Emerson Adriano Guarda

@uft.edu.br

Laboratório de Pesquisa em Química Ambiental - LAPEQ/CUP/UFT
Universidade Federal do Tocantins

Emerson Adriano Guarda


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https://researchid.co/emersonprof
Atualmente é professor associado da Universidade Federal do Tocantins (UFT), onde atua no curso de Engenharia Ambiental no PPG em Agroenergia Digital e no PPG em Biodiversidade e Biotecnologia Rede BIONORTE (PPG-BIONORTE). Tem experiência na área de Química, com ênfase em Química Orgânica. Coordena o Laboratório de Pesquisa em Química Ambiental e Biocombustíveis - LAPEQ, onde atua em pesquisas com líquidos iônicos, biopolímeros, química ambiental e biocombustíveis.

EDUCATION

Possui graduação em Química Industrial - Departamento de Química da Universidade Federal de Santa Maria (1997), mestrado em Engenharia de Minas, Metalúrgica e de Materiais pela Universidade Federal do Rio Grande do Sul (2001) e Doutorado em Química Orgânica pela Universidade Federal de Santa Maria (2009).

RESEARCH, TEACHING, or OTHER INTERESTS

General Chemistry, Environmental Chemistry, Renewable Energy, Sustainability and the Environment, Organic Chemistry
18

