The aim of this master thesis project was to develop methods for sample preparation and analysis by LC-MS suitable for global metabolomics of human plasma samples. In this thesis six different methods was tested, based on precipitation, solid phase extraction (SPE), and ultrafiltration. The methods differ in their mechanisms of action, but the end goal is the same, to remove the proteins and other high molecular weight compounds from the samples and to retain as many metabolites as possible in a reproducible manner. The LC-MS analysis were performed on a C18 and a HILIC type column using electrospray ionization (ESI) with both positive and negative ionization to cover as much of the metabolome as possible. The MarkerLynx software was then used to extract features from the chromatograms. The coefficient of variation (CV) was calculated and the features with CV > 30 % were removed. The features were then used to compare the methods with each other in order to see whether any of the methods yielded the same capture of features. The largest amount of features was detected for precipitation with MeOH when using a C18 type column. For HILIC type columns precipitation with MeOH with a small addition of H3PO4 resulted in most unique features detected. The ionization mode was found to be less important, compared whit the choice of column, but more features was detected using positive mode than negative mode.

Wastewater activated sludge is produced during the biological treatment of wastewater. After treating the sewage, the sludge is allowed to settle. Part of the settled material is returned to the treatment process as return activated sludge (RAS) and the excess is removed as waste activated sludge (WAS). The handling and disposal of the sludge are energy and capital-intensive treatments, with a significant environmental impact. This work studies the possibility to utilize RAS (an example of wastewater sludge) as a source of surface active agents. The results indicate that higly surface active materials can be extracted from RAS, and that the RAS extract has potential applications as a detergent and wood adhesive. The results also suggest that recovering a suite of products from RAS, a biological heterogenous source, can be technically feasible. An effective alkaline treatment was developed (at pH>12) that can extract up to 75% of the sludge’s organic matter, a yield higher than previously reported. Increasing the extraction pH increased the extract surface activity, which is linked to increasing the amount of higher molecular weight molecules and the presence of phospholipids. Increasing the extraction pH beyond 11 was also related to extensive cell lysis, increasing significantly the amount of recovered material and the surface activity of the extract. The alkaline extract has properties comparable to commercial detergents. Without further purification, the extract has a low surface tension (37 mN/m on average) and performs similarly to synthetic detergents. Further assessment of the RAS extract (insensitivity to pH, surface tension, interfacial tension) suggests that it may be suitable for commercial applications. The RAS extract can also be formulated into wood adhesives using glutaraldehyde as a crosslinker. The extract fraction with 10-50 kDa constituents at pH 9 achieves high adhesive shear strengths (4.5 MPa on average, at 30% relative humidity and 25°C) with 40% of wood failure. The adhesive strength of RAS-based adhesives is strongly correlated to its protein content.

Water supply systems aim, among other objectives, to protect public health by reducing the concentration of, and potentially eliminating, microorganisms pathogenic to human beings. Yet, because water supply systems are engineered systems facing variable conditions, such as raw water quality or treatment process performance, the quality of the drinking water produced also exhibits variability. The reliability of a treatment system is defined in this context as the probability of producing drinking water that complies with existing microbial quality standards. This thesis examines the concept of reliability for two physicochemical treatment technologies, conventional rapid granular filtration and ultrafiltration, used to remove the protozoan pathogen Cryptosporidium parvum from drinking water. First, fault tree analysis is used as a method of identifying technical hazards related to the operation of these two technologies and to propose ways of minimizing the probability of failure of the systems. This method is used to compile operators’ knowledge into a single logical diagram and allows the identification of important processes which require efficient monitoring and maintenance practices. Second, an existing quantitative microbial risk assessment model is extended to be used in a reliability analysis. The extended model is used to quantify the reliability of the ultrafiltration system, for which performance is based on full-scale operational data, and to compare it with the reliability of rapid granular filtration systems, for which performance is based on previously published data. This method allows for a sound comparison of the reliability of the two technologies. Several issues remain to be addressed regarding the approaches used to quantify the different input variables of the model. The approaches proposed herein can be applied to other water treatment technologies, to aid in prioritizing interventions to improve system reliability at the operational level, and to determine the data needs for further refinements of the estimates of important variables.

Techn. Universiẗat, Diss., 2003--Berlin.

