to a cyclic variation of the intensity (ON/OFF) of an external magnetic field. A reversible switching of surface contact angles was observed for magnetic PVA hydrogels when exposed to consecutive variation of the magnetic field intensity between 0 and 0.08 T. Motivated by the magnetic dependence of the hydrophilicity of these hybrid hydrogels, the impact of the magnetic field on protein sorption was also evaluated. The noninvasive regulation of protein sorption-released mechanisms was achieved by ON/OFF magnetic field switches, suggesting the possible influence of magnetic-induced hydrogel shrinking effect and changes of surface wettability on protein sorption. The capacity to magnetically modulate surface wettability and protein sorption make these magnetic hydrogels promising candidates for development of functional devices for tissue engineering, drug release applications, or biosensor systems, where the control of protein sorption and mobility are essential steps to improve the efficiency of these processes.


Assuntos
Hidrogéis/química , Campos Magnéticos , Proteínas/química , Compostos Férricos/química , Nanopartículas/química
8.
Int J Mol Sci ; 20(1)2019 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-30621185

RESUMO

Profiled membranes (also known as corrugated membranes, micro-structured membranes, patterned membranes, membranes with designed topography or notched membranes) are gaining increasing academic and industrial attention and recognition as a viable alternative to flat membranes. So far, profiled ion exchange membranes have shown to significantly improve the performance of reverse electrodialysis (RED), and particularly, electrodialysis (ED) by eliminating the spacer shadow effect and by inducing hydrodynamic changes, leading to ion transport rate enhancement. The beneficial effects of profiled ion exchange membranes are strongly dependent on the shape of their profiles (corrugations/patterns) as well as on the flow rate and salts' concentration in the feed streams. The enormous degree of freedom to create new profile geometries offers an exciting opportunity to improve even more their performance. Additionally, the advent of new manufacturing methods in the membrane field, such as 3D printing, is anticipated to allow a faster and an easier way to create profiled membranes with different and complex geometries.


Assuntos
Membranas Artificiais , Diálise/métodos , Difusão , Divórcio , Impedância Elétrica , Filtração/métodos , Hidrodinâmica , Troca Iônica , Impressão Tridimensional , Salinidade
9.
Macromol Rapid Commun ; 40(2): e1800333, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30027594

RESUMO

This article presents the synthesis of poly(methacrylic acid)-b-poly(methyl methacrylate) diblock copolymer via polymerization-induced self-assembly in the presence of iron-oxide nanoparticles. Detailed phase diagrams with and without inorganic nanoparticles were constructed. Scanning transmission electron microscopy and energy dispersive X-ray photometry studies confirme the decoration of the polymeric nanoparticles with the iron-oxide nanoparticles. These hybrid nanoparticles were used to prepare porous thin film membranes by spin coating. Finally, the magneto-responsive properties of the membranes were assessed using water filtration tests in the presence and absence of a magnetic field.


Assuntos
Técnicas de Química Sintética/métodos , Nanopartículas de Magnetita/química , Nanopartículas/química , Polímeros/química , Ácidos Polimetacrílicos/química , Polimetil Metacrilato/química , Materiais Revestidos Biocompatíveis/química , Campos Magnéticos , Nanopartículas de Magnetita/ultraestrutura , Membranas Artificiais , Microscopia Eletrônica de Transmissão e Varredura , Nanopartículas/ultraestrutura , Polimerização , Polímeros/síntese química , Porosidade
10.
Carbohydr Polym ; 191: 216-224, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29661312

RESUMO

The purpose of this work is the development and characterisation of new hybrid polysaccharide (FucoPol) membranes. These membranes were prepared by incorporation of a SiO2 network homogeneously dispersed by using a sol-gel method with GPTMS as a crosslinker silica precursor. They were further crosslinked with CaCl2 for reinforcement of mechanical properties and improvement of their permeation performance. They were characterised in terms of their structural, mechanical and thermal properties. They presented a dense and homogeneous structure, resistant to deformation, with a Tg of 43 °C and a thermal decomposition between 240 and 251 °C. The hybrid FucoPol membranes were tested for ethanol dehydration by pervaporation and also for nitrogen dehydration. They exhibited high water selectivity values, similar to PERVAP® 4101, however they lost their stability when exposed to solutions of 10.0 wt.% water in ethanol. In contrast, these membranes were stable when applied in N2 dehydration, leading to reproducible performance and very high water selectivities.

