DSpace Coleção:https://repositorio.ufpb.br/jspui/handle/123456789/24032026-04-13T16:01:36Z2026-04-13T16:01:36ZDesenvolvimento de um método voltamétrico automatizado em sistema fluxo batelada para a determinação de naftalenoAlves, Lucas Isidiohttps://repositorio.ufpb.br/jspui/handle/123456789/376502026-02-20T06:07:49Z2026-02-09T00:00:00ZTítulo: Desenvolvimento de um método voltamétrico automatizado em sistema fluxo batelada para a determinação de naftaleno
Autor(es): Alves, Lucas Isidio
Orientador: Nunes, Tassio de Araújo
Abstract: Polycyclic aromatic hydrocarbons (PAHs) represent an environmental and public health
problem, as these compounds are recognized for their high toxic, mutagenic, and carcinogenic
potential. Among them, naphthalene (NAF) stands out due to its high frequency of occurrence
in water bodies and its association with adverse health effects. Therefore, this work aimed to
develop an automated voltammetric method in a flow-batch analysis (FBA) system for the
determination of NAF, seeking greater precision, reproducibility, and sensitivity compared to
traditional methods, which consist of manual addition of solutions via pipetting. The proposed
automated system has a mixing chamber made of polytetrafluoroethylene (PTFE), a peristaltic
pump, solenoid valves, and a program written in LabView® was developed for its management,
allowing the automation of steps such as electrochemical treatment of the working electrode,
addition, and disposal of solutions. A boron-doped diamond electrode (BDDE) was used as the
working electrode, and square wave voltammetry (SWV) was chosen as the analytical
technique due to its high sensitivity and speed of analysis. Preliminary studies showed that pH
influences the electrochemical response of the analyte, with pH 10 of the Britton-Robinson
(BR) buffer being the optimal condition for analysis. NAF exhibited irreversible redox
behavior, with the mass transfer process governed by diffusion. Optimization of the
experimental parameters resulted in the following ideal conditions: frequency of 50 Hz,
amplitude of 5 mV, and increment of 7 mV. Under these conditions, no memory effect was
observed in the electrode, ensuring good reproducibility of the results. After optimization of the
voltammetric parameters, analytical curves of the traditional method and the proposed system
were obtained for comparison of the two methods. The analytical curves showed adequate
linearity (R2 = 0.9886 for the traditional method and R2 = 0.9954 for the FBA system). The
detection and quantification limits obtained were 4.17 × 10−8 mol·L−1 and 1.26 × 10−7 mol·L−1,
respectively, for the benchtop method, and 1.52 × 10−8 mol·L−1 and 4.60 × 10−8 mol·L−1 for the
FBA, indicating a significant improvement in terms of sensitivity, reproducibility, and data
acquisition speed when applying voltammetric FBA. The proposed method shows great
potential for application in environmental analyses as a future prospect, providing an efficient
and automated alternative for monitoring contaminants in drinking water.
Editor: Universidade Federal da Paraíba
Tipo: TCC2026-02-09T00:00:00ZCinética de crescimento de leveduras nativas em diferentes fontes de carbono e temperaturaLemos, Gabriel Jacomini Rochahttps://repositorio.ufpb.br/jspui/handle/123456789/366972025-12-02T06:10:00Z2025-10-17T00:00:00ZTítulo: Cinética de crescimento de leveduras nativas em diferentes fontes de carbono e temperatura
Autor(es): Lemos, Gabriel Jacomini Rocha
Orientador: Santos, Sharline Florentino de Melo
Abstract: This study aimed to analyze the growth kinetics of native yeast strains isolated from
sugarcane cultivated in the region of Areia, Paraíba (Brazil), with a view to their application
in alcoholic fermentation processes. Three strains (2506S, 2754S, and 3129I) were selected
for evaluation under different cultivation conditions, using three carbon sources (sucrose,
glucose, and maltose) and three temperature ranges (15 °C, 30 °C, and 37 °C). The
experiments were conducted in an orbital shaker under controlled temperature, according to
the parameters established for the pre-inocula. After the growth period, the cultures were
standardized to a concentration of 10⁸ CFU/mL and distributed into 96-well microplates,
maintained under the same temperature conditions. Readings were performed using an
ELISA-type microplate reader every two hours during the first 12 hours of cultivation, and
subsequently every 12 hours. The analyses were conducted by determining cell growth
curves, the maximum specific growth rate (𝜇𝑚𝑎𝑥), and the generation time (𝑡𝑔). The results
showed that strain 2506S exhibited the best performance at 15 °C and 30 °C, with high
𝜇𝑚𝑎𝑥values and short generation times, indicating strong growth potential under these
conditions. In contrast, elevated temperatures (37 °C) resulted in reduced performance for
strains 2506S and 2754S, suggesting thermal sensitivity. Strain 3129I, in turn, showed more
stable behavior across all tested temperatures and carbon sources. These findings are
consistent with the literature, which indicates 30 °C as the optimal range for the growth of
Saccharomyces cerevisiae, with decreased cellular activity at supra-optimal temperatures.
