Produção Nacional
Revisado por pares
Membrane processing of the Brazilian spirit Cachaça
2019; Wiley; Volume: 125; Issue: 3 Linguagem: Inglês
10.1002/jib.564
ISSN2050-0416
AutoresJoel R. Karp, Fabiane Hamerski, Vítor Renan da Silva, Adriane Bianchi Pedroni Medeiros,
Tópico(s)Nanocomposite Films for Food Packaging
ResumoJournal of the Institute of BrewingVolume 125, Issue 3 p. 383-388 Research articleFree Access Membrane processing of the Brazilian spirit Cachaça Joel R. Karp, Graduate Program in Mechanical and Materials Engineering, Federal University of Technology of Paraná, Department of Alencar Furtado St, Curitiba, Paraná, BrazilSearch for more papers by this authorFabiane Hamerski, Chemical Engineering Department, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, Curitiba, Paraná, BrazilSearch for more papers by this authorVítor R. da Silva, Corresponding Author vrenan@ufpr.br orcid.org/0000-0002-0109-4155 Chemical Engineering Department, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, Curitiba, Paraná, BrazilCorrespondence to: Vítor R. da Silva, Chemical Engineering Department, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, Curitiba, Paraná, Brazil. E-mail: vrenan@ufpr.brSearch for more papers by this authorAdriane B.P. Medeiros, Department of Bioprocess Engineering and Biotechnology, Av. Cel. Francisco H. dos Santos, Federal University of Paraná, Curitiba, Paraná, BrazilSearch for more papers by this author Joel R. Karp, Graduate Program in Mechanical and Materials Engineering, Federal University of Technology of Paraná, Department of Alencar Furtado St, Curitiba, Paraná, BrazilSearch for more papers by this authorFabiane Hamerski, Chemical Engineering Department, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, Curitiba, Paraná, BrazilSearch for more papers by this authorVítor R. da Silva, Corresponding Author vrenan@ufpr.br orcid.org/0000-0002-0109-4155 Chemical Engineering Department, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, Curitiba, Paraná, BrazilCorrespondence to: Vítor R. da Silva, Chemical Engineering Department, Federal University of Paraná, Av. Cel. Francisco H. dos Santos, Curitiba, Paraná, Brazil. E-mail: vrenan@ufpr.brSearch for more papers by this authorAdriane B.P. Medeiros, Department of Bioprocess Engineering and Biotechnology, Av. Cel. Francisco H. dos Santos, Federal University of Paraná, Curitiba, Paraná, BrazilSearch for more papers by this author First published: 18 June 2019 https://doi.org/10.1002/jib.564Citations: 1AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Abstract As an alternative technology for the production of cachaça, fermented sugar cane must was clarified by ceramic α-alumina membranes, followed by water removal by pervaporation using a silk sericin/polyvinylalcohol (PVA) non-porous membrane. The high solute content in the fermented must resulted in fouling and concentration polarisation in both microfiltration and pervaporation. The hydrophilicity of the sericin/PVA blends was exploited in ethanol and aroma concentration, at an optimal temperature of 20°C, resulting in a separation factor and permeation flux of 3.7 and 958.3 g/m2 h. An aroma profile was performed using GC SPME/headspace and GC-MS, analysing the content of ethanol, 3-methyl-1-butanol, 2-methyl-1-butanol, ethyl lactate, isoamyl acetate, ethyl octanoate and ethyl laurate. The results show that the volatiles present in the fermented sugar cane must were concentrated, with recoveries of 93.9 and 94.3% of the principal aromatic compounds. © 2019 The Institute of Brewing & Distilling Introduction Alcoholic beverages are a broad class of drinks containing alcohol from fermentation or distillation 1, 2. Although most spirits relate to a specific country or region, international availability of these beverages has become increasingly common. One example is the Brazilian sugar cane spirit – cachaça – the world's third most consumed distilled beverage, after vodka and soju 3-5. Cachaça has an ethanol content of 38–48% (v/v) and is produced by distilling the fermented sugar cane juice 6. Currently, Brazil produces 1.4 billion litres of cachaça, of which <8% is exported 7. Therefore, this spirit has export potential, justifying the efforts made recently to expand its availability throughout the world 3, 8-12. Production of cachaça starts with the milling of sugar cane for juice extraction, followed by decantation and filtration. The purified sugar cane juice is then fermented 3. Ethanol