Faujasite zeolite decorated with cobalt ferrite nanoparticles for improving removal and reuse in Pb^2+ions adsorption

Water pollution caused by heavy metals ions has been gaining attention in recent years,increasing the interest in the development of methodologies for their efficient removal focusing on the adsorption process for these purposes.The current challenge faced by adsorption processes is the adequate adsorbent immobilization for removal and reuse.Thus,the present work aimed at producing a faujasite zeolite nanocomposite decorated with cobalt ferrite nanoparticles for Pb^2+ions adsorption in an aqueous medium improving magnetic removal and reuse.As a result,a high surface area(434.4 m^2·g^-1)for the nanocomposite and an 18.93 emu·g^-1 saturation magnetization value were obtained,indicating magnetic removal in a promising material for adsorption process.The nanocomposite regeneration capacity evaluated by magnetic recovery after 24 h suspension presented a high Pb^2+ion adsorptive capacity(98.4%)in the first cycle.Around 98%of the Pb^2+ions were adsorbed in the second cycle.In this way,the synthesized faujasite:cobalt ferrite nanocomposite reveals itself as a promising alternative in adsorption processes,aiming at a synergic effect of FAU zeolite high adsorptive activity and the cobalt ferrite nanoparticles magnetic activity,allowing for adsorbent recovery from the aqueous medium via magnetic force and successive adsorptive cycles.

Melt Extrusion of Environmentally Friendly Poly(L-lactic acid)/Sodium Metabisulfite Films for Antimicrobial Packaging Applications

Food packaging materials compounded with antimicrobial additives can substantially diminish the incidence of foodborne diseases.Here,poly(L-lactic acid)(PLA)films containing sodium metabisulfite(NaM)were produced by melt extrusion as an attempt to develop a new biodegradable material with antimicrobial properties for packaging.Life cycle assessment(LCA)simulations revealed that the environmental footprints of the PLA film did not change upon NaM addition,and that NaM is more eco-friendly than silver nanoparticles.The PLA/NaM films with NaM content varying from 0.5 to 5.0 wt.%were characterized by differential scanning calorimetry(DSC),thermogravimetric analysis(TGA),and optical and mechanical properties determinations.The optical properties were sustained after the addition of NaM,but high NaM contents degraded the light transparence of the PLA matrix at some extent.The thermal stability and tensile properties of the PLA film decreased proportionally to the NaM content,while no changes were observed on Tg,Tm and Xc,as determined by DSC.Agar diffusion tests revealed that the PLA/NaM films had no antimicrobial activity on Saccharomyces cerevisiae at 35°C,which was related to the limited migration of NaM from the glassy PLA matrix.The biodegradable PLA films compounded with NaM through melt extrusion display adequate optical,thermal,and mechanical properties to cover most food packaging applications,representing an essential step toward the development of eco-friendly packaging materials that can potentially exhibit an antimicrobially active surface.