Search results for "Microfiltration"
showing 10 items of 13 documents
Experimental study of the anaerobic urban wastewater treatment in a submerged hollow-fibre membrane bioreactor at pilot scale
2011
The aim of this study was to assess the effect of several operational variables on both biological and separation process performance in a submerged anaerobic membrane bioreactor pilot plant that treats urban wastewater. The pilot plant is equipped with two industrial hollow-fibre ultrafiltration membrane modules (PURON¿ Koch Membrane Systems, 30m 2 of filtration surface each). It was operated under mesophilic conditions (at 33°C), 70days of SRT, and variable HRT ranging from 20 to 6h. The effects of the influent COD/SO 4-S ratio (ranging from 2 to 12) and the MLTS concentration (ranging from 6 to 22gL -1) were also analysed. The main performance results were about 87% of COD removal, efflu…
Heterogeneous photocatalytic degradation of pharmaceuticals in water by using polycrystalline TiO2 and a nanofiltration membrane reactor
2006
Abstract A study of the photodegradation of different pharmaceuticals [furosemide, ranitidine (hydrochloride), ofloxacine, phenazone, naproxen, carbamazepine and clofibric acid] in aqueous medium at various pHs by using a batch photoreactor and a photocatalytic membrane reactor working in recirculation regime was carried out. Polycrystalline TiO 2 was used as the photocatalyst, and different membranes (NTR 7410, PAN GKSS HV3/T, N 30 F, NF PES 10) were tested. A different adsorption of the substrates onto the catalyst surface was observed owing to the hydrophilic/hydrophobic character of the catalyst, depending on the pH. The photodegradation of the seven molecules in the batch reactor was s…
Operational and financial effectiveness of e-collaboration tools in supply chain integration
2004
This paper develops a comprehensive model of supply chain integration and uses it to analyze and assess the operational and financial effectiveness of different e-collaboration tools at various levels of supply chain integration. This model is also used to evaluate the importance of the sequence in which e-collaboration tools are adopted in supply chain integration. Computational results from a validated system dynamics simulation model with different implementation sequences of e-collaboration tools and different financial scenarios show that local financial constraints can also severely impact operational and financial performance of the entire supply chain. (C) 2003 Elsevier B.V. All rig…
Preparation, Characterisation and Testing of Photocatalytic Polymeric Membranes with Entrapped or Suspended TiO2
2005
Various cellulose triacetate (CTA) or polysulfone (PSf) membranes with entrapped polycrystalline TiO2 were prepared by using different methods of the so-called phase inversion process. Porosity and permeability of the membranes increased by increasing the amount of entrapped TiO2 while rejection decreased. The photoactivity of entrapped TiO2 for the degradation of congo-red was compared with that of the same quantity of suspended TiO2 and the results indicated that TiO2 was always more efficient when used in suspension. A hybrid configuration consisting of a continuous membrane photoreactor with the photocatalyst in suspension showed to be the most promising one.
Advancements in Sustainable PVDF Copolymer Membrane Preparation Using Rhodiasolv® PolarClean As an Alternative Eco-Friendly Solvent
2021
In this work, Rhodiasolv® PolarClean was employed as a more sustainable solvent for the preparation of poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) flat sheet membranes via phase inversion technique by coupling vapour induced phase separation (VIPS) and non-solvent induced phase separation (NIPS) processes. Preliminary calculations based on Hansen solubility parameters well predicted the solubilization of the polymer in the selected solvent. The effect of exposure time on humidity and the influence of polyethylene glycol (PEG), polyvinyl pyrrolidone (PVP) and sulfonated polyether sulfone (S-PES) on membrane properties and performance, were evaluated. Three different coagulation …
Electrospun nanofibers: role of nanofibers in water remediation and effect of experimental variables on their nano topography and application process…
2021
Water is the elixir of life and the most elementary need for the survival of human beings on planet Earth. With rapid industrialization, globalization and human exploitation, natural water resources are diminishing at a startling rate wherein availability of potable water has drastically decreased in recent times and hence membrane technology is a highly pursued area for water purification. The simple and cost-effective electrospinning technique has evolved to be a state-of-the-art method for developing nanofibers of tailored thickness and diameters by combining a broad range of starting materials. This comprehensive review emphasizes on the demonstration of electrospun nanofibers based on …
The combination of heterogeneous photocatalysis with chemical and physical operations: a tool for improving the photoprocess performance
2006
Heterogeneous photocatalysis is a process of great potential for pollutant abatement and waste treatment. In order to improve the overall performance of the photoprocess, heterogeneous photocatalysis is being combined with physical or chemical operations, which affect the chemical kinetics and/or the overall efficiency. This review addresses the various possibilities to couple heterogeneous photocatalysis with other technologies to photodegrade organic and inorganic pollutants dissolved in actual or synthetic aqueous effluents. These combinations increase the photoprocess efficiency by decreasing the reaction time in respect to the separated operations or they decrease the cost in respect o…
Impact of a minimally processing route for the production of infant formulas on the organoleptic properties
2022
Many new-borns are fed with substitutes of breast milk. These products undergo several heat treatments, necessary to insure their microbiologic safety but probably modifying their organo-leptic properties. High temperature can damage milk proteins and form Maillard reaction prod-ucts with lactose. Microfiltration – to replace the heat treatments for a milk debacterization – combined with a soft spray-drying is currently an alternative little exploited to produce infant formulas (IFs) although microbiologically safe. The aim of this study was to determine the im-pact of such processing route on the organoleptic properties of the IFs. Three experimental IFs were manufactured at a semi-industr…
Sub-critical filtration conditions of commercial hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system: The effect of gas sparging i…
2012
A submerged anaerobic MBR demonstration plant with two commercial hollow-fibre ultrafiltration systems (PURON®, Koch Membrane Systems, PUR-PSH31) was operated using municipal wastewater at high levels of mixed liquor total solids (MLTS) (above 22gL -1). A modified flux-step method was applied to assess the critical flux (J C) at different gas sparging intensities. The results showed a linear dependency between J C and the specific gas demand per unit of membrane area (SGD m). J C ranged from 12 to 19LMH at SGD m values of between 0.17 and 0.5Nm 3h -1m -2, which are quite low in comparison to aerobic MBR. Long-term trials showed that the membranes operated steadily at fluxes close to the est…
Studies and Researches on the Obtaining of Sintered Gradual Porous Structures by Irregular Nickel Powders Sedimentation
2012
The aim of this work is to obtain sintered porous membranes with graded structure for microfiltration by sedimentation and sintering of metallic powders. Our previous studies have demonstrated the possibility of obtaining sintered porous materials with graded structure by sedimentation. In this paper, irregular nickel particles were used having a grain size in the 2-90 µm range evaluated using scanning electron microscopy and laser scattering particle size analyzer. The powders were sedimented into a sintering die in a sedimentation medium consisting of water and dispersant agent. After drying, the samples were sintered at 1000°C for 10 minutes in vacuum (~1•10-3 Pa). The structures obtaine…