L'Institut de Protection et de Sûreté Nucléaire a sélectionné le massif de Tournemire (Aveyron) pour installer sa station expérimentale dans le cadre de ses recherches sur les capacités de confinement des milieux argileux pour le stockage de déchets radioactifs. Compte tenu des très faibles teneur en eau et perméabilité des couches argileuses des argilites, la migration dans ce milieu devrait être très faible. L'écoulement et le transport ont été étudiés en utilisant des traceurs naturels de la solution interstitielle.<br />Après le développement d'un nouveau protocole pour l'extraction du chlorure de l'eau porale et des tests sur la méthode de distillation sous vide de la roche pour la mesure du deutérium de l'eau porale, l'acquisition de données pour ces deux traceurs (étudiés pour leur comportement géochimique conservatif) a été effectuée sur la séquence géologique du massif et à proximité des fractures. Les profils de données obtenus suggèrent que le processus majeur de transferts dans le massif soit la diffusion moléculaire mais ils montrent un enrichissement en deutérium et oxygène-18 de la solution interstitielle, jusqu'à un mètre à proximité des fractures, comparé à l'eau porale dans la matrice au-delà de cette zone. Ces observations suggèrent qu'un second processus de transport puisse générer des transferts spécifiques à proximité des fractures.<br />L'hypothèse du processus de diffusion moléculaire à l'échelle du massif a été testée par un modèle de transport, sur une période de plusieurs dizaines de millions d'années, en prenant en compte les caractéristiques géodynamiques de la région (telles que la tectonique et la fracturation induite), et en proposant des scénarios de variations des concentrations de traceurs aux limites du système pour représenter les changements climatiques majeurs. Les transferts de traceurs dans le massif, principalement diffusifs, sont ou ont pu être affectés par un second processus engendrant l'hétérogénéité des concentrations à proximité des fractures. Ce processus implique soit une intrusion de solutions salées, soit des transferts internes au massif dus à des surpressions.

Thesis (MScFoodSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Cyclopia genistoides (honeybush) has been identified as an excellent resource for the production of a xanthone-enriched extract due to its high mangiferin content and successful cultivation. The predominant xanthone present in C. genistoides is mangiferin, a potent antioxidant proven to exhibit a wide range of bioactivities that contribute greatly to the health-promoting abilities of honeybush extracts. Isomangiferin, the regio-isomer of mangiferin and of comparable antioxidant capacity to mangiferin, is another valuable compound present in substantial quantities in C. genistoides. A xanthone-enriched extract would find possible application in functional food/beverage products that provide health benefits beyond basic nutrition. In the current study, the effect of ethanol (EtOH) concentration (0-100%, v/v), plant material size (milled vs. teabag fraction), extraction time (0-60 min) and elevated extraction temperatures on the extraction of xanthones from unfermented C. genistoides was investigated. Single factor experiments showed the best extraction efficiency, evaluated in terms of extract yield, xanthone yield and xanthone content of the extract, was achieved by extracting milled plant material with 20-60% EtOH (v/v) for 30 min at elevated temperatures (70°C). Response surface methodology (RSM) to evaluate the individual and interaction effects of process variables, namely EtOH concentration (0-100%, v/v) and temperature (0-70°C) was used to further optimise the extraction process. EtOH concentration was found to have the largest effect on extraction efficiency (p < 0.05), whilst temperature had a negligible effect. Optimal levels of EtOH concentration (40%, v/v) and temperature (70°C) for maximum extract and mangiferin yields were successfully achieved within the experimental domain, using 10 mL/g solvent:solid ratio and 30 min extraction time. Ultrafiltration (UF) was subsequently employed to facilitate further xanthone enrichment of the unfermented C. genistoides extract (40% EtOH, v/v). A series of laboratory scale membrane devices (centrifugal membrane units, stirred cell and tangential flow ultrafiltration (TFU) system) were used in an up-scale approach to determine the effect of membrane material (regenerated cellulose (RC) vs. polyethersulphone (PES)), molecular weight cut off (MWCO; 3 kDa, 10 kDa, 30 kDa), feed concentration (1% vs. 3% soluble solids (SS)) and operating parameters (transmembrane pressure (TMP) and feed flow rate) on membrane performance and permeate quality. The best performing membrane in terms of productivity and xanthone enrichment was the 10 kDa RC membrane when using an extract concentration close to that of industrially prepared extracts (3% SS). RSM was used to further optimise UF of unfermented C. genistoides through a 10 kDa RC membrane in the TFU system. The individual and interaction effects of TMP (0.82-2.04 bar) and feed flow rate (200-444 mL/min) on permeate flux, xanthone enrichment and the fouling index were investigated. The individual effects of TMP and feed flow rate had a significant effect on all measured responses, while their interaction only affected average permeate flux and fouling index significantly. Optimal TMP and feed flow rate values of 2.04 bar and 444 mL/min, respectively, were selected within the experimental domain, restricted by equipment constraints. Validation of the combined protocol including ethanol-water extraction and UF using plant material from ten different unfermented C. genistoides batches resulted in enriched extracts containing 10.6-17.8% xanthone content. During UF, average mangiferin and isomangiferin enrichments of 20% and 22%, respectively, were obtained. Whilst no correlation was found between the feed concentration of the extracts, xanthone enrichment and fouling index, a strong linear correlation (R2 = 0.98) was found between feed concentration and permeate yield. / AFRIKAANSE OPSOMMING: Cyclopia genistoides (heuningbos) is geidentifiseer as ‘n uitstekende bron vir die produksie van ‘n xantoon-verrykte ekstrak weens sy hoë mangiferien-inhoud sowel as suksesvolle verbouing daarvan. Die oorheersende xantoon teenwoordig in C. genistoides is mangiferien, ‘n kragtige antioksidant met ‘n bewese wye reeks bioaktiwiteite wat grootliks bydra tot die gesondheidsvoordele van heuningbosekstrakte. Isomangiferien, die regio-isomeer van mangiferien met vergelykbare antioksidant-aktiwiteit as mangiferien, is nog ‘n waardevolle verbinding teenwoordig in aansienlike hoeveelhede in C. genistoides. ‘n Xantoon-verrykte ekstrak kan moontlik toegepas word in funksionele voedsel- of drankie-produkte, wat gesondheidsvoordele bo en behalwe die basiese voedsaamheid inhou. Die effek van etanol (EtOH)-konsentrasie (0-100%, v/v), plantmateriaal grootte (gemaal teenoor teesakkie-fraksie), ekstraksietyd (0-60 min) en ekstraksietemperatuur op die ekstraksie van xantone uit ongefermenteerde C. genistoides is ondersoek. Enkelfaktor eksperimente het getoon dat die beste ekstraksie-effektiwiteit, in terme van ekstrakopbrengs, xantoonopbrengs en xantooninhoud van die ekstrak, bereik is deur gemaalde plantmateriaal met 20-60% EtOH (v/v) vir 30 min by verhoogde temperature (70°C) te ekstraheer. Respons-oppervlak Metodologie (ROM) is aangewend om die individuele en interaktiewe effekte van die veranderlikes, naamlik EtOH-konsentrasie (0-100%, v/v) en temperatuur (0-70°C) te ondersoek asook om die ekstraksieproses verder te optimiseer. EtOH-konsentrasie het die grootste effek op die ekstraksie-effektiwiteit gehad (p < 0.05), terwyl die effek van temperatuur onbeduidend was. Optimale vlakke van EtOH-konsentrasie (40% v/v) en temperatuur (70°C) vir maksimum ekstrak- en mangiferienopbrengs is binne die eksperimentele domein is gevind, met die gebruik van 10 mL/g oplosmiddel:vastestof verhouding en ‘n ekstraksietyd van 30 min. Ultrafiltrasie (UF) is daarna gebruik om verdere xantoon-verryking van die ongefermenteerde C. genistoides ekstrak (40% EtOH, v/v) te fasiliteer. ‘n Reeks labratoriumskaal membraantoestelle (sentrifugale membraaneenhede, ‘n geroerde selsisteem en ‘n kruisvloei-ultrafiltrasie (KVU) sisteem) is gebruik in ‘n opskaleringsbenadering om die effek van die membraanmateriaal (geregenereerde sellulose (RS) vs. polyetersulfoon (PES)), molekulêre gewig afsnit (MWCO; 3 kDa, 10 kDa, 30 kDa), voerkonsentrasie (1% vs. 3% oplosbare vastestowwe (OV)) en operasionele parameters (transmembraandruk (TMD) en voervloeispoed) op membraanprestasie en permeaatkwaliteit te bepaal. Die membraan met die beste prestasie in terme van produktiwiteit en xantoon-verryking was die 10 kDa RS membraan wanneer gebruik met ‘n ekstrakkonsentrasie na aan dié van die industrieel vervaardigde ekstrakte (3% OV). ROM is gebruik om die KVU van ongefermenteerde C. genistoides deur ‘n 10 kDa RS membraan verder te optimiseer. Die indiwiduele en interaktiewe effekte van TMD (0.82-2.04 bar) en voervloeispoed (200-444 mL/min) op permeaatvloei, xantoon-verryking en die blokkeringindeks is ondersoek. Die individuele effekte van TMD en voervloeispoed het ‘n betekenisvolle effek op alle gemete response gehad, terwyl hul interaksie net gemiddelde permeaatvloei en besoedelingsindeks beduidend beïnvloed het. Optimale TMD en voervloeispoed waardes van 2.04 bar en 444 mL/min, onderskeidelik, is geselekteer binne die eksperimentele domein, wat bepaal is deur die beperkings van die toerusting. Die geldigheid van die gesamentlike protocol, insluitende etanol-water ekstraksie en UF, is getoets deur plantmateriaal van tien verskillende ongefermenteerde C. genistoides monsters te gebruik. Dit het gelei tot verrykte ekstrakte wat 10.6-17.8% xantone bevat het. UF het onderskeidelik gemiddelde mangiferien- en isomangiferien-verryking van 20% en 22% gelewer. Geen korrelasie is gevind tussen die voerkonsentrasie van die ekstrakte en die besoedelingsindeks nie, maar ‘n goeie liniêre korrelasie (R2 = 0.98) is tussen voerkonsentrasie en permeaatopbrengs gevind.

