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Avaliação ecotoxicológica do Bisfenol a e sua remoção em água utilizando a biomassa ativada de Ingá-cipó (Inga edulis)

2025-11-05T00:00:00Z

Título: Avaliação ecotoxicológica do Bisfenol a e sua remoção em água utilizando a biomassa ativada de Ingá-cipó (Inga edulis) Autor(es): Lima, Lidivania Barbosa Abstract: Bisphenol A (BPA) is a substance used in the production of plastics and resins and is recognized for causing harmful effects on the environment and human health. As an endocrine disruptor, BPA can cause hormonal alterations, reproductive problems, and impacts on the growth and metabolism of aquatic organisms and humans. In this context, the search for effective strategies that enable its removal represents a current challenge. In this study, the toxicity of BPA to freshwater organisms was investigated before and after the application of adsorption techniques, using activated biomass from Inga edulis bark as the adsorbent material. Acute toxicity assays were conducted with Daphnia similis and Ceriodaphnia silvestrii to determine CE50 values (24 and 48 h), and with Chironomus sancticaroli to determine the CL50 (96 h). The mean CE50 values (24 and 48 h) for D. similis were 10.50 and 8.89 mg L⁻¹, respectively; for C. silvestrii, they were 5.64 and 3.63 mg L⁻¹, respectively; while for C. sancticaroli, the CL50 (96 h) was 3.32 mg L⁻¹. After determining the CE50 and CL50 values for BPA, the optimization of adsorption parameters was carried out, including kinetics, pH, isotherms, and optimal dosage. The biomass was previously characterized using SEM, FTIR, TG, CHN, BET, XPS, and point of zero charge (PZC) analyses, which confirmed structural modifications and the presence of functional groups relevant to the activation and adsorption processes. The adsorption assays demonstrated a significant reduction in BPA concentration in the samples, with removal efficiencies ranging from 38% to 61%. In addition, BPA concentrations before and after the adsorption process were quantified by electrochemical techniques and UV–Vis spectrophotometry. When the treated samples were re-exposed to the test organisms, survival rates of 100% for D. similis at 24 h and 80% at 48 h, 100% for C. silvestrii at both exposure periods (24 and 48 h), and 98% for C. sancticaroli at 96 h were observed, evidencing a substantial reduction in BPA toxicity after treatment. The results indicate that activated I. edulis bark biomass has high potential as an ecological and efficient adsorbent material, capable of significantly reducing BPA concentration and toxicity in aquatic environments, thus contributing to the development of sustainable alternatives for the treatment of contaminated waters.

Indicadores de sustentabilidade para avaliação da coleta seletiva de resíduos sólidos urbanos em Aracaju-Se

2024-04-12T00:00:00Z

Título: Indicadores de sustentabilidade para avaliação da coleta seletiva de resíduos sólidos urbanos em Aracaju-Se Autor(es): Costa, Rodolfo Oliveira Abstract: The area of solid waste management is of vital importance to any city. In the city of Aracaju/SE, this is no different and this research aimed to contribute in the sense of proposing the use of sustainability indicators, selected with correlation to selective collection and within the environmental, economic, institutional/operational and socio-cultural dimensions, and thus evaluate the system of selective collection of urban solid waste in the city by means of a sustainability matrix. Alongside this research, a gravimetric study of municipal solid waste was also carried out. The methodology employed was based on a descriptive, exploratory, qualitative, and quantitative study format, with a specific bibliographic survey, as well as observations, records and data collection. The results obtained from the gravimetric study showed the potential for developing work aimed at composting waste, as well as the need to expand environmental education throughout the city, specifically with selective collection. As for the level of sustainability, its final score was enough to classify the system as medium sustainability (NS = 5.20), where the order of performance of the dimensions in the matrix found was: economic < environmental < institutional/operational < socio-cultural. It is therefore believed that the municipality's administrators should pay attention to the indicators proposed in this study, to improve their weak points (economic dimension) and enhance their strong points (socio-cultural dimension), and thus achieve continued improvements in solid waste management.

