Influence of the operating parameters on the flux during microfiltration of the steepwater in the starch industry

The subject of the work is the possibility of applying microfiltration through a ceramic tubular membrane with 100 nm pore sizes to the steepwater obtained in the production process of com starch. The dry matter content should be reduced in the steepwater permeate. Thus the consumption of the process water would be reduced, the nutrients from the steepwater could be exploited as feed and the wastewater problem would consequently be solved. The objective of the work was to examine the influence of the operating parameters on the permeate flux during steepwater microfiltration. The parameters that vary in the course of microfiltration, were the transmembrane pressur and flow rate, while the permeate flux and dry matter content of the permeate and retentate were the dependent parameters, constantly monitored during the process. Another objective of this study was to investigate the influence of static turbulence promoter on the permeate flux during steepwater microfiltration. Static mixers enhance permeate flux, thus the microfiltration can be performed longer. As a result of the statistical analysis, the optimal conditions for steepwater microfiltration were determined. The maximum value of the permeate flux without mixer (25 lm"2 h"') was achieved at a pressure of 2 bars and a flow rate around 100 lh"1 . With the use of static mixer the flux is 2,5 times higher compared to the one obtained without the mixer. The dry matter content of the permeat after 2.5 hours of mucrofiltration was lowered by 40%

Separation of non-sucrosecompounds from the inermediate products of sugar crystallization using ultrafiltration

U radu su ispitane mogucnosti separacaije nesaharoznih jedinjenja ultrafiltracijom iz rastvora B i C šecera sadržaja suve materije 60 i 30 oBx. Eksperimentalna ispitivanja su izvedena na keramickim membrana sa otvorom pora od 20 i 5 nm, bez i sa primenom statickog mešaca kao promotora turbulencije. Tokom recirkulacije i koncentrovanja napojne smeše pracen je uticaj nezavisno promenljivih (transmembranskog pritiska, protoka, temperature i vremena trajanja procesa) na fluks, boju, mutnocu i kvocijent cistoce permeta. Ispitan je uticaj statickog mešaca na prljanje membrane, na potrošnju energije i smanjenja proizvodnih troškova. Eksperimentalni rezultati su jasno pokazali da se najveca razlika u vrednosti fluksa permeata rastvora B šecera dobija kada se uporedi nacin rada bez i sa upotrebom mešaca. Ta razlika iznosi 30% na 80oC, odn. 65% kada se temperatura održava na 70oC. Pri ultrafiltraciji rastvora C šecera, koji sadrži mnogostruko vecu kolicinu nesaharoznih jedinjenja, registruje se brža koncentraciona polarizacija, te se pri istim uslovima postiže za 70% manji fluks od fluksa permeata rastvora B šecera. Sadržaj saharoze permeata i retentata se ne menja tokom ultrafiltracije, nema merljive retencije saharoze, što je presudno za buducu primenu ovog separacionog postupka u industriju šecera. Dekoloracija rastvora B šecera bez upotrebe mešaca ?? na nivou 40%, ? postiže se na pritisku nižem od 6 bar i protoku od 250 L/h. Upotrebom mešaca se efekat dekoloracije poboljšava za oko 60%, i to pri protoku ispod 200 L/h. Izdvajanje bojenih materija pri ultrafiltraciji rastvora C šecera je prividno manje efikasno, jer ne prelazi vrednost od 25% racunato na napojnu smešu, mada se u apsolutnim vrednostima iz rastvora B i C šecera izdvoji približno ista kolicina bojenih materija (900 IJ). Ultrafiltracijom se mutnoca napojne smeše redukuje za 85%. Ispitivanja prljanja membrane pri ultrafiltraciji su pokazala da koncentraciona polarizacija i formiranje sloja sastavljenog od nesaharoznih jedinjenja na površini membrane predstavljaju dominantan udeo ukupnog hidraulicnog otpora. U membrani sa otvorom pora 20 nm, tokom ultrafiltracije meduproizvoda f?ze kristalizacije, otpor poraste usled prljanja za 20 – 50 puta, a u membrani sa otvorom pora 5 nm za 100 – 300 puta u odnosu na otpor ciste membrane. Korišcenje mešaca je opravdano u intervalu gubitaka hidraulicke snage od 0 – 7 W, jer se time postiže povecanje fluksa i do 60%. Pri vecim gubicima hidraulicne snage, odn. pri vecim brzinama proticanja, nivo turbulencije u praznoj cevi je znacajan, tako da se i bez upotrebe mešaca registruju vece vrednosti fluksa. Povecanje stepena koncentrovanja napojne smeše sa 1,0 na 1,2 prati smanjenje ukupnih prizvodnih troškova u opsegu od 30 – 77% kada se proces ultrafiltracije realizuje uz upotrebu mešaca.This work presents the study of possibility to separate of non-sucrose compounds from B and C sugar solutions, with a dry matter content of 60 and 30 oBx by ultrafiltration. Experimental investigations were performed on ceramic tubular 20 and 5 nm pore diameters membranes, with and without kenics static mixer as turbulence promoter. The influence of independent parameters (transmembrane pressure, flow rate, temperature and ultrafiltration time duration) on permetate flux, colour, turbidity and purity during feed recirculation and feed concentration were examined. The efficiency of static mixer was investigated on membrane fouling, on energy consumption and on economical calculations. The experimental results showed that, the greatest flux difference of B sugar solution was obtained when the operation mode was with a static mixer in comparation to the operation mode without one, showing 30% difference at temperature 80 oC and 65% at 70 oC. While ultrafiltering the C sugar solution, which contains more non-sucrose compounds, a faster concentration polarization was noticed, thus at the same working conditions 70% less flux was reached in comparison with to the B sugar solution permeate flux. The permeate and retentate sugar content did not changed during ultrafiltration, there is no measurable retention of sucrose, which is important for the implementation of this type of separation into sugar industry. The decoloration of B sugar solution without static mixer is 40%, and can be reached at transmembrane pressure bellow 6 bar and flow rate of 250 L/h. By using a static mixer the decoloration effect is improved for 60%, when flow rate is held bellow 200 L/h. The separation of coloured compounds during ultrafiltration of C sugar solution is apparently less efficient since the value did not reach 25% calculated on feed, even though measured in absolute values the same level of coloured compounds was separated from B and C sugar solution (900 IU). The turbidity of B and C solution was reduced by ultrafiltration for 85%. The examinations of membrane fouling during ultrafiltration showed that the concentration polarization and formation of a non-sucrose compound layer on the membrane surface are dominant parts of the total hydraulic resistance. During ultrafiltration of intermediate products of sugar crystallization using 20 nm pore membrane diameter the resistance increased for 20 – 50 times due to fouling. Using a 5 nm pore diameter membrane the resistance increased for 100 – 300 times comparing to clean membrane. The use of static mixer is justified when 0 – 7 W loss of hydraulic power was determined, because in that interval a 60% flux increase was detected. At higher levels of hydraulic power loss, and at higher values of flow rates the turbulency in empty tubular membrane is significant, so even without using static mixers higher values of flux are detected. When a static mixer was used with the increase of volume concentration ratio from 1,0 to 1,2 the total production costs decreased in a range of 30 – 77%