Novas tecnologias para o tratamento de água potável vêm sendo empregadas na medida em que a utilização de sais de alumínio tem apresentado correlação com doenças de envelhecimento mental nos seres humanos. Os coagulantes orgânicos de origem vegetal podem substituir de forma satisfatória estes sais no tratamento convencional de água potável. A utilização de processos combinados utilizando membranas de ultrafiltração com coagulação é uma alternativa aos métodos convencionais de potabilização. Com este cenário, o presente trabalho tem como objetivo comparar o desempenho operacional de uma planta piloto de ultrafiltração com membranas submersas para produção de água potável a partir do Lago Guaíba, utilizando o coagulante convencional poli (cloreto de alumínio) (PAC) e um coagulante orgânico oriundo da casca da Acácia Negra (Acacia maernsii) Tanfloc SG, com a análise da morfologia, massa molar de corte e permeabilidade hidráulica da membrana e com análises da água bruta e filtrada. As membranas de fibra oca de Poliéter Sulfona (PES) com massa molar de corte de 50 kDa, permearam sob pressão fixa de -500 mbar, com ação de borbulhamento em testes de 140 horas para avaliação da performance e testes de 10 horas para avaliação da qualidade de permeado. Os resultados indicaram semelhança no desempenho operacional dos dois coagulantes quanto à redução da permeância hidráulica relativa, e a qualidade do permeado indicou que mesmo com a ausência de flocos no tanque de alimentação, não houve passagem significativa de coagulante para o permeado. Os parâmetros de potabilidade indicaram o enquadramento da água produzida nos padrões organolépticos na atual Portaria 2914/2011 do Ministério da Saúde. / New technologies to water treatment have been applied as the aluminum salts commonly used have shown correlations with mental diseases in human beings. The organic coagulants from natural sources can satisfactorily replace those inorganic salts in drinking water treatment. The hybrid processes join ultrafiltration membranes with coagulation are alternatives to the standard potabilization. The present study compares the operational behavior of a submersed ultrafiltration (UF) pilot plant producing drinking water from Guaíba Lake, using poli (aluminum chloride) (PAC) and an organic coagulant extracted from Acacia maernsii Tanfloc SG. The membrane and the permeate were investigated. The polyether sulfone hollow fiber membranes filtered with a -500 mbar constant vacuum and air bubbles through 140 hours for performance test and for 10 hour for permeate quality verification. The results showed similarity of the relative hydraulic permeability of the two coagulants, and even with the absence of visible flocs in the membrane tank, there were no significant coagulant carryover through the membrane. The analytical data pointed that the water produced with both coagulants had concentration bellow the Brazilian organoleptic standards, according to the Portaria 2914/2011 of the Health Ministry.