11.
Membranes (Basel) ; 7(1)2017 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-28264453

RESUMO

Extremely high removals of total suspended solids and oil and grease were obtained when olive mill wastewaters were filtered using new silicon carbide tubular membranes. These new membranes were used at constant permeate flux to treat real olive mill wastewaters at pilot scale. The filtration conditions were evaluated and optimized in terms of the selection of the permeate flux and flux maintenance strategies employed-backpulsing and backwashing-in order to reduce fouling formation. The results obtained reveal that the combination of backpulses and backwashes helps to maintain the permeate flux, avoids transmembrane pressure increase and decreases the cake resistance. Moreover, membrane cleaning procedures were compared and the main agents responsible for fouling formation identified. Results also show that, under total recirculation, despite an increased concentration of pollutants in the feed stream, the quality of the permeate is maintained. Membrane filtration using silicon carbide membranes is an effective alternative to dissolved air flotation and can be applied efficiently to remove total suspended solids and oil and grease from olive mill wastewaters.

12.
J Environ Manage ; 181: 762-769, 2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-27444721

RESUMO

Experiments for treating two different types of hazardous oil refinery effluents were performed in order to avoid/minimize their adverse impacts on the environment. First, refinery wastewater was subjected to ultrafiltration using a ceramic membrane, treatment, which did not provide an adequate reduction of the polar oil and grease content below the maximal contaminant level allowed. Therefore the option of reducing the polar oil and grease contamination at its main emission source point in the refinery - the spent caustic originating from the refinery kerosene caustic washing unit - using an alkaline-resistant nanofiltration polymeric membrane treatment was tested. It was found that at a constant operating pressure and temperature, 99.9% of the oil and grease and 97.7% of the COD content were rejected at this emission point. Moreover, no noticeable membrane fouling or permeate flux decrease were registered until a spent caustic volume concentration factor of 3. These results allow for a reuse of the purified permeate in the refinery operations, instead of a fresh caustic solution, which besides the improved safety and environmentally related benefits, can result in significant savings of 1.5 M€ per year at the current prices for the biggest Portuguese oil refinery. The capital investment needed for nanofiltration treatment of the spent caustic is estimated to be less than 10% of that associated with the conventional wet air oxidation treatment of the spent caustic that is greater than 9 M€. The payback period was estimated to be 1.1 years. The operating costs for the two treatment options are similar, but the reuse of the nanofiltration spent caustic concentrate for refinery pH control applications can further reduce the operating expenditures. Overall, the pilot plant results obtained and the process economics evaluation data indicate a safer, environmentally friendly and highly competitive solution offered by the proposed nanofiltration treatment, thus representing a promising alternative to the use of conventional spent caustic treatment units.


Assuntos
Conservação dos Recursos Naturais/métodos , Resíduos Industriais , Membranas Artificiais , Indústria de Petróleo e Gás , Ultrafiltração/métodos , Eliminação de Resíduos Líquidos/métodos , Resíduos Industriais/análise , Projetos Piloto , Polímeros , Águas Residuárias/análise
13.
Environ Sci Pollut Res Int ; 23(11): 11279-11288, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26924700

RESUMO

A sequential water treatment combining low pressure ultraviolet direct photolysis with nanofiltration was evaluated to remove hormones from water, reduce endocrine disrupting activity, and overcome the drawbacks associated with the individual processes (production of a nanofiltration-concentrated retentate and formation of toxic by-products). 17ß-Estradiol, 17α-ethinylestradiol, estrone, estriol, and progesterone were spiked into a real water sample collected after the sedimentation process of a drinking water treatment plant. Even though the nanofiltration process alone showed similar results to the combined treatment in terms of the water quality produced, the combined treatment offered advantage in terms of the load of the retentate and decrease in the endocrine-disrupting activity of the samples. Moreover, the photolysis by-products produced, with higher endocrine disrupting activity than the parent compounds, were effectively retained by the membrane. The combination of direct LP/UV photolysis with nanofiltration is promising for a drinking water utility that needs to cope with sudden punctual discharges or deterioration of the water quality and wants to decrease the levels of chemicals in the nanofiltration retentate.


Assuntos
Água Potável/análise , Disruptores Endócrinos/análise , Filtração , Hormônios/análise , Raios Ultravioleta , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Água Potável/normas , Disruptores Endócrinos/efeitos da radiação , Hormônios/efeitos da radiação , Fotólise , Poluentes Químicos da Água/efeitos da radiação , Qualidade da Água
14.
Water Res ; 88: 184-198, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26497936

RESUMO

Reverse electrodialysis (RED) is one of the emerging, membrane-based technologies for harvesting salinity gradient energy. In RED process, fouling is an undesirable operation constraint since it leads to a decrease of the obtainable net power density due to increasing stack electric resistance and pressure drop. Therefore, early fouling detection is one of the main challenges for successful RED technology implementation. In the present study, two-dimensional (2D) fluorescence spectroscopy was used, for the first time, as a tool for fouling monitoring in RED. Fluorescence excitation-emission matrices (EEMs) of ion-exchange membrane surfaces and of natural aqueous streams were acquired during one month of a RED stack operation. Fouling evolvement on the ion-exchange membrane surfaces was successfully followed by 2D fluorescence spectroscopy and quantified using principal components analysis (PCA). Additionally, the efficiency of cleaning strategy was assessed by measuring the membrane fluorescence emission intensity before and after cleaning. The anion-exchange membrane (AEM) surface in contact with river water showed to be significantly affected due to fouling by humic compounds, which were found to cross through the membrane from the lower salinity (river water) to higher salinity (sea water) stream. The results obtained show that the combined approach of using 2D fluorescence spectroscopy and PCA has a high potential for studying fouling development and membrane cleaning efficiency in ion exchange membrane processes.


