Navegando por Autor "Maia, Luisa Cardoso"
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Item Batch and continuous adsorption of Cd(II) and Pb(II) on polycarboxylated sugarcane bagasse.(2023) Carvalho, Megg Madonyk Cota Elias; Soares, Liliane Catone; Maia, Luisa Cardoso; Taylor, Jason Guy; Herrera Adarme, Oscar Fernando; Ferreira, Gabriel Max Dias; Azevedo, Eduardo Ribeiro de; Siervo, Abner de; Silva, Luis Henrique Mendes da; Gurgel, Leandro Vinícius AlvesA bioadsorbent composed of polycarboxylated sugarcane bagasse (PSB) was prepared in a one-step reaction by the esterification of sugarcane bagasse hydroxyl groups with butane-1,2,3,4-tetracarboxylic dianhydride. 13C SS NMR measurements showed that 0.3 butane-1,2,3,4-tetracarboxylic acid units were grafted per cellobiose unit. PSB was used in the batch adsorption of Cd(II) and Pb(II) from mono-, bi-, and multicomponent aqueous solutions. For upscaling of the technology aiming at practical applications, evaluation was made of 4 cycles of continuous adsorption of Cd(II) and Pb(II) on PSB in a fixed-bed column. The maximum adsorption capacities for Cd(II) and Pb(II) on PSB in batch and continuous modes were 0.55 and 1.164 mmol g− 1 (62 and 241.2 mg g− 1 ), and 0.58 and 0.71 mmol g− 1 (65 and 153 mg g− 1 ), respectively. The standard adsorption enthalpy change (ΔadsH◦) values for Cd(II) and Pb(II) were 8.6 ± 0.5 and − 0.28 ± 0.03 kJ mol− 1 , respectively. The interactions involved in the adsorption of Cd(II) and Pb(II) on PSB were investigated. Multicomponent studies showed that Pb (II) and Cd(II) acted to suppress the adsorption of each other. In the presence of Cu(II) and Zn(II), the adsorption capacity followed the order: Pb(II) > Cu(II) > Cd(II) > Zn(II). Batch and continuous adsorption-desorption studies showed that PSB could be reused in at least 4 successive cycles, with desorption efficiencies of 88–100 %, which is essential for minimizing waste generation and reducing process costs.Item Iron recovery from the coarse fraction of basic oxygen furnace sludge. Part I : optimization of acid leaching conditions.(2020) Maia, Luisa Cardoso; Santos, Grazielle Rocha dos; Gurgel, Leandro Vinícius Alves; Carvalho, Cornélio de FreitasIn this study, a new reuse process of the coarse fraction of basic oxygen furnace (BOF) sludge based on iron recovery by the ferrous sulfate production was proposed. This study was based on three main steps: (i) characterization of the steel waste, (ii) evaluation and optimization of the recycling process, and (iii) characterization of ferrous sulfate produced. Acid leaching was used to solubilize the iron for obtaining ferrous sulfate heptahydrate. The ferrous sulfate crystallization was performed by adding anhydrous ethanol (EtOH). A multivariate optimization for iron leaching and ferrous sulfate precipitation in the same solution was employed. This optimization consisted of screening steps using a full factorial design followed by optimization. The coarse fraction of BOF sludge was predominantly composed of iron in metallic form (82.5%, dry weight). The sulfuric acid concentration and leaching time had significant effects on Fe(II) solubilization. The desirability function predicted the following optimized conditions: 20% (v/v) sulfuric acid solution, 200 min of leaching time, 7.00 g of waste, and 110 mL of anhydrous EtOH, producing 19.60 g of ferrous sulfate heptahydrate (yield of 70.8%). The characterization of ferrous sulfate was performed by X-ray diffraction, scanning electron microscopy coupled to energy-dispersive X-ray spectroscopy, thermogravimetric anal ysis, and differential scanning calorimetry. The characterization of the ferrous sulfate produced evidenced the effectiveness of the optimized process condition.Item Multivariate optimization applied to the synthesis and reuse of a new sugarcane bagasse‑based biosorbent to remove Cd(II) and Pb(II) from aqueous solutions.(2022) Carvalho, Megg Madonyk Cota Elias; Soares, Liliane Catone; Maia, Luisa Cardoso; Dias, Mariana Viviane Lima; Gurgel, Leandro Vinícius AlvesThis study reports the use of multivariate tools to optimize the synthesis of a new agricultural-based biosorbent derived from sugarcane bagasse (SB) for the removal of Cd(II) and Pb(II) from aqueous solutions, as well as to optimize the process of desorption of these ions from the spent biosorbent using an acidic solution. The efects of the reaction parameters temperature (T), time (t), and the ratio of 1,2,3,4-butanetetracarboxylic acid dianhydride (BTCAD) to raw SB (wBTCAD wraw SB −1) on the chemical modifcation of raw SB with BTCAD and on the equilibrium adsorption capacity (qe) for Cd(II) and Pb(II) were investigated by application of a 23 Doehlert experimental design (DED), followed by optimization using a statistical desirability tool to produce the best adsorbent in terms of performance and cost. The best reaction