During our research
concentrations of quality wines were investigated by membrane separation on
nanofiltration and reverse osmosis membranes. The practicability of the process
was examined by experimental design in our laboratory experiments. The effects
of the operating parameters on the efficiency of the methods were analyzed,
from which the conclusion was drawn that the sugar content of the wines affects
the filtrate capacity considerably. This phenomenon was attributed to the
resistance appearing during the process. This resistance is the osmotic
pressure which is faced with the driving force. By the mathematical modeling of
the process - building up experimental and empirical relations - the answer for
the practical implementing was searched for. Our concrete model concentrates on
the connection between the changing of the osmotic pressure and the retained
molecules by the membrane. Monitoring of this connection is a primary criterion
when planning the optimal development of the process.
Authors:Attila Csighy, Andras Koris, and Gyula Vatai
Milk and dairy products contain a number of biological materials that are essential for the human body, for example proteins, lipids, vitamins and minerals. In this study the application of membrane filtration based milk partial demineralization is detailed. The main point of the partial demineralization is to reduce the monovalent ions (Na+, K+) but to keep the divalent ions (Ca2+, Mg2+) content. The experiments were carried out using laboratory ultra- and nanofiltration units. Comparing the separation behavior of the membranes it was found that the investigated membranes are suitable for the partial demineralization. The result of the Lowry test showed that the protein concentration is higher in the retentates of all membrane filtrations than in the permeates.
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:Szilvia Bánvölgyi, Eszter Dusza, Fiina K. Namukwambi, István Kiss, Éva Stefanovits-Bányai, and Gyula Vatai
Similarly to other industries wineries also increasingly attempt to minimize and utilize waste to protect our environment. The aim of this study was to determine the optimal parameters (temperature, solvent concentration, and time) of extracting total polyphenol content (TPC) from Tokaji Aszú marc using two different extraction solvents: ethanol–water and isopropanol–water (1:4 solid/liquid ratio). The extractions were achieved based on Central Composite Design with Response Surface Method (CCRD–RSM). The optimal extraction parameters in the case of ethanol–water solvent: 60 °C temperature, 59.5% ethanol concentration in solvent, 5 h. At these parameters the probable TPC concentration is 23966.2 uM GAE/L. The optimal extraction parameters in the case of isopropanol–water solvent: 60 °C temperature, 52% ethanol concentration in solvent, 5 h. At these parameters the probable TPC concentration is 7188.44 uM GAE/L. In both cases the binary solvent was better than the mono-solvent. Ethanol–water solvent was more efficient than the isopropanol–water solvent.