https://tede.unioeste.br/handle/tede/526 2026-09-13T06:47:58Z https://tede.unioeste.br/handle/tede/8517 Title: Secagem de folhas de erva-mate (Ilex paraguariensis) por micro-ondas: avaliação dos parâmetros de cor e perfil de fitoquímicos Autor: Rota, Leonardo Henrique Primeiro orientador: Coelho, Silvia Renata Machado Abstract: This study evaluated the drying of yerba mate (Ilex paraguariensis A.St.-Hil.) leaves by microwave-assisted heating, with the aim of assessing the feasibility of microwave drying for yerba mate leaves and investigating its impact on the physicochemical quality and bioactive compound profile of the final product. Initially, fresh leaves were characterized in terms of their morphological and physicochemical properties. Drying experiments were carried out in a domestic microwave oven, operating under different combinations of power and drying time. To evaluate the experimental conditions, a Central Composite Rotatable Design (CCRD) 2² was employed, including axial points and replicates at the center point. Color parameters were determined using the CIE Lab* colorimetric system, and hue, chroma, and total color difference (ΔE) were subsequently calculated. Bioactive compounds were extracted by an aqueous method and quantified for caffeine, theobromine, and chlorogenic acid content by high performance liquid chromatography. Total phenolic compounds and antioxidant activity were also determined using the DPPH method. Using regression coefficient analysis, the effects of microwave power and drying time were evaluated on the following responses: final moisture content, color parameters, bioactive compound profile, antioxidant activity, and effective energy consumption. It was observed that increasing the applied power resulted in a significant reduction in drying time and in the final moisture content of the leaves. Significant effects of power and drying time were observed on moisture content, total phenolic compounds, antioxidant activity, and energy consumption, whereas color parameters showed smaller variations under optimized conditions when compared to conventional industrial drying. Based on the response surfaces obtained, process optimization was performed using the desirability function, allowing the identification of operating conditions capable of maximizing the preservation of bioactive compounds and minimizing energy consumption. The optimal drying condition was determined at a microwave power of 850 W and a drying time of 285 s. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação 2026-02-26T00:00:00Z https://tede.unioeste.br/handle/tede/8281 Title: Codigestão anaeróbia de esgoto sanitário, lixiviado de aterro sanitário e glicerina bruta: da seleção de proporções ao desempenho em reator de leito fixo. Autor: Pedroso, Gustavo Henrique Primeiro orientador: Gotardo, Jackeline Tatiane Abstract: Waste disposal and energy recovery has become a global priority, so landfills and Anaerobic Digestion (AD) have been frequently mentioned as options. Furthermore, AD allows biogas production, while landfills intrinsically generate leachate, an effluent difficult to be treated biologically, then, Anaerobic Co-digestion (AcoD) comes as a viable solution. Sustainability, generation volume, and composition are key-factors to be considered when selecting effluents for AcoD application. Thus, this study aimed at using Municipal Wastewater (MWW), Landfill Leachate (LL), and Crude Glycerin (CG) from biodiesel production as substrates for AcoD, evaluated in two phases. Phase 1 involved batch tests using Response Surface Methodology (RSM), while Phase 2 involved the use of a Fixed-Bed Anaerobic Reactor (FBAR) under continuous operation. Acetic and propionic acids were predominant in both phases, but the inhibition associated with propionic acid occurred due to accumulation only in Phase 1. In this phase, an optimal point of 8.584% LL, 3.376% CG, and 88.041% MWW was obtained by optimizing the response-variables: soluble COD removal (%), methane production (mL NCH4.⋅LREACTOR−1), and the Volatile Fatty Acids/Total Alkalinity (VFA/TA) ratio at the end of the experiment. Experimental validation from the optimal point in Phase 1 failed to confirm the predicted results, thereby invalidated the optimized point. However, the objective of maximizing methane production was achieved with a yield of 329.08 mL NCH4.g sCODremoved−1. This has shown that the determined ratio represents a promising mixture. In Phase 2, the mixture identified in the previous phase was evaluated in a FBAR at three different Hydraulic Retention Times (HRTs): 10, 5, and 1.9 days. Analysis of Variance (ANOVA) indicated that the optimal HRT for FBAR operation with the influent composition (8.584% LL, 3.376% CG, and 88.041% MWW) was five days. This condition achieved average total and soluble COD removal of 91%, associated with an average methane yield of 238 mL NCH4.g CODremoved−1, under stable operation (VFA/TA < 0.4). Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação 2025-11-18T00:00:00Z https://tede.unioeste.br/handle/tede/8181 Title: Codigestão anaeróbia de lixiviado de aterro sanitário com lodo flotado de agroindústria para produção de biogás Autor: Dechechi, Fernanda Gomes Primeiro orientador: Gotardo, Jackeline Tatiane Abstract: Sanitary landfill leachate, commonly known as “leachate”, exhibits high diversity and complexity in its pollutant load, making it difficult to apply a single treatment method. To prevent environmental impacts associated with its discharge into water bodies or soil, leachate must undergo complete treatment. In turn, centrifuged floated sludge, an effluent generated in agro industrial wastewater treatment, poses the challenge of being produced in large volumes, resulting in significant costs for disposal and transport to licensed facilities. Due to these characteristics, both effluents motivated the investigation of anaerobic co-digestion for biogas production, fostering the development of sustainable alternatives for treatment and clean energy generation. The objective of this study was to assess the efficiency of organic matter removal and biogas production from sanitary landfill leachate co-digested with centrifuged floated sludge from an agro-industrial complex in batch reactors, aiming at energy recovery. The research was divided into three phases: Phase 1: batch reactor using the Ritter fermentation system; Phase 2: batch reactor in BOD bottles; and Phase 3: batch reactor in a shaker. In all phases, the residues were collected and their physicochemical characteristics analyzed, as well as the mixtures of each reactor before incubation and at the end of the predetermined period. An experimental design was developed for Phases 1 and 2. Eleven reactors were incubated at 37ºC for approximately 60 days or until accumulated biogas production fell below 1%. The pH was adjusted before incubation, according to the central composite rotational design (CCRD), along with the proportions of the studied residues. Statistical analyses were applied to the results, and in Phase 2 it was possible to optimize the model. To validate the optimal point, the parameters obtained were applied to batch reactors operated on a shaker (Phase 3). Phase 1 showed that the test reactor containing centrifuged floated sludge performed better than the reactor with non-centrifuged floated sludge for the response variable (COD removal). Thus, centrifuged floated sludge was selected as the essential co-substrate for the experimental design in Phase 2. In Phase 2, among all reactors in the experimental design, Reactor 6 achieved the highest COD removal (73.73% for centrifuged COD and 84.38% for filtered COD), operating with 95% leachate and pH 7.5. For methane production, the central points of the design showed the highest values, approximately 7.5 L CH₄/L reactor, with parameters of 97.5% leachate and pH 7.5. The reactor containing only leachate (Reactor 5) and the test reactors with only centrifuged floated sludge or distilled water (Reactors 19 and 20) did not show significant results, confirming the advantage of co digestion over mono-digestion. Model optimization indicated 96.3% landfill leachate and pH 7.7 as the optimal independent variables, predicting 6.76 L CH₄/L reactor. After operating the Phase 3 reactor, methane production exceeded expectations, reaching 10.01 L CH₄/L reactor. In conclusion, the co-digestion of sanitary landfill leachate with centrifuged floated sludge from poultry processing contributes to advances in clean and renewable energy research, supporting energy autonomy through biogas production. Finally, for real-scale application, obtaining seasonal operational data from a pilot-scale reactor is recommended to generate a robust database and increase confidence in system design Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação 2025-08-25T00:00:00Z https://tede.unioeste.br/handle/tede/8120 Title: Produção de hidrogênio via lactato obtido a partir da cofermentação de água residuária de fecularia de mandioca e glicerol Autor: Baioco , Rafaela Adam Primeiro orientador: Gomes, Simone Damasceno Abstract: The rising demand for sustainable energy sources is increasing interest in the biological production of hydrogen, which is a clean and efficient alternative to traditional energy sources. This study explored the possibility of producing bioH2 using a medium rich in lactic acid as a substrate, obtained from the co-fermentation of cassava starch factory wastewater (CSW) and glycerol. The process was divided into two stages: (i) producing lactic acid-rich fermentate (FLa) in an anaerobic sequential batch reactor (ASBR) from co-fermentation of CSW and glycerol (1.5% v/v), and (ii) converting FLa to bioH2 in a continuous multi-tube reactor (CMTR). The CMTR was tested with three increasing volumetric organic loads (VOL): 48, 72, and 96 g COD L⁻¹ d⁻¹. Results showed that the lactic fermentation stage produced a uniform substrate high in lactic acid (41%) and glycerin (52%). In the CMTR, the highest volumetric hydrogen production rates (VHP = 1,960.3 mL H₂ L⁻¹ d⁻¹) and biogas flow rates (BGF = 9,360.9 mL d⁻¹) occurred with the highest VOC applied. Conversely, the highest hydrogen yield (HY = 14.1 mmol H₂ g COD⁻¹) and the greatest conversion of lactic acid (95%) and glycerol (65%) occurred at intermediate COV levels. Soluble metabolite analysis suggested the predominance of the butyric pathway in the E2 test, associated with better stability and less formation of compounds like ethanol and propionic acid that divert carbon and decrease H₂ production. Although the acetic pathway is more efficient for hydrogen generation, the butyric pathway tends to be favored in real systems due to its greater operational stability. It is concluded that combining CSW co-fermentation with glycerol and prior lactic acid production, followed by application in CMTR for H2 generation, is a promising strategy for valorizing agro-industrial waste and sustainably producing bioH2. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação 2025-08-01T00:00:00Z