and other volatiles (esters and higher alcohols) contribute to the flavour of cachaça 9-13. After fermentation, there is distillation in copper pot stills at high temperatures 4. There are some undesirable outcomes of distillation such as the degradation of heat-sensitive aromas 10 together with the formation of carcinogens such as ethyl carbamate (EC), whose presence in cachaça has been frequently reported 12-14. Although the origin of this compound is still under debate, distillation in copper stills promotes the formation of EC 13. This is of concern as in recent studies over 39% of the cachaça samples analysed were above the Brazilian legal specification, which limits the amount of EC to 210 μg/L 8. Accordingly, an alternative cachaça production process at lower temperatures would be promising, preserving the aromas but preventing the formation of EC. Among the techniques employed in the food industry, low-temperature membrane processing has been applied to ethanol solutions and alcoholic beverages 1, 15-21. Indeed, non-alcoholic beer of good quality has been produced by reverse osmosis with a hydrophilic membrane. Alcantara et al. 22 report that membrane processing has advantages for alcoholic beverages, as both the temperature and pressure are controlled. In addition to reverse osmosis, cross flow microfiltration and pervaporation have also been applied. Cross flow microfiltration involves the passage of a fluid through a porous membrane, which promotes clarification by retention of suspended solids with pressure difference as the driving force 22, 23. Pervaporation, on the other hand, is the selective permeation of species through a non-porous membrane followed by evaporation at the permeate side. The chemical potential gradient across the membrane acts as the driving force 15, 19, 21. The membranes employed in pervaporation can be either hydrophobic or hydrophilic and therefore applications such as ethanol dehydration and aroma recovery can be achieved by this process 16-18. Karp et al. 15 conducted ethanol dehydration assays with a water selective silk fibroin/polyvinylalcohol (PVA) membrane blends at 20°C. Silk sericin/PVA blends were also employed, with separation factors up to 190 at 60°C when the feed water content was ~12 wt% 19. Several studies with aqueous ethanol solutions evaluated the influence of the feed composition, reporting the trade-off effect on the permeation flux and separation factor, such that for hydrophilic membranes higher feed water content increase the permeation flux, owing to intense membrane swelling. The efficiency of the process decreases, since the permeation of all components in the feed is facilitated 15, 17, 19, 21. The present study reports a novel approach in cachaça production by membrane processing. The evaluation of pervaporation in cachaça production was performed by coupling to a preliminary clarification stage by microfiltration. Additionally, the influence of temperature and pressure on the pervaporation process was assessed by analysis of the permeation flux and separation factor. The proposed cachaça process was compared with traditional distillation by analysis of the volatiles and aromatic profile of the samples. Materials and Methods The samples of fermented organic sugar cane must were kindly donated by the Porto Morretes company (Morretes, Paraná, Brazil). Two different approaches were used in this study regarding the use of membrane processing in the cachaça production (Figure 1). The following sections contain descriptions of the membrane processes employed in this work. Figure 1Open in figure viewerPowerPoint Proposed cachaça production processes. Clarification This procedure seeks to remove suspended solids and other impurities from the fermented must, previously treated by decantation at 5°C for 24 h. The clarification process was conducted by microfiltration, carried out in a cross flow microfiltration unit, described by Silva et al. 24. An α-alumina membrane (Fairey Ceramic, UK) with 0.44 μm pore diameter and a permeation area of 0.06 m2 was used. The pilot plant consists of a stainless steel (AISI 304) feed tank with a capacity of 20 L, followed by a positive displacement pump geared with a three phase induction motor (WEG, Springer FP7 1263, Brazil) with a frequency control for flow adjustment. The transmembrane pressure, measured by gauges placed before and after the membrane shell, was controlled by a needle valve. At first, clarification experiments were made