No abstract

The membrane process of ultrafiltration (UF) has been investigated as a pretreatment previous to the further recovery and concentration of phenolic compounds from residual table olives fermentation brines. Two UF membranes were tested: a permanently hydrophilic polyethersulfone (PES) membrane with a molecular weight cutoff (MWCO) of 30 kDa and a PES membrane with a MWCO of 5 kDa. Transmembrane pressure and 2 crossflow velocity were varied from 1 to 3 bar and from 2.2 to 3.7 m•s-1 , respectively. The best membrane in terms of permeate flux and selectivity was that with MWCO of 5 kDa and the best operating conditions were transmembrane pressure of 3 bar and crossflow velocity of 2.2 m•s-1. In these conditions permeate flux was 21.6 L•h-1 •m-2 , while the rejection of COD and phenolic compounds were 50.0% and 21.9%, respectively and the removal of color and turbidity was almost complete. In addition, an alkaline cleaning protocol was proposed, which was effective to restore the initial permeability of the selected membrane.

Full-scale wastewater treatment facilities are not able to prevent microplastics (MPs) from discharging into natural waters and they are also associated with the land application of the sludge. This study evaluates the distribution of microfibers (MFs) in a lab-scale sequencing batch reactor (SBR) fed by synthetic wastewater (SW) for 93 days. The MFs were analyzed through optical microscopy in the mixed liquor (ML) and the effluent, and sulfuric acid digestion was applied to discriminate between natural and synthetic MFs (i.e., MPs). The results of the optical microscopy analyses were further validated through FTIR spectroscopy. A model describing the evolution over time of the MF concentration in the ML was created, accounting for the MFs entering the system through the SW and atmospheric deposition. The ratio between the MF concentration in the ML and the effluent was 1409 ± 781, demonstrating that MFs settle with the sludge. Consistently, in the ML, 64.9% of the recovered MFs were smaller than 1000 µm (average size 968 µm), while in the effluent, 76.1% of MFs were smaller than 1000 µm (average size 772 µm). Overall, 72% of MFs recovered from the ML were natural fibers and sulfuric acid digestion was successful in eliminating the natural MFs.

ElsevierCarbonell Alcaina, C.; Corbatón Báguena, MJ.; Alvarez Blanco, S.; Bes-Piá, M.; Mendoza Roca, JA.; Pastor Alcañiz, L. (2016). Determination of fouling mechanisms in polymeric ultrafiltration membranes using residual brines from

No abstract