The thermal and nutritional stability of strain 3129I highlights its potential for industrial use
in processes subject to operational variability. Additionally, the high cell concentration
reached by strain 2506S at 15 °C at the end of the exponential phase suggests its feasibility
for fermentative processes at lower temperatures. These findings reinforce the importance of
prospecting native microorganisms as a strategy for developing more efficient, robust, and
regionally adapted fermentations.
Editor: Universidade Federal da Paraíba
Tipo: TCC2025-10-17T00:00:00ZEstudo da Atividade amilolítica de extrato enzimático de trichoderma reesei na hidrólise da casca do cará (Dioscorea alata)Dreher, Ralael Santoshttps://repositorio.ufpb.br/jspui/handle/123456789/345512025-05-29T06:15:59Z2025-05-06T00:00:00ZTítulo: Estudo da Atividade amilolítica de extrato enzimático de trichoderma reesei na hidrólise da casca do cará (Dioscorea alata)
Autor(es): Dreher, Ralael Santos
Orientador: Sousa, Carlos Alberto Bispo de
Abstract: This study aimed to evaluate the application of the enzymatic extract produced by the fungus
Trichoderma reesei in converting yam peel biomass into fermentable sugars. Amylase
production was carried out through solid-state fermentation (SSF), using a substrate
composed of corn cob and wheat bran. The microorganism was incubated on the moistened
substrate for seven days, and the crude enzymatic extract was obtained using sodium citrate
buffer. Amylolytic activity was determined by quantifying reducing sugars through the
dinitrosalicylic acid (DNS) method. A 2² factorial design was applied to assess the effects of
pH and temperature on enzymatic activity, with pH showing the most significant influence
under the tested conditions. The best combination (pH 4,8 and 50 °C) was used to perform
the enzymatic hydrolysis of yam peel biomass, monitoring the release of reducing sugars over
time. The results demonstrated the feasibility of the process, with a gradual increase in sugar
concentration and high productivity in the initial minutes. It is concluded that the enzymatic
extract produced via SSF is a promising and low-cost alternative for converting
agro-industrial residues into value-added compounds, such as fermentable sugars, with
potential application in second-generation bioethanol production.
Editor: Universidade Federal da Paraíba
Tipo: TCC2025-05-06T00:00:00ZDegradação de diuron por processos oxidativos avançados: O3, O3/Uv-C E Uv-CSantos, Ester Ribeiro da Luzhttps://repositorio.ufpb.br/jspui/handle/123456789/341012025-03-28T06:20:21Z2024-11-05T00:00:00ZTítulo: Degradação de diuron por processos oxidativos avançados: O3, O3/Uv-C E Uv-C
Autor(es): Santos, Ester Ribeiro da Luz
Orientador: Madeira, Vivian Stumpf
Abstract: The herbicide Diuron, widely used for weed control in agriculture, stands out among emerging
contaminants due to its environmental persistence and potential toxicity. Frequently detected in
water bodies, this herbicide poses a considerable risk to human health and aquatic ecosystems,
exacerbated by its resistance to conventional degradation processes. This study investigated
alternatives for Diuron degradation using Advanced Oxidative Processes (AOPs), focusing on
ozonation (O₃), ozonation with UV-C radiation (O₃/UV-C), and isolated UV-C radiation (UVC). The methodology included tests in a photoreactor, where variables such as pH, initial
Diuron concentration, and reaction time were controlled to assess the efficiency of each process,
including the evaluation of reaction kinetics. Results indicated that the O₃/UV-C system was
particularly effective at pH 9, with an initial contaminant concentration of 5 mg/L achieving
96% degradation and predominantly exhibiting first-order degradation kinetics, with a rate
constant of 0.039 in optimal conditions. This study highlights the potential of the O₃/UV-C
system for treating herbicide-contaminated waters and underscores the need for further research
to evaluate by-products and the feasibility of scaling up the process
Editor: Universidade Federal da Paraíba
Tipo: TCC2024-11-05T00:00:00Z