in order to determine the optimal transmembrane pressure, which corresponds to the highest clarification flux. This analysis was carried out under full recycle regime, in which both permeate and retentate streams returned to the system. The transmembrane pressure varied from 0.275 to 0.775 bar. Then, a batch clarification was conducted, in which 600 L/h of fermented must flowed through the system. The influence of permeation time on the clarification flux calculated by equation 1 was analysed. All of the clarification assays were conducted at room temperature. (1)where JC(t) is the clarification flux (kg/m2 h), MC is the clarified must mass (kg), SC is the permeation area of the microfiltration membrane and t is the clarification time (h). The efficiency of the clarification process represents the extent of the removal of suspended solids, usually expressed as a coefficient of rejection (CR) and calculated according to equation 2. The suspended solids in the clarified and fermented must samples were estimated by turbidity measurements (POLICONTROL, AP 2000), after calibration with pattern suspensions with turbidities of 99% of the suspended solids present in the feed. The employment of the microfiltration technique with ceramic membrane has, therefore, yielded a product of better quality owing to an increase in the concentration of polarised substances 26. However, the lower turbidity values of the feed promoted an increase of >15% of the permeation flux with the transmembrane pressure. This endorses the observation made earlier in this study, that high content of suspended solids results in more intense fouling and polarisation of concentration. Pervaporation As shown in Figure 2, these results endorse the hydrophilic properties of the silk sericin/PVA membranes blends, since under all operating conditions, the volatiles content in the permeate stream was lower in comparison with the feed solution. Figure 2 also reports that the solute influenced the permeate composition only at 20°C, with a total volatiles content of 2.2 and 0.7 mol% for the fermented and clarified must, respectively. Curiously, at 60°C, the solute did not show any influence on the permeate composition, since a total volatiles content of 1.5 mol% was achieved for both the fermented and clarified must. A more thorough analysis was made in conjunction with the permeation flux and separation factor, according to the data presented in Table 1. Clearly, the solutes present in the fermented must influence the performance of the pervaporation assays. At 20°C, the presence of solutes caused the permeation flux to decrease by 18.8%, whereas at 60°C the decay was even more substantial at ~70%. Such outcomes are expected, since the fouling phenomena which drastically reduce the permeation flux is due to the presence of solutes 26. Regarding the influence of the suspended solids in the separation factor, as previously discussed, a curious observation was made, since it appears to be opposite in comparison with the permeation flux. The removal of solute promoted a high increase in the separation factor only at 20°C, whereas at 60°C the efficiency of the process remained unaltered. Apparently, when the increase in permeation flux owing to the solute removal is high, the separation factor remains unaltered. Similarly, an increase in the pervaporation efficiency tends to be accompanied by a smaller variation of the permeation flux. This unexpected observation can be related to the sorption/diffusion theory, widely applied in pervaporation applications 16. It states that the overall process of pervaporation comprises two major steps: sorption at the membrane/feed solution interface; diffusion across the thickness of the membrane. It is a common (although not definitive) observation, that the permeation flux is mainly controlled by diffusion, whereas the membranes selectivity is determined by the sorption process 18, 19. Therefore, the different behaviours regarding the permeation flux and separation factor might be attributed to the specific influence of fouling in the individual sorption and diffusion steps. That is, a high influence of species diffusion across the membrane is accompanied by a moderate or non-existent influence in the sorption phenomenon and vice-versa. Aromatic profile The total volatiles content is insufficient for describing with precision the efficiency of the pervaporation process, since individual compounds can interact differently with the