Authors:E. Márki, I. Vas-Vincze, L. Tóvári, and Gy. Vatai
One of the most important enriching materials at the processing of alimentary pastes is the egg, which usage is limited because of its water content. Removing water from liquid whole egg with membrane processes, such as ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) was applied for raising the solid content at a temperature of 25 °C at constant flow rate. The separation procedures were carried out on laboratory scale equipments. The initial solid content of the liquid whole egg was 24 refractive (Ref%). The effects of different recirculation flow rates and transmembrane pressure differences were investigated on the permeate flux of the liquid egg. The product had up to 30, 35.5 and 36 Ref% solids in case of UF, NF and RO, respectively. From the resistance data it is obvious, that the polarization layer resistances (RP) determine the values of the permeate flux. The total solid content of permeate was 0.3 and 0.1 Ref% in case of nanofiltration and reverse osmosis, respectively. On the basis of experiments main data of a continuous pilot scale system were calculated and simplified cost estimation was performed using recent economic data of year 2011.
Authors:Sz. Gy. Szerencsés, S. Beszédes, Zs. László, G. Veréb, D. Szalay, Zs. Hovorkáné Horváth, C. Hodúr, G. Rákhely, and Sz. Kertész
using a VSEP with UF and NF membranes. Membrane evaluation and selection started with contact angle measurements, followed by membranefiltration experiments in order to investigate the effects of operational parameters and compliance of the
Authors:Jesus Molina, Gyula Vatai, Eszter Fogarassy, and Erika Bekassy-Molnar
The problem of wastewater with high content of salt is a frequent problem for the environmental authorities, because the existing municipal and industrial wastewater treatments are incapable to remove effectively inorganic compounds. In this paper an attempt was made to report new results with reverse osmosis (RO) and nano-filtration (NF) membranes to remove salts from fermentation wastewater.The basic target of the experiments was to find an industrial membrane, which can separate salts from fermentation wastewater with a high efficiency and the concentration of the clean water should satisfy the environmental regulation: salt concentration ≤ 2500 mg/L and COD concentration ≤ 1200 mgO
/L. RO process exhibited good salt rejection and effective removal of organics. The other aim of this study was to model the osmotic pressure and permeate flux in the wastewater using basic expressions, like van’t Hoff law and Rautenbach equations. The combination of the above models with experiment based constants gave a good tool for modeling salty wastewater.
Authors:Sz. Szélpál, Zs. Kohány, E. Fogarassy, I. Galambos, A. Koris, J. Csanádi, Gy. Vatai, and C. Hodúr
The largest quantities of by-products of dairy processing originates from the cheese making. Whey proteins are used for animal feeding and human nutrition as well, for example in dry soups, infant formulas, and supplements. The fat components of the whey might impair its use. The aim of our experiments was to investigate the separation of the lipid fraction of whey. The microfiltration is said to be a gentle and energy efficient method for this task. During the measurements 0.2 μm microfiltration membranes were used and the membrane separation was enhanced by vibration, inserting static mixer and air sparging. The de-fatting efficiency, the retention of the whey components, the flux values, and the resistances in different combinations were compared in this paper.
Authors:S. Mondal, M. Berihun, M. Kovacs, G. Vatai, and A. Koris
Microscopic organisms play a vital role in the field of green technology. Among the genera fungi, the group of entomopathogens includes Beauveria bassiana, which has been found to have multifunctional applications. In this present research, we have attempted to partially purify chitinase from two strains of Beauveria bassiana (F881 and F911), each cultured in minimal media with 1% (w/v) colloidal chitin as well as in Sabouraud's dextrose media with 1% (w/v) colloidal chitin. The purification process was done with a setup of ceramic membranes, which comprises two stages, ultrafiltration (50 nm pore size membrane) and nanofiltration (MWCO 5 kDa). Furthermore, with the analysis of yield of enzymatically hydrolyzed NAG (N-acetyl glucosamine), resistance and fouling of the membrane were also studied.
Authors:Zs. Kiss, Sz. Kertész, C. Hodúr, G. Keszthelyi-Szabó, and Zs. László
Nowadays, the membrane filtration technique is a commonly used method for the separation of whey. The most significant limitation of membrane applications is fouling, which causes flux decline. During this work, regenerated cellulose membranes covered by TiO2-nanoparticles were investigated and applied to the separation of whey solution. Experiments were carried out in a dead-end ultrafiltration cell, and the changes in filtration parameters and the photocatalytic effects of the UV irradiated TiO2 modified membrane surface on the membrane fouling were examined. Our results showed that the water flux decreased with increasing TiO2 layer thickness, but the retention of turbidity and of COD increased. After separation, the membrane surface was cleaned by UV irradiation by means of photocatalytic oxidation. It was found that the original flux was recoverable, while the retention of the membrane decreased after cleaning.
Adsorption of radium was studied on glass and polyethylene from aqueous solutions containing 8–40 pg·dm–3224Ra and on membrane filters, glass and polyethylene bottles from waste and river waters containing 2–170 pg·dm–3226Ra. The adsorption from aqueous solutions was determined as a function of pH and composition of the solutions and interpreted as due to ion exchange of Ra2+ ions for counter ions in the electric double layer on glass and polyethylene or due to chemisorption of RaSO4 (RaCO3) ion pairs on glass. Borosilicate glass adsorbed radium substantially more than polyethylene. The adsorption of dissolved forms of radium from the waste and river waters during storage and membrane filtration of the waters was negligible, but a significant loss of particulate forms of radium was sometimes observed during the storage. It has been recommended to separate dissolved and particulate forms of radium soon after the sampling and to prefer polyethylene to glass as container material for storage of dissolved forms of radium.