Assuntos
Técnicas Eletroquímicas , Substâncias Húmicas , Troca Iônica , Membranas Artificiais , Salinidade , Espectrometria de Fluorescência/métodos , Água Doce/química , Análise de Componente Principal , Água do Mar/química
15.
J Phys Chem B ; 119(35): 11740-7, 2015 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-26252801

RESUMO

A proton nuclear magnetic relaxation dispersion (1)H NMRD study of the molecular dynamics in mixtures of magnetic ionic liquid [P66614][FeCl4] with [P66614][Cl] ionic liquid and mixtures of [P66614][FeCl4] with dimethyl sulfoxide (DMSO) is presented. The proton spin-lattice relaxation rate, R1, was measured in the frequency range of 8 kHz-300 MHz. The viscosity of the binary mixtures was measured as a function of an applied magnetic field, B, in the range of 0-2 T. In the case of DMSO/[P66614][FeCl4] the viscosity was found to be independent from the magnetic field, while in the case of the [P66614][Cl]/[P66614][FeCl4] system viscosity decreased with the increase of the magnetic field strength. The spin-lattice relaxation results were analyzed for all systems taking into account the relaxation mechanisms associated with the molecular motions with correlation times in a range between 10(-11) and 10(-7)s, usually observed by NMRD, and the paramagnetic relaxation contributions associated with the presence of the magnetic ions in the systems. In the case of the DMSO/[P66614][FeCl4] system the R1 dispersion shows the relaxation enhancement due to the presence of the magnetic ions, similar to that reported for contrast agents. For the [P66614][Cl]/[P66614][FeCl4] system, the R1 dispersion presents a much larger paramagnetic relaxation contribution, in comparison with that observed for the DMSO/[P66614][FeCl4] mixtures but different from that reported for other magnetic ionic liquid system. In the [P66614][Cl]/[P66614][FeCl4] system the relaxation enhancement associated with the paramagnetic ions is clearly not proportional to the concentration of magnetic ions, in contrast with what is observed for the DMSO/[P66614][FeCl4] system.

16.
J Biotechnol ; 189: 166-74, 2014 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-25242664

RESUMO

The impact of surface topography on the structure of proteins upon adhesion was assessed through non-invasive fluorescence monitoring. This study aimed at obtaining a better understanding about the role of protein structural status on cell-scaffold interactions. The changes induced upon adsorption of two model proteins with different geometries, trypsin (globular conformation) and fibrinogen (rod-shaped conformation) on poly-l-lactic acid (PLLA) scaffolds with different surface topographies, flat, fibrous and surfaces with aligned nanogrooves, were assessed by fluorescence spectroscopy monitoring, using tryptophan as structural probe. Hence, the maximum emission blue shift and the increase of fluorescence anisotropy observed after adsorption of globular and rod-like shaped proteins on surfaces with parallel nanogrooves were ascribed to more intense protein-surface interactions. Furthermore, the decrease of fluorescence anisotropy observed upon adsorption of proteins to scaffolds with fibrous morphology was more significant for rod-shaped proteins. This effect was associated to the ability of these proteins to adjust to curved surfaces. The additional unfolding of proteins induced upon adsorption on scaffolds with a fibrous morphology may be the reason for better cell attachment there, promoting an easier access of cell receptors to initially hidden protein regions (e.g. RGDS sequence), which are known to have a determinant role in cell attaching processes.


Assuntos
Proteínas/química , Espectrometria de Fluorescência/métodos , Tecidos Suporte/química , Materiais Biocompatíveis/química , Ácido Láctico/química , Poliésteres , Polímeros/química
17.
J Colloid Interface Sci ; 428: 16-23, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-24910029