Investigation of ultrafiltration parameters of different organic load wastewater types

Almost a third of Earth’s freshwater resources are used by municipalities, agriculture and industries and therefore very large quantities of wastewater are generated and discharged into surface water or groundwater. If discharged inadequately and without previous treatment, wastewater can cause chemical pollution, affect aquatic life as well as human health and have a negative impact on the environment. An emerging technology for wastewater treatment is the membrane separation process due to the low cost, the use of ambient temperature, the low energy consumption compared to other traditional techniques, and the high selectivity of different separation mechanisms with compact design. In this study, ultrafiltration (UF) technique was investigated to treat wastewater with different organic loads. The effects of the stirring and a three-dimensional (3D) printed spacer, integrated into the UF cell were analyzed on the permeate fluxes, membrane rejections of turbidity, conductivity and chemical oxygen demand (COD)

Investigation of ultrafiltration parameters of different organic load wastewater types

Almost a third of Earth’s freshwater resources are used by municipalities, agriculture and industries and therefore very large quantities of wastewater are generated and discharged into surface water or groundwater. If discharged inadequately and without previous treatment, wastewater can cause chemical pollution, affect aquatic life as well as human health and have a negative impact on the environment. An emerging technology for wastewater treatment is the membrane separation process due to the low cost, the use of ambient temperature, the low energy consumption compared to other traditional techniques, and the high selectivity of different separation mechanisms with compact design. In this study, ultrafiltration (UF) technique was investigated to treat wastewater with different organic loads. The effects of the stirring and a three-dimensional (3D) printed spacer, integrated into the UF cell were analyzed on the permeate fluxes, membrane rejections of turbidity, conductivity and chemical oxygen demand (COD)