O desempenho e a viabilidade econômica dos processos de separação por membranas (PSM) estão diretamente relacionados com o fluxo de permeado e a retenção de substâncias. Em escala de laboratório, onde são utilizadas pequenas áreas de permeação, pode ser observada uma elevada variabilidade dos parâmetros de desempenho dos PSM, quando comparada com a obtida para os módulos industriais. Isto pode dificultar a análise de resultados, a comparação com dados da literatura e as ações de escalonamento. Apesar dos avanços constantemente obtidos na área de membranas, os resultados obtidos para estes parâmetros ainda são susceptíveis a problemas de repetitividade e reprodutibilidade. Neste contexto, o objetivo deste trabalho foi avaliar a variabilidade experimental de membranas comerciais de ultrafiltração (UF) de polietersulfona (PES), poli(fluoreto de vinilideno) (PVDF) e poliacrilonitrila (PAN) com diferentes massas molares de corte (MMC). Os experimentos foram realizados em dois módulos de permeação com área efetiva de membrana de 28 e 60 cm2. Durante os ensaios de UF foram avaliados os seguintes parâmetros de desempenho: fluxo inicial e final de água pura, tempo de compactação da membrana, redução do fluxo (RF), permeância hidráulica antes e após a filtração da solução de polietilenoglicol (PEG), fluxo de permeado com a solução de PEG e retenção observada. A variabilidade experimental foi investigada através da identificação dos efeitos principais do processo de UF a partir da análise de variância (ANOVA). O teste F foi utilizado para identificar diferenças significativas entre as variâncias obtidas para os parâmetros de resposta determinados A partir das análises de microscopia eletrônica de varredura e de ângulo de contato observou-se que as membranas fabricadas a partir do mesmo material apresentaram estrutura e caráter hidrofílico semelhantes, não sendo observadas diferenças significativas na estrutura das membranas quando comparadas às membranas novas e às membranas após a UF. Na etapa de compactação foi observado que as membranas de mesmo material apresentaram tempo de compactação estatisticamente igual e que a RF para as membranas de PAN é semelhante. De forma geral a variabilidade experimental é menor conforme as membranas são reutilizadas no processo. Os efeitos principais de MMC e material têm influência significativa sobre os parâmetros de resposta da etapa de compactação, com exceção do efeito do material da membrana sobre o tempo de compactação e sobre a RF. Os efeitos principais de MMC, material e pressão de operação também exercem influência significativa sobre a permeância hidráulica antes e após a filtração da solução de PEG e sobre o fluxo de permeado com a solução de PEG Quando comparadas as variâncias obtidas para os parâmetros de desempenho, estas são estatisticamente semelhantes para membranas de mesmo material. Estes resultados indicam que a variabilidade experimental do processo UF (entre 10 e 40 %) não é alta o suficiente para impedir a correta identificação dos efeitos principais das variáveis do processo dentro das condições de operação avaliadas. A retenção observada foi superior a 88 % para as membranas de PES e PVDF, porém este resultado não condiz com a MMC informada pelo fabricante, uma vez que foram utilizadas soluções de PEG com massa molar menor que a MMC da membrana e a distribuição de massa molar dos PEG utilizados estão dentro da faixa especificada. Uma tendência de aumento da variabilidade dos parâmetros de resposta foi obtida quando utilizado o módulo com menor área de permeação, indicando que para as condições de área investigadas a variabilidade é aparentemente dependente da área de permeação. / The performance and the economic viability of the membrane separation processes (PSM) are directly related to permeate flux and solute retention. In laboratory scale, where small permeation areas are used, a large variability in the performance parameters of the PSM could be observed, when compared with the obtained for industrial modules. This variability may difficult analysis of the results, comparison with literature data and scale-up actions. Despite the advances that are constantly achieved in membrane technology, the results obtained experimentally for the membranes performance parameters are still prone to repeatability and reproducibility problems. In this context, the objective of this work was to evaluate the experimental variability of commercial ultrafiltration (UF) membranes of polyethersulfone (PES), polyvinylidene fluoride (PVDF) and polyacrylonitrile (PAN) with different molar mass cut-off (MMCO). The experiments were performed in a lab-scale cross-flow unit in two permeation modules with effective membrane area of 28 and 60 cm2. During the UF tests were evaluated the performance parameters: initial and final pure water flux, membrane compaction time, flux reduction (RF), hydraulic permeance before and after the filtration of the polyethylene glycol (PEG) solution, permeate flux with the PEG solution and observed retention. The experimental variability was investigated through the identification of the main effects of the UF process using the analysis of variance (ANOVA). The F-test was used to identify significant differences between the variances obtained for the response parameters determined According to the scanning electron microscopy and the water contact angle analysis, membranes made from the same material presented similar structure and hydrophilic character and were not observed significant differences in the membranes structure, when compared the new membranes with the membranes after the UF. In the compaction step it was observed that membranes of the same material presented statistically equal compaction time and the RF for the PAN membranes is similar. In general, the experimental variability is lower as the membranes are reused in the process. The main effects of MMCO and material have significant influence on the response parameters of the compaction step, the exception occur for the membrane material effect on the compaction time and RF. The main effects of MMCO, material and transmembrane pressure also exert significant influence on the hydraulic permeance before and after the PEG filtration and on the permeate flux with the PEG solution. When comparing the variances obtained for the performance parameters, they are statistically similar for membranes of the same material These results indicate that the experimental variability of the UF process (between 10 and 40%) was not high enough to prevent the correct identification of the effects of the main process variables within the evaluated operation conditions. The observed retention was greater than 88 % for the PES and PVDF membranes, but this result is not consistent with the MMCO reported by the manufacturer, since PEG solutions with lower molar mass than membrane MMCO were used and the molar mass distribution of the PEGs are within the specified range. A tendency to increase the experimental variability of the response parameters was observed when using the modulus with lower permeation area, indicating that for the range of effective membrane area investigated the variability is apparently dependent of the permeation area.