RESUMO

HYPOTHESIS: Magnetic Ionic Liquid (MILs), novel magnetic molecules that form "pure magnetic liquids," will follow the Ferrohydrodynamic Bernoulli Relationship. Based on recent literature, the modeling of this fluid system is an open issue and potentially controversial. EXPERIMENTS: We imposed uniform magnetic fields parallel to MIL/air interfaces where the capillary forces were negligible, the Quincke Problem. The size and location of the bulk fluid as well as the size and location of the fluid/air interface inside of the magnetic field were varied. MIL properties varied included the density, magnetic susceptibility, chemical structure, and magnetic element. FINDINGS: Uniform tangential magnetic fields pulled the MILs up counter to gravity. The forces per area were not a function of the volume, the surface area inside of the magnetic field, or the volume displacement. However, the presence of fluid/air interfaces was necessary for the phenomena. The Ferrohydrodynamic Bernoulli Relationship predicted the phenomena with the forces being directly related to the fluid's volumetric magnetic susceptibility and the square of the magnetic field strength. [emim][FeCl4] generated the greatest hydraulic head (64-mm or 910 Pa at 1.627 Tesla). This work could aid in experimental design, when free surfaces are involved, and in the development of MIL applications.

18.
J Food Sci ; 79(6): E1142-9, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24891032

RESUMO

UNLABELLED: Natural extracts obtained from grape pomace are particularly interesting, due to the substantial variety of valuable compounds present with health benefits, specifically phenolic compounds such as anthocyanins, trans-resveratrol, quercetin, and proanthocyanidins. The production of such extracts has been recognized as a profitable way to valorize grape byproducts, which are low-value and most abundant. First, the effect of the solvent on the extraction of bioactive compounds from grape pomace is studied. The selected solvents are water and ethanol, biocompatible and available in wineries and distilleries. Then, different types of grape pomace obtained along the various stages of current industrial winemaking and distillation processes are analyzed. As a result, the best stage of the winemaking and distillation processes for pomace valorization is identified, corresponding to the grape byproduct with the highest potential as source of bioactive compounds. These studies were performed with Vitis vinifera variety of Tempranillo grapes (same year, same vineyard). PRACTICAL APPLICATION: This work optimizes the production of natural extracts from (byproduct) grape pomace with recognized health benefits, to be used as high value nutraceuticals ingredients. The process proposed uses renewable and low-cost resources existent in wineries and distilleries. The select solvent extracting is a mixture of the biocompatible water and ethanol. The selected fermented grape pomace was chosen from different and comparable types of grape pomace obtained at current winemaking and distillation processes, to be used in extraction without any pretreatment.


Assuntos
Flavonoides/análise , Frutas/química , Fenóis/análise , Vitis/química , Vinho/análise , Dieta , Humanos , Solventes
19.
J Hazard Mater ; 264: 65-70, 2014 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-24275472

RESUMO

Mercury is a highly toxic heavy metal that causes human health problems and environmental contamination. In this study, an ion exchange membrane bioreactor (IEMB) process was developed to achieve Hg(II) removal from drinking water and industrial effluents. Hg(II) transport through a cation exchange membrane was coupled with its bioreduction to Hg(0) in order to achieve Hg removal from concentrated streams, with minimal production of contaminated by-products observed. This study involves (1) membrane selection, (2) demonstration of process effectiveness for removing Hg from drinking water to below the 1ppb recommended limit, and (3) process application for treatment of concentrated water streams, where >98% of the Hg was removed, and the throughput of contaminated water was optimised through membrane pre-treatment. The IEMB process represents a novel mercury treatment technology with minimal generation of contaminated waste, thereby reducing the overall environmental impact of the process.


Assuntos
Mercúrio/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/instrumentação , Reatores Biológicos , Substâncias Perigosas/isolamento & purificação , Troca Iônica , Membranas Artificiais , Águas Residuárias/química
20.
J Environ Manage ; 131: 161-9, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24161805

RESUMO

In this study, a nanofiltration unit was implemented at an industrial site, for the treatment of industrial wastewater generated during rubber tubing extrusion. The aim was to reduce the energy input required, while assuring a final effluent quality that meets the requirements of environmental legislation. In a first stage, two membrane process treatments, ultrafiltration and nanofiltration, were evaluated at laboratory scale in order to assess the rejection of pollutants and maximise permeate throughput. Permeate generated from nanofiltration using either an NF90 or an NF270 membrane were shown to meet the effluent discharge requirements (<2000 mg COD/l). The less restrictive membrane, NF270, was chosen for study in a pilot plant at the industrial site, due to its higher membrane permeability. The pilot nanofiltration unit was integrated into the treatment plant operation aiming at optimising the process in terms of the efficiency of pollutant removal with minimal energy input. A feasibility study was performed for this case-study and it was concluded that the energy expenditure of the new process represents only 62% of the current energy consumption of the treatment plant. The proposed solution in this work may be retrofitted to full scale wastewater treatment processes, and may be applicable to industries that employ similar manufacturing processes, and face similar difficulties.


Assuntos
Ultrafiltração/instrumentação , Eliminação de Resíduos Líquidos/instrumentação , Membranas , Projetos Piloto
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