Valorization of keratin biofibers for removing heavy metals from aqueous solutions

Four common waste keratin biofibers (human hair, dog hair, chicken feathers, and degreased wool) have been used as biosorbents for the removal of heavy metal ions from aqueous solutions. Different parameters of the biosorption processes were optimized in batch systems. For multiple-metal systems, consisting of a mixture of eight metal ions [Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(II)], the total metal biosorption increased in the order: degreased wool¿>¿chicken feathers¿>¿human hair¿>¿dog hair. From the kinetic models tested, the pseudo-second-order model provided better results. Furthermore, biosorption isotherms of Pb(II) with the different keratin biofibers fitted the Langmuir model. Surface morphology of the biosorbents were analyzed before and after the sorption using Fourier transform infrared spectroscopy and scanning electron microscopy. The keratin biofibers tested are potentially good sorbents of metal ions, with degreased wool and chicken feathers being the more efficient onesPostprint (author's final draft

La Societat Econòmica Barcelonesa d’Amics del País durant la primera meitat del segle XIX: origen, organització i principals línies d’actuació

Aquest article s’ocupa inicialment de l’origen de les societats econòmiques en el segle XVIII i, tot seguit, traça els trets fundacionals i organitzatius del vessant barceloní d’aquestes corporacions, així com de les seves principals línies d’actuació, al llarg de la primera meitat del segle XIX. Sota el nom de Societat Econòmica Barcelonesa d’Amics del País, aquesta entitat va assumir un protagonisme destacat dins del panorama associatiu barceloní d’aquells anys i va portar a terme una intensa tasca en diversos camps. Tot això gràcies a la presència, entre les seves files, d’una nodrida representació del bo i millor de la burgesia de la ciutat comtal.This article initially talks about the origins of economic societies in the XVIIIth century, then points at the foundation and organizational characteristics of these types of corporations from Barcelona, along with their main areas of interest throughout the first half of the XIXth century. Under the name of Societat Econòmica Barcelonesa d’Amics del País (Economic Society of Barcelona and Friends of the Country), this society was notably prominent within the panorama of associations of Barcelona during that time and did an immense amount of work in different fields. This was in no small part due to the presence, among its members, of a large representation of the finest members of the bourgeoise of Barcelona