condition was wBTCAD wraw SB −1 of 4.0 g g−1, t of 1 h, and T of 70 ºC. The optimal synthesis condition resulted in a modifed sugarcane bagasse (MSB) that provided qe values for Cd(II) and Pb(II) of 0.50 and 0.61 mmol g−1, respectively, obtained under the following conditions: 0.311 mmol Cd(II) L−1, 0.632 mmol Pb(II) L−1, pH 5.0, 4 h, 0.2 g L−1 MSB, 130 rpm, and 25 °C. The desorption of Cd(II) and Pb(II) from MSB was investigated by a 22 DED, with optimization using the desirability tool to obtain the best desorption condition in terms of HNO3 solution concentration (퐶HNO3 ) and t. The desorption efciencies for Cd(II) and Pb(II) were 90±4% and 88±3%, respectively, obtained using 0.7 mol L−1 HNO3, t of 42 min, and 1.0 g L−1 MSB-M(II) (M=Pb or Cd). Infrared spectroscopy was used to investigate the natures of the interactions involved in the adsorption of Cd(II) and Pb(II) on MSB, as well as possible changes in the chemical structure of MSB after desorption. The synthesis of MSB can be performed under mild reaction conditions (t=1 h, T=70 ºC), and the solvents used can be recovered by distillation. BTCA is commercially available at moderate cost and can alternatively be obtained employing microbial succinic acid, metal-free catalysis, and modest use of petrochemical feedstocks. Furthermore, MSB can be reused, which could contribute to increasing the economic feasibility of water and wastewater treatment processes.Item A review on the design and application of bi-functionalized adsorbents to remove different pollutants from water.(2023) Bukva, Merima; Soares, Liliane Catone; Maia, Luisa Cardoso; Costa, Camila Stéfanne Dias; Gurgel, Leandro Vinícius AlvesThis review provides a bibliometric analysis of chemically bi-functionalized materials that have been employed as advanced adsorbents to remove various types of organic and/or inorganic (cationic and/or anionic) pollutants from water and wastewater. The relevance of regeneration and reuse experiments for bi-functionalized adsorbents is discussed, since they have been shown to be fundamental in advancing the technology readiness level (TRL) and for assessing technical, economic, and environmental feasibility. Only 56% of the studies compiled in this review carried out regeneration and reuse experiments, and few studies have proposed and discussed waste management of adsorbents after depletion of their adsorption capacity. The aim of the present critical analysis is to inform and encourage researchers in this field, given the lack of in-depth information in the literature concerning advanced materials especially designed for the simultaneous removal of different types of pollutants coexisting in complex aqueous matrices in various environments, which slows transfer of the technology to the market. Among the compiled support materials, the most investigated were silica-based (~46%), followed by polymers (~15%) and biomass (~11%), with the adsorption capacity (Qmax) of bi-functionalized adsorbents outperforming mono-functionalized adsorbents, in most cases. For inorganic pollutants, the highest and lowest Qmax values of 4.67 and 1.51 mmol g− 1 for Cr(VI) were reported for polymer- and silica-based adsorbents, respectively. Biomass- and xerogel-based adsorbents were the most efficient for organic compounds, with Qmax values of 39.2 and 2.61 mmol g− 1 for trichloroacetic acid and methylene blue, respectively. In summary, the results were promising, but advances are still needed, since most of the developed technologies presented low TRL of ≤4, representing a challenge for transition of the technologies to the pilot scale (TRL ≥ 6) or for transfer to the market.Item A review on the use of lignocellulosic materials for arsenic adsorption.(2021) Maia, Luisa Cardoso; Soares, Liliane Catone; Gurgel, Leandro Vinícius AlvesIn this review, bibliometric analysis was made of recent studies and current trends concerning the application of lignocellulosic materials as bioadsorbents for the removal of arsenic from aqueous systems. Evaluation was made of lignocellulosic adsorbents and their chemical characteristics, as well as interactions involved in the adsorption of arsenic, bioadsorbent reusage (desorption and re-adsorption), competition between co-existing ions in multielement aqueous solutions, and applications of bioadsorbents in batch and continuous systems. Lignocellulosic biomass has been shown to be a promising source of new adsorbents, since it is a low-cost and renewable material. However, there seems to be no commercially available technology that uses bioadsorbents based on lignocellulosic biomass for arsenic removal. In addition, the structural modification of lignocellulosic biomass to improve its adsorption capacity and selectivity has proved to be a suitable strategy, with the service time and the selectivity of the bioadsorbent in the presence of co-existing ions the most