Search results for "SEPARATION"

Removal of toxic pollutants from pulp mill effluents by electrocoagulation

2011

This study investigated the effect of electrocoagulation treatment on toxic pollutant removal from pulp mill effluents. Synthetic wastewaters containing wood rosin and copper or pure resin acids were used to investigate the removal of resin acids and copper by electrocoagulation. Removal of pollutants by electrocoagulation was also tested with real debarking effluent. In this study, statistical experimental design and partial least squares modeling were used to investigate the effect of initial pH, current (current density) and treatment time. Electrocoagulation and subsequent filtration removed resin acids and copper from the synthetic wastewaters with high efficiency. Toxicity to algae (P…

Composites poly-lactic acid - hydroxyapatite scaffolds prepared via Thermally Induced Phase Separation

2013

USO DI TECNICHE AVANZATE PER LA OTTIMIZZAZIONE STRUTTURALE E FUNZIONALE DI SCAFFOLD COMPOSITI POLIMERO-CARICA INORGANICA PER LA RIGENERAZIONE OSSEA.

2020

AN EXPERIMENTAL APPARATUS TO CHARACTERIZE PHASE SEPARATION IN POLYMER SOLUTIONS

2013

Measurement of cloud point temperature in polymer solutions

2013

Simultaneous application of vacuum and sweep gas in a polypropylene membrane contactor for the recovery of dissolved methane from water

2021

Abstract Vacuum and nitrogen as sweep gas were used simultaneously (combination mode) to generate the driving force in a microporous polypropylene membrane contactor for the recovery of dissolved methane from water. Experiments were carried out under different liquid flow-rates (5.0–28.0 L h−1), N2 flow-rates (0.5–1.5 L h−1) and vacuum pressures (0–480 mbar). The maximum removal efficiency of methane was >90% at moderate values of gas-to-liquid ratios (G/L) and vacuum of 0.2 and ≤ 200 mbar, respectively. Removal efficiencies obtained in combination mode were usually higher than when using vacuum or sweep gas, separately. To achieve a methane content >35% in the recovered gas, G/L values low…

Recovery of dissolved methane through a flat sheet module with PDMS, PP, and PVDF membranes

2022

Abstract A degassing contactor using a flat sheet membrane module (FM) was operated in sweep gas mode to study the performance of several commercial polymer membranes, both dense (polydimethylsiloxane, PDMS) and microporous (polypropylene, PP, and polyvinylidenefluoride, PVDF), for the recovery of dissolved methane from water. Non-steady state experiments were conducted at different liquid (QL, 3.5–40.5 L h-1) and gas flow rates (QN2, 0.05–15.00 L h-1). In the case of PDMS, PP, and when PVDF was operated at moderate high QL (≥ 21 L h-1), similar methane removal efficiencies (RE) were obtained. In the case of PVDF operated at relatively low QL (3.5 L h-1), a lower RE was observed. A model fo…

Investigations of polymerizable multilayers as gas separation membranes

1985

Abstract Polymerizable Langmuir—Blodgett (LB) multilayers of several diacetylenic amphiphiles were investigated on gas-permeable, polymeric supports. Macroscopically homogeneous multilayer films of hexacosa-10,12-diynoic acid and pentacosa-10,12-diyne phosphonate could be built up on polypropylene and polytetrafluoroethylene materials. As shown by scanning electron microscopy, the microscopic homogeneity of the built-up multilayers was mainly controlled by the surface structure of the support material, whereas the chemical nature of the support and photopolymerization of the layers did not affect the high order of the films. Such LB multilayers deposited on porous support materials are able…

Vivir como cristianos y pagar como moros: genealogía medieval de la servidumbre morisca en el reino de Valencia

2009

La conversión forzosa de los musulmanes del reino de Valencia, decretada en 1526, no implicó una igualación social entre cristianos «viejos» y «nuevos», ya que se mantuvo la diferencia de estatus que había existido anteriormente. El artículo examina los tres aspectos fundamentales del contenido de dicha diferencia: la intensidad de las rentas soportadas, la imposición de servicios obligatorios y las trabas a la migración interior y exterior; establece sus orígenes en las condiciones de dominación impuestas a la población infiel inmediatamente después de la conquista del siglo XIII, y traza los grandes rasgos de su evolución a lo largo de la Baja Edad Media. Se arguye que esta población estu…

Evidence of Mechanisms Occurring in Thermally Induced Phase Separation of Polymeric Systems

2014

Thermally induced phase separation is a fabrication technique for porous polymeric structures. By means of easy-to-tune processing parameters, such as system composition and demixing temperature, a vast latitude of average pore dimensions, pore size distributions, and morphologies can be obtained. The relation between demixing temperature and morphology was demonstrated via cloud point curve measurement and foams fabrication with controlled thermal protocols, for the model system poly-l-lactide–dioxane–water. The morphologies obtained at a temperature lower than cloud point showed a closed-pore architecture, suggesting a “nucleation-and-growth” separation mechanism, which produced larger po…