Orientador: Luiz Antonio Viotto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-16T15:09:54Z (GMT). No. of bitstreams: 1 Aragao_VitorCardoso_M.pdf: 24667978 bytes, checksum: b244b99f0ba81a272f7b8a6fc720e5d1 (MD5) Previous issue date: 2010 / Mestrado / Mestre em Engenharia de Alimentos

Neste trabalho avaliou-se a eficácia de dois sistemas sequenciais de tratamento de esgoto sanitário envolvendo processo biológico anaeróbio (em escala piloto) com processos físico-químicos de flotação (escala de laboratório), microfiltração tangencial (escala industrial) e osmose reversa (escala industrial). Foram realizadas cinco baterias de ensaios (primeira etapa de estudos) utilizando um sistema seqüencial composto por: reator anaeróbio biológico, flotação por ar dissolvido, filtração em areia, filtração em cartucho de 5 &#956m, filtração em papel de filtro de 1,2 &#956m/filtração em cerâmica microporosa e filtração em membrana de nanofiltração. Numa segunda etapa de estudos foi realizada uma bateria de ensaios utilizando um sistema seqüencial composto por: reator anaeróbio biológico, flotação por ar dissolvido, microfiltração tangencial e osmose reversa. Todos os efluentes gerados pelos dois sistemas de tratamento foram avaliados, e a possibilidade de reuso (agrícola e industrial) dos mesmos foi investigada, os efluentes da filtração em areia, filtração em cartucho, filtração de papel de filtro/filtração em cerâmica e nanofiltração (primeira etapa de estudos) apresentaram características compatíveis com a água necessária para a maioria dos processos industriais. Por outro lado, os efluentes da microfiltração tangencial e da osmose reversa (segunda etapa de estudos) se mostraram como uma boa alternativa para reuso agrícola e também para reuso industrial(principalmente o efluente da osmose reversa). / This work evaluates the efficiency of two sequence systems of treatment of sewage involving anaerobic biologycal and physical-chemical processes. Five sets of experiments were done in the first stage of the study, using a sequence system formed with: anaerobic biologycal reactor, dissolved - air flotation, sand filtration, cartridge filtration (5 &#956m), filter paper filtration (1,2 &#956m)/ceramic filtration and nanofiltration. Another set of experiments was carried out using a different sequence system formed with: anaerobic biologycal reactor, dissolvid-air flotation, crossflow microfiltration and reverse osmosis. Every effluent resulted from the two treatment systems was evaluated and the reuse possibility (agricultural and industrial) was invetigated. The sand filtration, cartridge filtration, filter paper filtration/ceramic filtration and nanofiltration effluents (of the first step of studies) showed compatible characteristics with irrigation water but they were not compatible with water used in the majority industrial processes. On the other hand the crossflow microfiltration and reverse osmosis effluents (of the second step of studies) can be said as a good alternative to agricultural reuse and industrial reuse as well (mainly the reverse osmosis effluent).

M.Tech. (Chemistry) / This work focused on the in-situ decoration of polyethersulfone (PES) nanofiber mats with silver nanoparticles (AgNPs) using an electrospinning technique. The biocidal and organic properties of the Ag decorated nanofibers were evaluated. Electrospinning of Ag decorated nanofibers was also carried out on a mixed matrix membrane support composed of nitrogen doped carbon nanotube (N-CNTs) and PES to fabricate a unique bi-faceted membrane. PES was dissolved in a solution containing silver nitrate (AgNO3) and N,Ndimethylacetamide (DMAc). The polymer solution was dissolved at 80ºC for 3 h under reflux until a yellow homogeneous solution was obtained which indicated the in-situ formation of AgNPs. The polymer solution was cooled and stored to remove air-bubbles. An ultraviolet - visible (UV – Vis) spectrometer was used to confirm the presence of AgNPs, while a Malvern nanosizer was used to estimate the size distribution of the AgNPs in the PES polymer matrix. The solution was electrospun on an aluminium (foil) collecting plate. Biocidal properties of the material were evaluated using Gram-positive (G+) Staphylococcus aureus (S. aureus) and ram-negative (G-) Escherichia coli (E. coli) by the zone inhibition method. The silver decorated polyethersulfone nanofibers showed good antibacterial activity against both G+ S. aureus and G- E. coli.

