No abstract

The increasing interest in environment friendly products and processes has encouraged studies on the production of polymers from renewable sources. In this context, poly(ethylene 2,5‐furandicarboxylate) − PEF − is regarded as a potential alternative for poly(ethylene terephthalate) − PET − resins. However, despite the increasing number of studies on PEF synthesis and characterization, there is still room for comparisons between processes used to produce PEF and PET and between some characteristics of the produced resins. For this reason, in the present work PEF was produced through direct esterification and through transesterification, whilst PET was synthesized through transesterification, to allow comparative analyses of the respective process performances. Results indicate that PEF can be produced at milder and simpler operation conditions, although PEF processing is much more difficult, since PEF is less stable to heat, melts at lower temperatures, is more crystalline and is much more rigid than PET, indicating that appropriate modification of PEF resins is needed for the effective replacement of PET in real industrial applications.

The combination of suspended activated carbon (AC) and submerged microfiltration (SMF) processes was applied to polish a biotreated effluent generated in a refinery industry. Preliminary results indicated that Norit 1240 W AC was more suitable than Carbomafra AC brand for Total Organic Carbon (TOC) removal due to the highest Freundlich adsorption constant value (1.97 ± 0.42 and 0.96 ± 0.23 (mg/g)(L/mg)1/n, respectively), thus the first one was used in the combined system. Among all particle sizes of AC tested (0.041–1.01 mm), AC/SMF system was better performed, according to permeation flux, when applying granular AC instead of the powder one. On the other hand, the best response regarding TOC removal and Absorbance at 254 nm (ABS254 nm) reduction were observed when applying powder AC (89 and 97%, respectively). Statistical analysis with Two-sample T-test (p-value <0.05) endorsed the need of both air purge (20 L/h) and backwash strategies (8 min of permeation and 10 seconds of backwash) to diminish fouling occurrence in the SMF system. Finally, it was found that 2 g/L of Norit 1240 W PAC (0.041 mm particle size) condition fitted the effluent to further EDR process (3.4 mg/L TOC) with consistent normalized permeate flux after 5 h of permeation (0.76 ± 0.1 J/J0).