5 research outputs found
Valorization of artichoke wastewaters by integrated membrane process
In this work an integrated membrane system was developed on laboratory scale to fractionate artichoke wastewaters. In particular, a preliminary ultrafiltration (UF) step, based on the use of hollow fibre membranes, was investigated to remove suspended solids from an artichoke extract. The clarified solution was then submitted to a nanofiltration (NF) step. Two different 2.5 × 21 in. spiral-wound membranes (Desal DL and NP030) with different properties were investigated. Both membranes showed a high rejection towards the phenolic compounds analysed (chlorogenic acid, cynarin and apigenin-7-O-glucoside) and, consequently, towards the total antioxidant activity (TAA). On the other hand, the Desal DL membrane was characterized by a high rejection towards sugar compounds (glucose, fructose and sucrose) (100%) when compared with the NP030 membrane (4.02%).
The performance of selected membranes in terms of permeate flux, fouling index and water permeability recovery was also evaluated.
On the base of experimental results, an integrated membrane process for the fractionation of artichoke wastewaters was proposed. This conceptual process design permitted to obtain different valuable products: a retentate fraction (from the NP030 membrane) enriched in phenolic compounds suitable for nutraceutical, cosmeceutical or food application; a retentate fraction (from the Desal DL membrane), enriched in sugar compounds, of interest for food applications; a clear permeate (from the Desal DL membrane) which can be reused as process water or for membrane cleaning.Conidi, C.; Cassano, A.; García Castelló, EM. (2014). Valorization of artichoke wastewaters by integrated membrane process. Water Research. 48:363-374. doi:10.1016/j.watres.2013.09.047S3633744
Purification of artichoke polyphenols by using membrane filtration and polymeric resins
The present study aimed at evaluating the potential of an integrated process based on the use of membrane technology and adsorbent resins for the recovery, concentration and purification of phenolic compounds from artichoke wastewaters.
In particular, artichoke wastewaters coming from the blanching step were pre-treated by ultrafiltration (UF) in order to remove suspended solids and macromolecular compounds. The UF permeate was submitted to a nanofiltration (NF) process producing a concentrated fraction enriched in phenolic and sugar compounds.
Three different macroporous resins were tested through adsorption/desorption methods to produce purified phenolic fractions with high antioxidant activity. Samples produced in UF, NF and adsorption desorption tests were assayed for phenolic composition (chlorogenic acid and apigenin 7-O-glucoside), sugar composition (fructose, glucose and sucrose) and antioxidant activity.
Among the three different tested resins, the S 7968 offered the best performance in terms of adsorption/desorption ratio for chlorogenic acid, with a total adsorption/desorption yield (TADY) of 63.39%; for the apigenin 7-O-glucoside the S 7968 and the S 2328 resins showed a TADY in the range 68.31-78.45%. (c) 2015 Elsevier B.V. All rights reserved.Authors acknowledge the Vicerrectorado de Investigacion of the "Universitat Politecnica de Valencia" for the financial support (project 1965) from the call "Proyectos de Nuevas Lineas de Investigacion Mul-tidisciplinares (PAID05-11)".Conidi, C.; Rodríguez López, AD.; Garcia-Castello, EM.; Cassano, A. (2015). Purification of artichoke polyphenols by using membrane filtration and polymeric resins. Separation and Purification Technology. 144(1):153-161. https://doi.org/10.1016/j.seppur.2015.02.025S153161144
La lutte des « Sans-papières »
Durant les années 1970-1980, l'immigration se déclinait au masculin. Les luttes dans lesquelles les femmes africaines ont joué un rôle important, de manière répétée, leur apparition sur la scène publique, leur regroupement dans de multiples associations figurent en bonne place parmi les facteurs qui ont contribué à la visibilité des femmes en migration. Voici plus de quatre ans que certaines d'entre elles, de nationalités différentes, se sont engagées dans la lutte des sans-papiers. Madjiguen..