No description available.

MSc. (Applied Chemistry) / Remediation of POPs particularly the chlorinated compounds in water is therefore crucial. This research work describes the modification of polyethersulfone (PES) thin-film membrane composite (TFC) with functionalised carbon nanotubes (f-CNTs) using the phase invasion method. The oxidised CNTs were successfully decorated with Zero-Valent (ZV) Fe/Ni nanoparticles for the adsorption and degradation studies of polychlorinated organic pollutants (in this case the dichlorodiphenyltrichloroethanes (DDTs)). The in situ modification procedure was carried out using different quantities (0.04 wt%, 0.1 wt% and 0.2 wt%) of Fe/Ni-f-CNTs nanohybrids dispersed in a DMAc solution and dipping the polyethersulfone powder into a suspension containing the Fe/Ni-f-CNTs to form a nano-composite membrane. The formed composite membrane characteristics were investigated with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle (CA) and X-ray diffraction spectroscopy (XRD). The incorporation of nanohybrid in the PES membrane was found to increase the surface smoothness and the hydrophilicity of the composites. In addition, there was an increase in the adsorption of DDTs with increase in the nano-hybrid loading as indicated by the adsorption studies using the Langmuir isotherm and Freundlich isotherm studies. The data obtained from the batch studies closely fitted with the Langmuir isotherm based on the characteristic parameter RL found to lie within the standard range 0 < RL < 1 .

Maintenance of membrane performance requires inevitable cleaning or defouling of fouled membranes. Membrane cleaning using enzymes such as proteases, lipases, α-glucosidases from a sulphidogenic bioreactor was investigated. At first, dilute and concentrated enzyme extract were prepared form the sulphidogenic pellet. Enzyme assays on 0.5 % azocaisen, 1 % triacetin and 1 mg/ml ρ-nitrophenyl-α-D-glucopyranoside were performed using the concentrated enzyme extract (0 – 200 mg/ml). For membrane fouling, an abattoir effluent was obtained from Ostritech Pty (Ltd), Grahamstown, South Africa. The effluent was characterised for presence of potential foulants such as lipids, proteins, amino acids and carbohydrates. Static fouling of polysulphone membranes (0.22 μm, 47 mm) was then performed using the abattoir effluent. Cleaning of the fouled membranes was also performed using at first the dilute and then the concentrated form (200 mg/ml) of enzyme extracts. Qualitative and quantitative biochemical analysis for proteins, lipids and carbohydrates was performed to ascertain the presence of foulants on polysulphone membranes and their removal by dilute or concentrated enzyme extracts. The ability of dilute enzyme extracts to remove proteins lipids, and carbohydrates fouling capillary UF membrane module; their ability to restore permeate fluxes and transmembrane pressure after cleaning/defouling was also investigated. Permeate volumes from this UF membrane module were analysed for protein, amino acids, lipids, and carbohydrates concentrations after fouling and defouling. Fouling was further characterized by standard blocking, cake filtration and pore blocking models using stirred UF cell and polyethersulphone membranes with MWCO of 30 000, 100 000 and 300 000. After characterization of fouling, polyethersulphone membranes with MWCO of 30 000 and 300 000 were defouled using the concentrated enzyme extract (100 mg ml). Enzyme activities at 200 mg/ml of enzyme concentration were 8.071 IU, 86.71 IU and 789.02 IU for proteases, lipases and α-glucosidases. The abattoir effluent contained 553 μg/ml of lipid, 301 μg/ml of protein, 141 μg/ml of total carbohydrate, and 0.63 μg/ml of total reducing sugars. Proteins, lipids and carbohydrates fouling polysulphone membranes after a day were removed by 23.4 %, when a dilute enzyme was used. A concentrated enzyme extract of 200 mg/ml was able to remove proteins, lipids and carbohydrates up to 5 days of fouling by 100 %, 82 %, 71 %, 68 % and 76 % respectively. Defouling of dynamically fouled capillary ultrafiltration membranes using sulphidogenic proteases was successful at pH 10, 37°C, within 1 hour. Sulphidogenic proteases activity was 2.1 U/ml and flux Recovery (FR %) was 64. Characterization of fouling revealed that proteins and lipids were major foulants while low concentration of carbohydrates fouled polyethersulphone membranes. Fouling followed standard blocking for 10 minutes in all the membranes; afterwards fouling adopted cake filtration model for membranes with 30 000 MWCO and pore blocking model for membranes with 300 000 MWCO. A concentration of 100 mg/ml of enzyme extract was able to remove fouling from membranes with MWCO of 30 000. Defouling membranes that followed pore blocking model i.e. 300 000 MWCO was not successful due to a mass transfer problem. From the results of defouling of 30 000 and 300 000 MWCO it was concluded that defouling of cake layer fouling (30 000 MWCO) was successful while defouling of pore blocking fouling was unsuccessful due to a mass transfer problem. The ratio of enzymes present in the enzyme extract when calculated based on enzymatic activity for proteases, lipases and α-glucosidases was 1.1 %, 11 % and 87.9 %. It was hypothesized that apart from proteases, lipases, α and β-glucosidases; phosphatases, sulphatases, amonipeptidases etc. from a sulphidogenic bioreactor clean or defoul cake layer fouling by organic foulants and pore blocking fouling provided the mass transfer problem is solved. However, concentration of enzymes from a sulphidogenic bioreactor has not been optimized yet. Other methods of concentrating the enzyme extract can be investigated for example use of organic solvents.