membrane. Firstly, the ethanol content as a weight (%) of the total volatiles content needs to be determined. Such an evaluation was made according to the SPME/headspace analysis (Table 2). The ethanol content in the fermented and clarified must was very similar, with values of 65.0 and 70.1 (wt%). However, aromas are present in much larger amounts in the must samples in comparison with the commercial sample. In summary, over 86% of the aromatic compounds present in the fermented must were degraded in the traditional cachaça processing. Previous work with SPME/headspace analysis indicated the presence of diverse volatiles, but their quantification by comparison of the individual retention times with pure standards could be difficult. Therefore, the GC-MS technique was employed to thoroughly evaluate the aromatic profile of the fermented must and permeate samples, analysing the concentration of each aroma individually. Figure 5 shows the main aromas identified in the fermented must, including 3-methyl-1-butanol, 2-methyl-1-butanol, ethyl lactate, isoamyl acetate, ethyl octanoate and ethyl laurate. Recent studies reported a similar composition for samples of unaged distilled cachaça, with the exception of ethyl acetate, which was not present in the fermented must 3, 4, 8, 10, 11. Even considering the aroma degradation, it is expected that more compounds would be quantified in the distilled commercial cachaça. Figure 5Open in figure viewerPowerPoint Individual content of the aromatic compounds present in the fermented must and permeate samples (20 and 60°C). Figure 5 shows the aromatic profile of the permeate samples, obtained at 20 and 60°C from the pervaporation of the clarified must. Clearly, the hydrophilicity of the silk sericin/PVA membrane blend is confirmed, since all the aromas are much more concentrated in the fermented must in comparison with the permeate. For instance, with 3-methyl-1-butanol and the aroma with the highest signal in the must, 12.1% was removed from the feed solution by pervaporation at 60°C, while at 20°C only 6.1% was removed. 2-Methyl-1-butanol presented similar results, with removal percentages of 10.5 and 5.7% at 60 and 20°C. Regarding the other analysed aroma compounds, no selective permeation occurred at 20 and 60°C, indicating that the membrane processing does not degrade the compounds. Another important observation is that the individual volatiles concentration follows the same tendency as the total volatiles content, in such a way that lower temperatures improved the process efficiency. Finally, the membrane processing approach has an advantage in terms of quality, since the pervaporation process did not promote the formation of EC, as distillation would have. The presence of methanol is not a concern, since there was no identification of this compound. The application of hydrophilic membranes for concentrating alcoholic beverages by pervaporation has not been conducted before. Recent studies regarding the water removal by pervaporation focused on solvent dehydration 15, 17 and water desalination 27; therefore, the interactions of aromatic compounds with this kind of membrane are still unaccounted for. However, researchers were able to achieve improvements regarding the optimisation of the permeation flux for water removal through hydrophilic membranes. Liang et al. 28 obtained a permeation flux of 8.53 L/m2 h by enhancing the synthesis of hydrophilic PVA composite membranes. Therefore, in association with permeation flux optimisation, the exploited hydrophilicity of the silk sericin/PVA membrane blends present a novel processing technique within Brazilian spirit cachaça production. Conclusions A new approach in cachaça production has been proposed in the present study, employing microfiltration and pervaporation techniques. The concentration of the volatiles was confirmed in the aromatic profile, endorsing the technological potential of the low temperature membrane processing. The hydrophilicity of the silk sericin/polyvinylalcohol membrane blends was exploited, yielding an excellent performance for the individual aroma compounds analysed. Pervaporation at 20°C and 666.6 Pa preserved 93.9% and 94.3% of 3-methyl-1-butanol and 2-methyl-1-butanol, respectively. All other identified aroma compounds were not degraded by the proposed process. The clarification by microfiltration process was efficient, removing all of the suspended solids and other impurities. By its influence on the performance of the