Os processos de separação com membranas estão presentes nas mais diversas aplicações industriais. Em especial, a microfiltração e a ultrafiltração vêm sendo extensivamente utilizadas no tratamento de água e de efluentes. Com o aumento da demanda, muitos estudos têm sido feitos para melhorar o desempenho dos processos com membranas, porém a escolha apropriada da membrana é um fator crucial para atingir esse objetivo. As membranas à base de polietersulfona (PES) estão entre as mais utilizadas industrialmente para esse tipo de aplicação devido às suas excelentes propriedades mecânicas, estabilidade térmica e resistência química. No entanto, por serem pouco hidrofílicas, essas membranas apresentam baixos fluxos de água e elevada tendência ao fouling e ao biofouling. A fim de melhorar essas propriedades, muitos autores têm proposto modificações nas membranas para torná-las mais hidrofílicas e, portanto, aumentar o fluxo de água e diminuir o fouling. Dentro desse contexto, o presente trabalho teve como objetivo preparar membranas de ultrafiltração de PES, utilizando a ftaloil-quitosana (FQ) como aditivo, a fim de se obter membranas com propriedade antifouling. Membranas de PES e PES/FQ foram preparadas pelo processo de inversão de fases e caracterizadas quanto à morfologia, à estrutura química, à estabilidade térmica, ao caráter hidrofílico, à permeância hidráulica, à massa molar de corte (MMC) e ao desempenho em ultrafiltração de solução proteica. As membranas modificadas com o aditivo apresentaram estrutura mais heterogênea e com macrovazios maiores, maior caráter hidrofílico e maior permeância hidráulica. Os resultados de MMC não foram conclusivos. No teste de ultrafiltração, essas membranas apresentaram maiores fluxos e menor tendência ao fouling, indicando que o aditivo utilizado foi adequado na melhoria das propriedades desejadas. A retenção proteica, a perda de fluxo e a recuperação de fluxo após limpezas não apresentaram diferenças significativas. / In recent years, membrane separation processes have been widely used in all kinds of industries and applications. Particularly microfiltration and ultrafiltration have been extensively used for drinking water and wastewater treatments. With the increasing demand, many efforts have been done in order to enhance the process performance, but the choice of the appropriate membrane is a crucial factor to achieve this goal. Polyethersulfone (PES) based membranes are among the most commonly used for such applications due to their excellent chemical resistance, thermal stability and mechanical properties. However, because of its low hydrophilicity, these membranes have low water flux and high fouling and biofouling tendency. In order to improve these properties, many authors have proposed membrane modifications to make them more hydrophilic and thus increase the water flux and reduce fouling. Within this context, this work aimed to prepare PES ultrafiltration membranes using phthaloyl-chitosan (FQ) as an additive in order to obtain membranes with antifouling property. PES and PES/FQ membranes were prepared by phase inversion process and their morphology, chemical structure, thermal stability, hydrophilicity, hydraulic permeance, molecular weight cutoff (MWCO) and performance in ultrafiltration of protein solution were characterized. The membranes modified with additives showed more heterogeneous structure with larger macrovoids, higher hydrophilicity and higher hydraulic permeance. The MWCO results were inconclusive. In the ultrafiltration test, these membranes exhibited higher fluxes and lower fouling tendency, indicating that the additive used was adequate in improving the desired properties. The protein retention, flux reduction and flux recovery after cleaning showed no significant differences.

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