Scopus Publications

Scopus Publications

  • The Use of Ionic Liquids and Deep Eutectic Solvents in the Extraction of Phytochemicals with Bioactive Properties: A Review
    Erlane da Rocha Fernandes, Jefferson Henrique Tiago Barros, Patrícia Martins Guarda, Emerson Adriano Guarda
    Food Biophysics, 2025
  • Effect of foliar application of lithium on biofortification, physiological components, and production of irrigated rice
    Danilo Pereira Ramos, Guillermo Arturo Herrera Chan, Wanessa Rocha de Souza, Dayara Vieira Silva, Larissa Urzêdo Rodrigues, et al.
    Crop and Pasture Science, 2025
    Context Lithium (Li) is an essential trace element for human health. Although the biofortification of rice (Oryza sativa) with Li is a promising strategy to overcome its deficiency, little is known about its biological activity in plants. Aims We determined the effect of sources and doses of Li applied via the leaves on the biofortification, physiological components, and production of irrigated rice. Methods The experimental design consisted of randomised blocks in a 5 × 3 factorial arrangement, with four replicates. The factors consisted of five doses of Li (0, 50, 100 150, and 200 g ha−1) and three sources (lithium sulfate, Li2SO4·H2O; lithium hydroxide, LiOH·H2O; and lithium chloride, LiCl). Key results Regardless of the source used, foliar application of Li allowed bioaccumulation in rice grains without influencing the development and grain yield of the crop. Supplying Li to rice plants in the form of Li2SO4·H2O increased the photosynthetic rate and water use efficiency. Moreover, regardless of the source used, the consumption of rice grains biofortified with Li at a dose of 200 g ha−1 can supply more than 50% of the minimum recommended daily intake of the element. Conclusions Foliar spraying of Li is effective for agronomic biofortification of rice. Implications Biofortification of rice with Li can contribute to reducing its deficiency in naturally poor regions.
  • Application of Oil Extracted from Cashew Nut Peel (Anacardium occidentale) as an Antioxidant for Biodiesel
    Fabrício Ramos, Patrícia Guarda, Rosinete Sousa, Danylo Mendes, Fabiana Silva, et al.
    Journal of the Brazilian Chemical Society, 2025
    The present work aims to extract and test cashew nut peel oil as a natural antioxidant in the oxidative stabilization of biodiesel. Therefore, determinations of the ideal time of Soxhlet and thermal extractions, Fourier transform infrared spectroscopy (FTIR) analyses, and evaluation of the oxidative stability by Rancimat method were carried out. FTIR analyses revealed that the 3rd cycle of extraction was sufficient to extract all the oil, with an average yield of 30.0%. For the thermal extraction of the laboratory technical cashew nut peel oil, the best extraction, based on statistical analysis, was 60 min, yielding 20.0%. The FTIR analysis of the extracted cashew nut peel oil showed characteristic peaks of phenolic groups and organic acids, showing differences in the intensities of the absorption bands. The oxidative stability showed induction period of 8 h 40 min for the hydraulic press extraction, 10 h 35 min for the Soxhlet extraction, and 10 h 65 min for the industrial technical extraction of the cashew nut peel oil. All values were below the 12-h limit established by the National Agency for Petroleum, Natural Gas and Biofuels (ANP). The technical cashew nut peel oil extracted in the laboratory presented an induction period of 11 h 12 min, close to that recommended by ANP, proving to be a promising natural antioxidant. Cardanol presented satisfactory results with 25 h 22 min, double that suggested by ANP. Thus, cashew nut peel oil showed important and promising results as a natural antioxidant for biodiesel.
  • Pretreatment of Oryza sativa (Rice) and Musa cavendishii (Banana) Waste Biomass Using Ionic Liquids of Choline Amino Acid for Nanoscale Cellulose Production
    Fabiane da Silva, Danylo Mendes, Patrícia Guarda, Anselmo Rodriguez, Emerson Guarda
    Journal of the Brazilian Chemical Society, 2025
    The species Oryza sativa (rice) and Musa cavendishii (banana) are sources of cellulose-rich waste biomass in the Amazon region, Tocantins State. This research investigates the nanoscale production of cellulose through the interactions between three choline amino acid ionic liquids Ch[AA]IL and the respective fibers by pretreatment. To this end, the synthesis of three ILs was carried out: choline arginate Ch[Arg], choline glycinate Ch[Gly] and choline lysinate Ch[Lys], characterized by Fourier transform infrared spectroscopy (FTIR). The samples resulting from the pretreatment were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). It was possible to infer from the SEM micrographs that Ch[Arg] caused greater fiber breakage than the other ILs. The TEM analyses identified fibers up to 16 nm in diameter. Positive effects were observed in the diffractograms, although no crystallinity was obtained in the pretreated samples. Thermogravimetry curves showed that the fibers treated with Ch[Arg] showed higher thermal stability.
  • Use of ionic liquids in the pretreatment of lignocellulosic biomass
    Raiana Batista da Luz, Patricia Martins Guarda, Emerson Adriano Guarda
    Agroenergy Renewable and Sustainable Energy, 2023
  • Microbial metabolic activity in Amazon floodplain forest and agricultural soils
    Dayane J. Barros, Glauber A. Carvalho, Miriam G. de Chaves, Luiz S. Vanzela, Dora Inés Kozusny-Andreani, et al.
    Frontiers in Microbiology, 2023