Physical properties of dough for cookies with chestnut flour

A challenge for food producers is certainly to find suitable flour that can replace wheat flour in the production of flour–based products. Chestnut flour can be adequate substitute for wheat flour in the production of gluten–free flour confectionary products, due to high starch and sugar content. The objective of this work was to characterize physical changes, rheological and textural properties of dough for cookies with chestnut flour. The control dough was only with wheat flour. The substitution of wheat flour with chestnut flour for examined dough samples was at three different levels (20, 40 and 60%). Moisture of the dough was 22%. Dynamic oscillatory measurements describe all dough samples as typical viscoelastic systems with dominant elastic modulus G' over viscous modulus G". The modulus ratio (tan δ=G"/G') decreased with increase in amount of chestnut flour. Also, the dough compliance (J) determined by creep and recovery curves decreased, thus more chestnut flour resulted in more brittle consistency of the dough. Texture determination confirmed the rheological results. Resistance to extension of the control dough sample was the highest, as well as dough extensibility. Application of chestnut flour and increase in its amount reduced these texture parameters for dough samples. Optimal physical properties of dough were achieved with low amounts of chestnut flour of 20%

Solid-phase extraction as promising sample preparation method for compound of emerging concerns analysis

Today’s environment is under the influence of numerous substances and most of them are not covered by current national and international regulations. Substances that are classified as contaminants of emerging concern, CECs, are not regulated nor systematically controlled in the environment, and they belong to the different chemical classes such as pesticides in current use, pharmaceutically active compounds (PhACs), personal care products, illicit drugs, hormones, micro- and nano-plastics, per- and poly-fluoroalkyl substances (PFAS), and many others. Once released CECs end up in surface water where they can be either accumulated or transported to the other environmental compartments, i.e. soil (by irrigation), underground water, or drinking water. The aim of the research was to investigate the efficiency of different selected solid-phase extraction (SPE) cartridges for preparation of water samples for simultaneous analysis of several CECs. For this purpose, a model mix solution of selected CECs in concentration relevant to environmental appearance was used. The selected CECs (14 PhACs, 11 pesticides in current use, and 4 PFAS) represented emerging contaminants with different properties, including polarities, and varying adverse effect on the environment and human health. Different types of sorbents were investigated: (i) commercial single-layer HLB, (ii) homemade multi-layer I: HLB plus a mix of WAX, WCX, and PPL, and (iii) multi-layer II: mix of WAX, WCX, and PPL plus HLB. The results revealed that the single-layer sorbent showed better efficiency in extraction of the analyzed CECs. Multi-layer sorbent should be further investigated to elucidate the possible reason for the poor extraction of some compounds, as development of a balanced extraction for a wider range of contaminants with different polarities, especially for non-target analysis of chemical residues, is required in order to capture the occurrence of the full profile of micropollutants

Physical properties of dough for cookies with chestnut flour

A challenge for food producers is certainly to find suitable flour that can replace wheat flour in the production of flour–based products. Chestnut flour can be adequate substitute for wheat flour in the production of gluten–free flour confectionary products, due to high starch and sugar content. The objective of this work was to characterize physical changes, rheological and textural properties of dough for cookies with chestnut flour. The control dough was only with wheat flour. The substitution of wheat flour with chestnut flour for examined dough samples was at three different levels (20, 40 and 60%). Moisture of the dough was 22%.Dynamic oscillatory measurements describe all dough samples as typical viscoelastic systems with dominant elastic modulus G' over viscous modulus G". The modulus ratio (tan δ=G"/G') decreased with increase in amount of chestnut flour. Also, the dough compliance (J) determined by creep and recovery curves decreased, thus more chestnut flour resulted in more brittle consistency of the dough. Texture determination confirmed the rheological results. Resistance to extension of the control dough sample was the highest, as well as dough extensibility. Application of chestnut flour and increase in its amount reduced these texture parameters for dough samples. Optimal physical properties of dough were achieved with low amounts of chestnut flour of 20%

Adsorption of ammonium using pomegranate peel as low-cost adsorbent

Naoufal Bellahsen1, Szabolcs Kertész2, Zita Šereš3, Cecilia Hodú