pervaporation assays, the clarification procedure was effective, allowing an appropriate volatile concentration at 20°C with a permeation flux of 958.3 g/m2 h and a separation factor of 3.7. Further process optimisation is required, improving the pervaporation efficiency and water removal from the clarified must. The novel membrane processing approach has potential for application not just in cachaça production, but with spirits in general. Acknowledgements Support from Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brazil and the Porto Morretes company are acknowledged. REFERENCES 1Gnansounou, E., and Dauriat, A. (2005) Ethanol fuel from biomass: A review, J. Sci. Ind. Res. 64, 809– 821. CASWeb of Science®Google Scholar 2Schwan, R. F., da Mendonça Silva, J. J. Jr., Rodrigues, V., and Wheals, A. E. (2001) Microbiology and physiology of Cachaça (aguardente) fermentations, Anton. Leeuw. 79, 89– 96. https://doi.org/10.1023/A:1010225117654CrossrefCASPubMedWeb of Science®Google Scholar 3de Souza, P. P., Cardeal, Z. d. L., Augusti, R., Morrison, P., and Marriott, P. J. (2009) Determination of volatile compounds in Brazilian distilled cachaça by using comprehensive two-dimensional gas chromatography and effects of production pathways, J. Chromatogr. A 1216, 2881– 2890. https://doi.org/10.1016/j.chroma.2008.10.061CrossrefCASPubMedWeb of Science®Google Scholar 4Scanavini, H. F. A., Ceriani, R., and Meirelles, A. J. A. (2012) Cachaça distillation investigated on the basis of model systems, Braz. J. Chem. Eng. 29, 429– 440. https://doi.org/10.1590/S0104-66322012000200022CrossrefCASWeb of Science®Google Scholar 5de Souza, A. P. G., Vicente, M. d. A., Klein, R. C., Fietto, L. G., Coutrim, M. X., Afonso, R. J. d. C. F., Araújo, L. D., da Silsa, P. H. A., Bouillet, L. E. M., Castro, I. M., and Brandão, R. L. (2012) Strategies to select yeast starters cultures for production of flavor compounds in cachaça fermentations, Ant. Leeuw. 101, 379– 392. https://doi.org/10.1007/s10482-011-9643-5CrossrefPubMedWeb of Science®Google Scholar 6 Ministry of Agriculture, Livestock and Supply, Brazil (2005) Instruction no. 13. (accessed 26 December 2017). Google Scholar 7Barbosa, E. A., Souza, M. T., Diniz, R. H. S., Godoy-Santos, F., Faria-Oliveira, F., Correa, L. F. M., Alvarez, F., Coutrim, M. X., Afonso, R. J. C. F., Castro, I. M., and Brandão, R. L. (2016) Quality improvement and geographical indication of cachaça (Brazilian spirit) by using locally selected yeast strains, J. Appl. Microbiol. 121, 1038– 1051. https://doi.org/10.1111/jam.13216Wiley Online LibraryCASPubMedWeb of Science®Google Scholar 8Bortoletto, A. M., and Alcarde, A. R. (2015) Assessment of chemical quality of Brazilian sugar cane spirits and cachaças, Food Control 54, 1– 6. https://doi.org/10.1016/j.foodcont.2015.01.030CrossrefCASWeb of Science®Google Scholar 9Rota, M. B., Piggott, J. R., and Faria, J. B. (2013) Sensory profile and acceptability of traditional and double-distilled cachaça aged in oak casks, J. Inst. Brew. 119, 251– 257. https://doi.org/10.1002/jib.88Wiley Online LibraryWeb of Science®Google Scholar 10Santiago, W. D., Cardoso, M. G., Santiago, J. A., Teieira, M. L., Barbosa, R. B., Zacaroni, L. M., Sales, P. F., and Nelson, D. L. (2016) Physicochemical profile and determination of volatile compounds in cachaça stored in new oak (Quercus sp.), amburana (Amburana cearensis), jatoba (Hymenaeae carbouril), balsam (Myroxylon peruiferum) and peroba (Paratecoma peroba) casks by SPME-GC–MS, J. Inst. Brew. 122, 624– 634. https://doi.org/10.1002/jib.372Wiley Online LibraryCASWeb of Science®Google Scholar 11Nascimento, E. S. P., Cardoso, D. R., and Franco, D. W. (2008) Quantitative ester analysis in cachaça and distilled spirits by gas-chromatography–mass spectrometry (GC–MS), J. Agric. Food Chem. 56, 5488– 5493. https://pubs.acs.org/doi/full/10.1021/jf800551dCrossrefCASPubMedWeb of Science®Google Scholar 12Riachi, L. G., Santos, A., Moreira, R. F. A., and de Maria, C. A. B. (2014) A review of ethyl carbamate and polycyclic aromatic hydrocarbon contamination risk in cachaça and other Brazilian surgarcane spirits, Food Chem. 149, 159– 169. https://doi.org/10.1016/j.foodchem.2013.10.088CrossrefCASPubMedWeb of Science®Google Scholar 13Santiago, W. D., Cardoso, M. G., Lunguinho, A. S., Barbosa, R. B., Cravo, F. C., Gonçalves, G. S., and Nelson, D. L. (2017) Determination of ethyl carbamate in cachaça stored in newly made oak, amburana, jatobá, balsa ans, peroba vats and in glass