critical aspects to be pursued. The competitive adsorption of co-existing anions (PO4 3− , SO4 2− , NO3 − , and Cl− ) by the adsorption sites, as well as life−cycle assessment and cost analysis are rarely reported. Complexation, electrostatic attraction, ion exchange and precipitation were the main interactions involved in the adsorption of arsenic on lignocellulosic materials. However, most studies have failed to prove the nature of the interactions. Macroscopic methods can be useful to evaluate the adsorption mechanism of arsenic on bioadsorbents of complex structure, such as lignocellulosic biomass (modified or not). Nevertheless, the elucidation of the adsorption mechanism requires experiments based on measurements at the microscopic level. The upscaling of biosorption technology for arsenic removal will only be possible through studies that investigate: i) the interactions involved in the adsorption process; ii) the transfer of bench-scale experiments to pilot-scale experiments with real contaminated water with low arsenic concentration; and iii) the life-cycle assessment of biosorbents produced from lignocellulosic biomass.Item Viabilidade de obtenção de sulfato ferroso a partir de lamas de aciaria.(2018) Maia, Luisa Cardoso; Carvalho, Cornélio de Freitas; Carvalho, Cornélio de Freitas; Yoshida, Maria Irene; Gurgel, Leandro Vinícius AlvesAs lamas de aciaria são resíduos gerados globalmente em grandes quantidades nas indústrias siderúrgicas integradas, sendo caracterizadas pela presença de certos contaminantes, impossibilitando, na maioria das vezes, a sua reutilização direta e tornando-as um resíduo de gerenciamento problemático. Nesse sentido, o presente trabalho tem por pressuposto a avaliação do potencial de recuperação de ferro proveniente de tais resíduos para produção de sulfato ferroso (FeSO4). Para isso, definiu-se a rota de obtenção do subproduto de interesse a partir de uma lixiviação ácida utilizando-se ácido sulfúrico como agente lixiviante, promovendo, posteriormente, a precipitação do sulfato ferroso através da adição de álcool etílico absoluto. Para tal, empregou-se uma otimização multivariada que consistiu de estudos de triagem a partir do Planejamento Fatorial Completo 2³, seguido de uma otimização a partir do Central Composite Design (CCD) e do Planejamento Doehlert. Os resíduos apresentaram elevados teores de ferro, observando-se a predominância da espécie de interesse – Fe(II), sendo constituídos majoritariamente por partículas com granulometria inferior a 0,5 mm. A lama grossa apresentou um teor de ferro total (FeT) de 81,02% e um teor de Fe(II) de 80,17%, enquanto a lama fina apresentou um teor de FeT e Fe(II) de 45,62% e 41,43%, respectivamente, com todos os teores expressos em massa. O tempo de lixiviação e a concentração da solução de ácido sulfúrico (H2SO4) apresentaram efeitos significativos sobre a extração de Fe(II). Por meio do CCD foi possível lixiviar toda a fração de Fe(II) contida na lama grossa, obtendo-se um teor de Fe(II) de cerca de 80% no lixiviado, utilizando-se, para isso, de um tempo de 179 minutos, 1,0 g de resíduo (L/S = 50) e uma solução de H2SO4 33% (v/v). De posse da condição ótima de lixiviação de ferro, determinou-se a condição otimizada do processo de precipitação de sulfato ferroso, verificando-se a incompatibilidade entre o ponto ótimo de lixiviação e o ponto ótimo de precipitação de sulfato ferroso. O Planejamento Doehlert foi capaz de construir um modelo mais robusto, uma vez que os perfis elaborados pela função desejabilidade apresentaram uma melhor predição para as variáveis resposta, obtendo-se a seguinte condição otimizada: solução de H2SO4 20% (v/v), tempo de lixiviação de 200 min., 7,00 g de resíduo e 110 mL de álcool etílico absoluto, produzindo 19,5961 g de FeSO4.7H2O (rendimento de 70,79%). No que se refere à lama fina, foram alcançados maiores rendimentos utilizando-se menores tempos de lixiviação, o que provavelmente se deve à sua menor granulometria assim como sua composição (presença predominante de FeO), favorecendo o processo de extração de Fe(II). Tais resultados foram obtidos por meio da utilização do Planejamento Doehlert, produzindo-se 13,0618 g de FeSO4.7H2O e um elevado rendimento (90,51%) a partir da seguinte condição otimizada: solução de H2SO4 13% (v/v), tempo de lixiviação de 140 min., 7,00 g de resíduo e 120 mL de álcool etílico absoluto. Por fim, realizou-se uma caracterização qualitativa das amostras de FeSO4 proveniente de lama grossa por meio de Difração de Raios X (DRX), verificando-se a presença de sulfato ferroso heptahidrado (FeSO4.7H2O), subproduto de interesse. Dessa maneira, notou-se que a rota química proposta possibilitou a obtenção de rendimentos satisfatórios para o processo de produção de sulfato ferroso, tanto para lama grossa quanto para lama fina, salientando-se o potencial de aplicação industrial do processo otimizado.