Modelagem e simulação termodinâmica para estimativa da energia mínima de regeneração de MDEA saturada no refino de petróleo

2025-10-13T00:00:00Z

Título: Modelagem e simulação termodinâmica para estimativa da energia mínima de regeneração de MDEA saturada no refino de petróleo Autor(es): Vieira, Lucas Paixão Abstract: The regeneration of aqueous solutions of methyldiethanolamine (MDEA) saturated with acid gases such as CO₂ and H₂S represents a significant energy and environmental challenge in petroleum refining. This work estimates the theoretical minimum energy required for this process, in alignment with the principles of energy efficiency and sustainability. Thermodynamic modeling was based mainly on the Electrolyte NonRandom Two-Liquid (eNRTL) model, used to calculate activity coefficients, equilibrium constants, and Gibbs free energy variations (ΔG) in an aqueous MDEA–H₂O–CO₂–H₂S system at temperatures between 393 K and 403 K. The computational implementation in Python enabled the simulation of chemical equilibrium between the initial (saturated) and final (regenerated) states, considering dissociation reactions and ionic interactions. Results indicated a minimum energy of 207.8 kJ to regenerate 100 mol of solution, equivalent to 806.95 kJ/kg of CO₂ removed, corresponding to approximately 6.45% of the actual energy consumption reported in industrial processes (12,500 kJ/kg of CO₂). Sensitivity analyses showed that ΔG_total decreases with higher acid gas loading and elevated temperatures, reaching a maximum at MDEA mole fractions around 0.5. From an economic perspective, the minimum regeneration cost was estimated at R$ 190.53/tCO₂, considering an electricity tariff of R$ 0.85/kWh in Northeastern Brazil, while the actual cost based on reboiler energy consumption reached R$ 2,951.39/tCO₂ — a competitive value in global carbon markets (such as the EU ETS, at around R$ 410/tCO₂). Regeneration proved far more advantageous than replacing MDEA with fresh solvent (R$ 24,000–48,000/tCO₂) and showed potential for reuse of the exhausted MDEA in CO₂ capture from air or flue gases, generating higher-value credits (US$ 170– 500/tCO₂). The findings contribute to the optimization of industrial processes, emission reduction, and alignment with the Sustainable Development Goals, while suggesting future integration with kinetic models, life-cycle assessments, and hybrid regeneration technologies.

Degradação da tetraciclina em efluentes de carcinicultura por eletro-oxidação

2025-08-28T00:00:00Z

Título: Degradação da tetraciclina em efluentes de carcinicultura por eletro-oxidação Autor(es): Andrade, Ana Karolyne Fontes Abstract: The increasing occurrence of antibiotics in aquaculture effluents represents an environmental and public health challenge, mainly due to the induction of microbial resistance. Among these compounds, tetracycline stands out for its frequent use in shrimp farming. This study evaluated electrochemical oxidation as an advanced process for tetracycline degradation in shrimp-pond effluents, employing a filter-press reactor operated in closed recirculation with a metal-oxidebased anode (Ti/RuO₂–Sb₂O₄–TiO₂). Operational variable optimization (current density, time, and flow rate) was performed using a Central Composite Rotational Design (CCRD). Under optimal conditions (60 mA cm⁻², 3 h, 4 L min⁻¹), complete degradation was achieved in the real effluent within 10 min, with up to 99.42 % removal in the synthetic effluent. The energy consumption ranged from 6.7 to 16.8 Wh L⁻¹, resulting in an estimated cost of R$ 4.46–11.19 m⁻³ (at R$ 0.666 kW h⁻¹), which is competitive compared to systems using aluminum or iron electrodes. The physicochemical characterization of the effluent indicated pH values between 7.76 and 8.12, conductivity of 24 mS cm⁻¹, total nitrogen of 10.2 mg L⁻¹, and phosphate of 0.22 mg L⁻¹—the latter above the reference value for eutrophication prevention, yet close to the limits established by Brazilian Resolution CONAMA No. 430/2011. The electro-oxidation process led to a 32 % decrease in COD and an increase in BOD, evidencing partial oxidation of organic matter and the formation of more biodegradable intermediates. These findings demonstrate the potential of the electrochemical system as a pre-treatment stage, allowing integration with subsequent biological processes to enhance organic mineralization, nutrient removal, and overall environmental compliance. Electrochemical oxidation proved to be a promising, efficient, and environmentally safe alternative for the treatment of antibioticcontaminated aquaculture effluents, directly contributing to the United Nations Sustainable Development Goals (SDGs), particularly SDG 6 (Clean Water and Sanitation), SDG 3 (Good Health and Well-Being), and SDG 14 (Life Below Water).