containers, J. Inst. Brew. 123, 572– 578. https://doi.org/10.1002/jib.463Wiley Online LibraryCASWeb of Science®Google Scholar 14Machado, A. M. d. R., Cardoso, M. d. G., Saczk, D. L., dos Anjos, J. P., Zacaroni, L. M., Dórea, H. S., and Nelson, D. L. (2013) Determination of ethyl carbamate in cachaça produced from copper stills by HPLC, Food Chem. 138, 1233– 1238. https://doi.org/10.1016/j.foodchem.2012.11.048CrossrefCASPubMedWeb of Science®Google Scholar 15Karp, J. R., Hamerski, F., and da Silva, V. R. (2017) Supported silk fibroin/poly (vinyl alcohol) membrane blends: Structure, properties and ethanol dehydration by pervaporation, Polym. Eng. Sci. . https://doi.org/10.1002/pen.24796. Web of Science®Google Scholar 16Baker, R. W., Wijmans, J. G., and Huang, Y. (2009) Permeability, permeance and selectivity: A preferred way of reporting pevaporation performance data, J. Memb. Sci. 348, 346– 352. https://doi.org/10.1016/j.memsci.2009.11.022CrossrefWeb of Science®Google Scholar 17Chen, X., Li, W., Shao, Z., Zhong, W., and Yu, T. (1999) Separation of alcohol–water mixture by pervaporation through a novel natural polymer blend membrane–chitosan/silk fibroin blend membrane, J. Appl. Pol. Sci. 73, 975– 980. Wiley Online LibraryCASWeb of Science®Google Scholar 18Feng, X., and Huang, R. Y. M. (1997) Liquid separation by membrane pervaporation: A review, Ind. Eng. Chem. Res. 36, 1048– 1066. https://doi.org/10.1021/ie960189gCrossrefCASWeb of Science®Google Scholar 19Gimenes, M. L., Liu, L., and Feng, X. (2007) Sericin/poly (vinyl alcohol) blend membranes for pervaporation separation of ethanol/water mixtures, J. Memb. Sci. 295, 71– 79. https://doi.org/10.1016/j.memsci.2007.02.036CrossrefCASWeb of Science®Google Scholar 20Rossi, S. C., Medeiros, A. B. P., Weschenfelder, T. A., Sheer, A. P., and Soccol, C. R. (2017) Use of pervaporation process for the recovery of aroma compounds produced by P. fermentans in sugarcane molasses, Bioproc. Biosyst. Eng. 40, 959– 967. https://doi.org/10.1007/s00449-017-1759-1CrossrefCASPubMedWeb of Science®Google Scholar 21Sun, D., Li, B. B., and Zu, Z. L. (2013) Pervaporation of ethanol/water mixture by organophilic nano-silica filled PDMS composite membranes, Desalination 322, 159– 166. https://doi.org/10.1016/j.desal.2013.05.008CrossrefCASWeb of Science®Google Scholar 22Alcantara, B. M., Marques, D. R., Chinellato, M. M., Marchi, L. B., Costa, S. C., and Monteiro, A. R. G. (2016) Assessment of quality and production process of a non-alcoholic stout beer using reverse osmosis, J. Inst. Brew. 122, 714– 718. https://doi.org/10.1002/jib.368Wiley Online LibraryCASWeb of Science®Google Scholar 23Gerke, I. B. B., Hamerski, F., Scheer, A. d. P., and da Silva, V. R. (2017) Clarification of crude extract of yerba mate (Ilex paraguariensis) by membrane processes: Analysis of fouling and loss of bioactive compounds, Food Bioprod. Process 102, 204– 212. https://doi.org/10.1111/j.1365-2621.2012.02965.xCrossrefCASWeb of Science®Google Scholar 24da Silva, V. R., Hamerski, F., and Scheer, A. d. P. (2012) Pretreatment of aqueous pectin solution by cross-flow microfiltration: Analysis of operational parameters, degree of concentration and pectin losses, Int. J. Food Sci. Tech. 47, 1246– 1252. https://doi.org/10.1016/j.fbp.2016.12.008Wiley Online LibraryWeb of Science®Google Scholar 25 ASTM Standard E 203-16 (2017) Standard test method for water using volumetric Karl–Fischer titration, ASTM International, West Conshocken, PA. Google Scholar 26Zhang, W., Ma, H., Wang, Q., Zhao, F., and Xiao, Z. (2012) Pretreatment technology for suspended solids and oil removal in an ethanol fermentation broth from food waste separated by pervaporation process, Desalination 293, 112– 117. https://doi.org/10.1016/j.desal.2012.03.004CrossrefCASWeb of Science®Google Scholar 27Jegatheesan, V., Phong, D. D., Shu, L., and Bein Aim, R. (2009) Performance of ceramic micro- and ultrafiltration membranes treating limed and partially clarified sugar cane juice, J. Memb. Sci. 327, 69– 77. https://doi.org/10.1016/j.memsci.2008.11.008CrossrefCASWeb of Science®Google Scholar 28Liang, B., Pan, K., Giannelis, E. P., and Cao, B. (2014) High performance hydrophilic pervaporation composite membranes for water desalination, Desalination 347, 199– 206. https://doi.org/10.1016/j.desal.2014.05.021CrossrefCASWeb of Science®Google Scholar Citing Literature Volume125, Issue32019Pages 383-388 FiguresReferencesRelatedInformation
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