Salt cleaning of ultrafiltration membranes fouled by whey model solutions

In this work, three ultrafiltration (UF) membranes were fouled with whey model solutions that contained BSA (1% w/w) and CaCl2 (0.06% w/w). These membranes were cleaned with NaCl solutions. Temperature, crossflow velocity and concentration were varied. The membranes considered were a polyethersulfone (PES) membrane, a ceramic ZrO2–TiO2 membrane and a permanently hydrophilic polyethersulfone (PESH) membrane. Their molecular weight cut-offs (MWCOs) are 5, 15 and 30 kDa, respectively. The cleaning efficiency was related to the MWCO, membrane material and operating conditions. The results obtained demonstrated that NaCl solutions were able to clean the membranes tested. In addition, the higher the temperature and the crossflow velocity of the cleaning solution, the higher the cleaning efficiency was. However, there was an optimum value of NaCl concentration to clean the membranes effectively. When concentration was higher than the optimum, the cleaning efficiency decreased. The relationship between the cleaning efficiency and the operating conditions was obtained with statistical and optimization analysis.The authors of this work wish to gratefully acknowledge the financial support from the Spanish Ministry of Science and Innovation through the project CTM2010-20186 and the Generalitat Valenciana through the program "Ayudas para la realizacion de proyectos I+D para grupos de investigacion emergentes GV/2013".Corbatón Báguena, MJ.; Alvarez Blanco, S.; Vincent Vela, MC. (2014). Salt cleaning of ultrafiltration membranes fouled by whey model solutions. Separation and Purification Technology. 132:226-233. https://doi.org/10.1016/j.seppur.2014.05.029S22623313

Cleaning of ultrafiltration membranes fouled with BSA by means of saline solutions

In this work, four ultrafiltration (UF) membranes with molecular weight cut-offs (MWCOs) of 5, 15, 30 and 50 kDa, respectively, were fouled with 1% BSA aqueous solutions and cleaned with different saline solutions. The influence of MWCO, membrane material and operating conditions on the cleaning effi- ciency was investigated. Saline solutions were able to clean the 5, 15 and 30 kDa membranes, but not the 50 kDa membrane. NaCl, NaNO3, NH4Cl and KCl were the most effective salts. The cleaning tests demonstrated that the higher the temperature of the saline solution was, the higher the cleaning efficiency was also. In addition, an increase in the crossflow velocity resulted in an increase in the hydraulic cleaning efficiency (HCE). However, there was an optimum value of salt concentration to clean the membrane effectively. Response Surface Methodology was used to investigate the relationship between salt concentration and temperature in the cleaning process.The authors of this work wish to gratefully acknowledge the financial support from the Spanish Ministry of Science and Innovation through the project CTM2010-20186 and the Generalitat Valenciana through the program "Ayudas para la realizacion de proyectos I+D para grupos de investigacion emergentes GV/2013".Corbatón Báguena, MJ.; Alvarez Blanco, S.; Vincent Vela, MC. (2014). Cleaning of ultrafiltration membranes fouled with BSA by means of saline solutions. Separation and Purification Technology. 125(7):1-10. https://doi.org/10.1016/j.seppur.2014.01.035S110125

Ultrafiltration of whey: membrane performance and modelling using a combined pore blocking-cake formation model

[EN] BACKGROUNDUltrafiltration has been considered as a green' technique to treat different industrial wastewaters, such as whey in the dairy industry. However, fouling is one of the major drawbacks in the industrial implementation of this process. Thus, in this work, the performance of ultrafiltration membranes was investigated in terms of permeate flux and protein rejection when treating different whey model solutions. Modelling of permeate flux was performed combining two main fouling mechanisms (complete pore blocking and cake formation) by a time-dependent pore blocking parameter. RESULTSResults demonstrated that high protein concentration and the presence of calcium salts in the feed solution favoured permeate flux decline. The combined model was appropriate to describe the main fouling mechanisms, with fitting accuracies higher than 0.960. Model parameters were correlated with both calcium and protein concentration and the developed model was successfully validated with an additional fouling test. CONCLUSIONAll the membranes tested were suitable for carrying out whey protein separation, with rejection indexes greater than 99%. The combined model and the statistical correlation of model parameters with calcium and protein concentrations were useful to predict permeate flux decline when the ultrafiltration of a new whey model solution was performed. (c) 2017 Society of Chemical IndustryThis work was supported by the Spanish Ministry of Science and Innovation (project CTM2010-20186).Corbatón Báguena, MJ.; Alvarez Blanco, S.; Vincent Vela, MC. (2018). Ultrafiltration of whey: membrane performance and modelling using a combined pore blocking-cake formation model. Journal of Chemical Technology & Biotechnology. 93(7):1891-1900. https://doi.org/10.1002/jctb.5446]S1891190093

Fighting for a (wide enough) seat at the table: weight stigma in law and policy

Few jurisdictions provide legal protection against discrimination on the basis of weight despite evidence of pervasive inequalities faced by fat individuals in employment, healthcare, education, and other domains. Yet, in the last two decades, advocacy efforts in several countries aimed to remedy this situation have been largely unsuccessful. We present a cross-national conceptual analysis of three significant anti-discrimination developments regarding weight in the United Kingdom, the United States, and Iceland, respectively, to highlight how the creation, implementation, and enforcement of legal and policy mechanisms that prohibit weight discrimination ironically suffer under the very burden of deeply rooted structural stigmas against fatness and fat bodies that such efforts seek to counter. However, drawing on research around policy change in response to other social movements, we conclude that we may be at a time where broad-ranging policy change could become a reality

Etude critique d'une installation industrielle de microfiltration et ultrafiltration tangentielles pour la production de concentres de proteines de lactoserum de haute purete

National audienc