Alexandre Giacobbo

Nanofiltration for the Recovery of Low Molecular Weight Polysaccharides and Polyphenols from Winery Effluents

A wide range of nanofiltration membranes are investigated for the fractionation of a winery effluent and recovery of the polysaccharides of low molecular weight and of the polyphenols. Permeation experiments were carried out with three laboratory-made cellulose acetate membranes and two commercial membranes: NF270 membrane supplied by Filmtec Corp., Minneapolis, MN (USA) and ETNA01PP membrane supplied by Alfa Laval, Nakskov, Denmark. The five membranes were characterized by the rejection coefficients to a set of reference solutes and evaluated in terms of the rejection coefficients to polysaccharides, polyphenols, conductivity and total organic carbon. The rejection coefficients to polyphenols were overall lower than the ones to polysaccharides, meaning that the polyphenols permeate preferentially through all the membranes. Among these membranes, the NF270 membrane displayed the highest rejection coefficients for all parameters evaluated, with rejections in the order of 93.8% and 99% for polyphenols and polysaccharides, respectively. On the other hand, the ETNA01PP membrane presented the lowest rejection coefficients: around 27% to polyphenols and 72% to polysaccharides.

The effect of sanitary landfill leachate aging on the biological treatment and assessment of photoelectrooxidation as a pre-treatment process

The sanitary landfill leachate is a dark liquid, of highly variable composition, with recalcitrant features that hamper conventional biological treatment. The physical-chemical characteristics of the leachate along the landfill aging, as well as their effects on the efficiency of the conventional treatment, were evaluated at this paper. The feasibility of photoelectrooxidation process as an alternative technique for treatment of landfill leachates was also determined. Photoelectrooxidation experiments were conducted in a bench-scale reactor. Analysis of the raw leachate revealed many critical parameters demonstrating that the recalcitrance of leachate tends to increase with time, directly influencing the decline in efficiency of the conventional treatment currently employed. The effects of current density and lamp power were investigated. Using a 400 W power lamp and a current density of 31.5 mA cm(-)(2), 53% and 61% efficiency for the removal of ammoniacal nitrogen and chemical oxygen demand were respectively achieved by applying photoelectrooxidation process. With the removal of these pollutants, downstream biological treatment should be improved. These results demonstrate that photoelectrooxidation is a feasible technique for the treatment of sanitary landfill leachate, even considering this effluents high resistance to treatment.

Ultrafiltration Based Process for the Recovery of Polysaccharides and Polyphenols from Winery Effluents

Winery effluents have a high pollution potential, especially those effluents that are obtained from the second racking. However, these effluents are rich in phenolic compounds and polysaccharides and can be potential sources for the recovery of these compounds. Therefore, a process was developed in this study to reduce the pollution potential of the winery effluents from the second racking and to recover the polyphenols and polysaccharides from the effluents by utilizing ultrafiltration (UF) and sedimentation operations. The sedimentation was optimized by varying the pH from 3.8 to 8.0, while the UF experiments were optimized by varying the transmembrane pressure from 0.5 to 4.0 bar and the feed circulation velocity from 0.44 to 0.87 ms−1. This process provided a permeate stream with a reduction in the TOC content by 56.6%, while the polyphenols and the polysaccharides in the concentrate stream were concentrated by 6 times and 5 times, respectively.

Integration of membrane bioreactor and advanced oxidation processes for water recovery in leather industry

AbstractNowadays, the conventional tannery wastewater treatment is not established in order to obtain water in such a quality that it could be reused in the same process. This study was then carried out in order to study an integrated wastewater treatment system, membrane bioreactor–photoelectrooxidation (MBR–PEO), for the final polishing of tannery wastewater. MBR is responsible for the remaining biochemical oxygen demand removal, while the refractory matter, quantified as chemical oxygen demand, is removed by PEO. This treatment configuration has provided two wastewater streams with quality standards for reuse as process water. The wastewater treated by the MBR could be reused in beamhouse operations, while the wastewater treated by the integrated MBR–PEO processes could be recycled for the tanyard and re-tanning steps due to its appreciable quality.

Membrane separation processes applied to the treatment of effluents from nanoceramic coating operations

In this work, the use of membrane separation processes (MSP) for the treatment of a synthetic effluent from a nanoceramic coating line was evaluated. Three MSP were tested: electrodialysis, microfiltration, and nanofiltration (NF). The presence of zirconium, a chemical element able to combine with different compounds producing complexes, and pH variations in the nanoceramic effluent are responsible for the different efficiency levels of the MSP in treating this effluent. The better results were reached with NF, making this process an option for the treatment of this new effluent.

Concentration Polarization in Ultrafiltration/Nanofiltration for the Recovery of Polyphenols from Winery Wastewaters

Concentration polarization is intrinsically associated with the selective character of membranes and often means flux decline and which causes a subsequent decrease of ultrafiltration and nanofiltration performance. More important is the fact that it acts as a precursor of membrane fouling and creates severe fouling problems in the longer times range. The quantification of its dependence on the operating parameters of cross-flow velocities and transmembrane pressures makes recourse to the film theory to introduce mass-transfer coefficients that generally are calculated by dimensionless correlations of the Sherwood number as a function of the Reynolds and Schmidt numbers. In the present work, the mass-transfer coefficients are obtained through the fitting of experimental results by the pressure variation method. The ultrafiltration/nanofiltration of the winery wastewaters from the racking operation is carried out with the membranes ETNA 01PP (Alfa Laval) and NF 270 (Dow Filmtec) under a wide range of cross-flow velocities and transmembrane pressures up to 15 bar.

Application of reverse osmosis to petrochemical industry wastewater treatment aimed at water reuse

Purpose The purpose of this paper is to apply reverse osmosis (RO) to the treatment of industrial wastewater from a large petrochemical complex in Southern Brazil, in order to verify the conditions of liquid effluent reuse and improve them, especially to reduce the consumption of natural water by some production structures such as boilers and cooling towers. Design/methodology/approach The petrochemical wastewater was submitted to pretreatment using a sand filter and activated carbon filters. Tests were conducted using RO equipment with a production capacity of 0.25 m3h−1 composed of a spiral membrane module with a membrane area of 7.2 m². Pressures of 8, 12 and 15 bar were applied with reject flow maintained constant at 10 Lm−1. Findings The experiment results indicated optimum RO performance since more than 90 percent extraction was obtained for most of the compounds present in the petrochemical wastewater. Originality/value By checking the aspects involved, as well as providing some relevant considerations about, this study promotes the application of RO to get a satisfactory water reuse in similar industries, thereby decreasing both the volume of water extracted from wellsprings and the amount of wastewater released into water bodies.