Gravity-driven membrane (GDM) filtration is one of the promising membrane bioreactor (MBR) technologies. It operates at a low pressure by gravity, requiring a minimal energy. Thus, it exhibits a great potential for a decentralized system, conducting household in developing and transition countries. Biofouling is a universal problem in almost all membrane filtration applications, leading to the decrease in flux or the increase in transmembrane pressure depending on different operation mode. Air scoring or regular membrane cleaning has been utilized for fouling mitigation, which requires increased energy consumption as well as complicated operations. Besides, repeating cleaning will trigger the deterioration of membranes and shorten their lifetime, elevating cost expenditures accordingly. In this way, GDM filtration stands out from conventional MBR technologies in a long-term operation with relative stable flux, which has been observed in many studies. The objective of this study was to monitor the biofilm development on a flat sheet membrane submerged in a GDM reactor with constant gravitational pressure. Morphology of biofilm layer in a fixed position was acquired by an in-situ and on-line OCT (optical coherence tomography) scanning at regular intervals for both visual investigation and structure analysis. The calculated thickness and roughness were compared to the variation of flux, fouling resistance and permeate quality, showing expected consistency. At the end of experiment, the morphology of entire membrane surface was scanned and recorded by OCT. Membrane autopsy was carried out for biofilm composition analysis by total organic carbon (TOC) and liquid chromatography with organic carbon detection (LC-OCD). In addition, biomass concentration was obtained by flow cytometer and adenosine tri-phosphate (ATP) method. The data of biofilm components indicated a homogeneous biofilm structure formed after a long-term running of the GDM system, based on the morphology observation by OCT images. The superiority of GDM in both flux maintaining and long-term operation with production of high quality effluent was demonstrated, as well as the suitability of OCT for biofouling monitoring was emphasized.

No description available.

Aevitas is an industrial wastewater treatment plant that receives about 300 m3/day of mixture of wastewater from different industries. The chemical oxygen demand of higher 600 ppm and the variety of the chemical constitution of industrial wastewater are two significant problems on Aevitas. Therefore, there is a strong need for developing advanced analytical techniques that can identify the specific compounds that are the source of COD. During 10 months, about 75 industrial samples were characterized using a battery of tests including GC/MS, COD, TOC, and pH to identify the chemicals that are main source of COD in the industrial wastewaters. Results showed that the COD of 87% of 75 provided samples from Aevitas plant was higher than 600. At the first step of process design, activated carbon was used to eliminate the identified organic chemicals from the wastewaters. The maximum and minimum of COD removal (depends on the chemical composition) of the wastewaters were obtained as 94 and 24%, respectively. Moreover, the amount of COD and TOC that can be adsorbed on the surface of 1 gram of the activated carbon were 25 and 7 mg, respectively. Although activated carbon is capable to reduce the COD, its capacity of adsorption is limited. To overcome this problem an alternative process, membrane filtration was applied for COD removal. Two types of crossflow NF (NF270, NF90, NFX, NFW, NFS, TS80, XN45, and SXN2_L) and RO (BW60 and TW30) membranes in two modules of the spiral wound and flat sheet were used. The filtration results of 11 different industrial wastewaters showed that NF90, TS80, NFX, and NFS were effective in COD removal. However, in terms of output flux NFX and NFS flat sheet were better than others were. Similar to the activated carbon process, the COD removal in filtration process was between 30 and 90%. The obtained results can be used to scale up the membrane filtration process at Aevitas. / Thesis / Master of Chemical Engineering (MChE) / Aevitas is an industrial wastewater treatment plant, which is situated at the City of Brantford. Every day, this plant receives about 15 trucks of the mixture of wastewaters from many different industries. The input wastewater into the plant should be treated and meet the environmental standard so that it can be discharged into a municipal wastewater plant. Currently, the maximum allowable chemical oxygen demand (COD) for discharging the treated wastewater from Aevitas to the municipal wastewater treatment plant is 600 ppm. Despite the fact, the current system in Aevitas is not efficient to meet this criterion. Thus, we strive to design efficient processes to overcome the problem. To this end, 75 samples were collected from Aevitas to observe the kind of chemicals that are the source of COD and then, two processes including activated carbon adsorption and membrane filtration were used for further reduction of COD. Although activated carbon can reduce the COD, the limited adsorption capacity was a major concern for its long-term application, especially if the COD of influent wastewater is higher than 2000 ppm. Membrane filtration was used as an alternative for activated carbon and the results showed that membrane could reduce the COD below 600 in 48% of the cases.

Wastewaters that are produced by industrial processes are more challenging to treat than municipal wastewaters, primarily due to two reasons. Firstly, industrial wastewaters contain high concentrations of several different contaminants (e.g. metals, nutrients and organics etc.), which can be challenging for a single process to treat. Secondly, the compositional properties of the wastewaters can vary significantly as it is dependent on several upstream processes. Commercial membrane technologies have shown significant adoption in desalination and municipal wastewater treatment applications. Their favourable selectivity and tunable properties have garnered interest from both academia and industry to push these technologies into industrial wastewater treatment. Despite showing promising contaminant removal results, current studies have shown that fouling due to high contaminant loadings, and variable treatment efficacies due to feed property variations, limit the adoption of commercial membranes into these applications. Current research addresses these challenges through the new material development or surface modifications, however, there is a need to approach these challenges at a process level by integrating existing membrane technology into adaptive processes. This thesis aims to advance the adoption of commercial membrane technology into ‘tough-to-treat’ industrial wastewater applications. Firstly, the effects of high contaminant concentrations and variable feed properties on membrane treatment is studied by using advanced techniques, such as gas chromatography – mass spectrometry, to resolve the composition of feed and permeate streams from membrane processes treating real wastewaters. It was determined that fast and efficient screening tools are required to optimize and adapt membrane processes to respond to this variability. This thesis then introduces high-throughput and miniaturized screening platform that combines analytical centrifugation with filter plate technology to rapidly optimize two-stage coagulation-filtration processes with an extremely low material and time requirement. / Thesis / Doctor of Philosophy (PhD) / Wastewaters sourced from industrial processes are considered ‘tough-to-treat’ due to high contaminant concentrations and time-varying compositional properties. Recent advancements in membrane technologies have demonstrate great promise in treating industrial wastewaters, however, these membranes often need to be integrated with other treatment technologies to overcome challenges with treating these wastewaters. This thesis aims to push the adoption of integrated membrane processes for treating high-strength industrial wastewaters. By utilizing advanced analytical techniques to investigate the effects of high contaminant loadings and variable feed properties on membrane processes, it was determined that screening tools are needed to rapidly design and optimize membrane process that are tailored to the properties of the wastewater. This thesis introduces a high-throughput and miniaturized screening platform that combines analytical centrifugation and filter-plate technology to holistically screen two-stage coagulation-filtration processes with little time and material requirements.