    Microorganisms play an essential role in ecosystem functions. An increasingly used method for conducting functional analyses of a soil microbial community is based on the physiological profile at the community level. This method allows the metabolic capacity of microorganisms to be assessed based on patterns of carbon consumption and derived indices. In the present study, the functional diversity of microbial communities was assessed in soils from seasonally flooded-forest (FOR) and -traditional farming systems (TFS) in Amazonian floodplains flooded with black, clear, and white water. The soils of the Amazon floodplains showed differences in the metabolic activity of their microbial communities, with a general trend in activity level of clear water floodplain > black water floodplain > white water floodplain. The redundancy analysis (RDA) indicated that soil moisture (flood pulse) was the most important environmental parameter in determining the metabolic activity of the soil microbial communities in the black, clear, and white floodplains. In addition, the variance partitioning analysis (VPA) indicated that the microbial metabolic activity of the soil was more influenced by water type (41.72%) than by seasonality (19.55%) and land use type (15.28%). The soil microbiota of the white water floodplain was different from that of the clear water and black water floodplains in terms of metabolic richness, as the white water floodplain was mainly influenced by the low substrate use during the non-flooded period. Taken together, the results show the importance of considering soils under the influence of flood pulses, water types, and land use as environmental factors when recognizing functional diversity and ecosystem functioning in Amazonian floodplains.
  • Ultrasound Assisted Pretreatments Applied to Cupuaçu Husk (Theobroma grandiflorum) from Brazilian Legal Amazon for Biorefinery Concept
    Nicole Marasca, Isabella Cardoso, Magale Rambo, Daniel Bertuol, Michele Rambo, et al.
    Journal of the Brazilian Chemical Society, 2022
    Cupuaçu husk (CH) is the waste of a common fruit from a native species of the Brazilian Legal Amazon. The current study investigated the influence of ultrasound (US) combined with aqueous, acid, alkaline, and ionic liquid (IL) pretreatments on the chemical and physical aspects of CH and the yield of chemical platforms production, 5-hydroxymethylfurfural (HMF) and furfural (FF), using IL. Scanning electron microscopy, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy were used to feature the raw and pretreated biomass. The highest levels of glucose (9.90 g L-1) were observed in the liquid fraction resulting from the acid + US pretreatment followed by acid hydrolysis. The IL + US pretreatment recorded the best performance in removing lignin. Based on XRD analyses, ultrasound increased crystallinity of all pretreated samples as a result of the removal of cellulose’s amorphous fraction. However, it promoted accessibility to adopted reagents by increasing biomass exposure due to cavitation. The best yields of HMF and FF were recorded from hydrolysis of the solid fraction resulting from the acid + US (12.94%) and alkaline + US (48.84%) pretreatment, respectively. These results indicate satisfactory performance of ultrasound assisted pretreatments to the simplified and economic conversion of biomass into value-added products.
  • Assessment of Ecological Risk and Environmental Behavior of Pesticides in Environmental Compartments of the Formoso River in Tocantins, Brazil
    Patricia M. Guarda, Antonina M. S. Pontes, Raquel de S. Domiciano, Larissa da S. Gualberto, Danylo B. Mendes, et al.
    Archives of Environmental Contamination and Toxicology, 2020
  • Analysis of triazines, triazoles, and benzimidazoles used as pesticides in different environmental compartments of the Formoso River and their influence on biodiversity in Tocantins
    Patricia Martins Guarda, Larissa da Silva Gualberto, Danylo Bezerra Mendes, Emerson Adriano Guarda, José Expedito Cavalcante da Silva
    Journal of Environmental Science and Health Part B Pesticides Food Contaminants and Agricultural Wastes, 2020
  • Enzymatic cellulose hydrolysis for glucose obtainment using ionic liquid as a solvent medium
    Thaysi C. C. Andrade, Waldo C. Bitencourt, Fabrícia V. S. Bomtempo, Filipe S. Alves, Robson S. Barbosa, et al.
    Revista Virtual De Quimica, 2019
  • Lipolytic Enzymes with Hydrolytic and Esterification Activities Produced by Filamentous Fungi Isolated from Decomposition Leaves in an Aquatic Environment
    D. B. Mendes, F. F. Da Silva, P. M. Guarda, A. F. Almeida, D. P. de Oliveira, et al.
    Enzyme Research, 2019
  • Influence in chemical and physical pre-treatment with cellulose and lignin fractions of different biomasses and their capacity for second generation ethanol production
    Thaysi Castro Coelho Andrade, Lara Neira de Siqueira, Dener Alves de Souza, Fabricia Vieira Silva, Patricia Martins Guarda, et al.
    Revista Em Agronegocio E Meio Ambiente, 2018
  • Production of cellulases by Penicillium oxalicum through solid state fermentation using agroindustrial substrates
    Fabrícia Vieira Silva Bomtempo, Franciane Maria Mantovani Santin, Raphael Sanzio Pimenta, Deyla Paula de Oliveira, Emerson Adriano Guarda
    Acta Scientiarum Biological Sciences, 2017
  • Enol ethers and acetals: Acylation with dichloroacetyl, acetyl and benzoyl chloride in ionic liquid medium
    Emerson A. Guarda, Mara R.B. Marzari, Clarissa P. Frizzo, Patrícia M. Guarda, Nilo Zanatta, et al.
    Tetrahedron Letters, 2012
  • Ionic liquids promoted the C-acylation of acetals in solvent-free conditions
    Marcos A. P. Martins, Emerson A. Guarda, Clarissa P. Frizzo, Dayse N. Moreira, Mara R. B. Marzari, et al.
    Catalysis Letters, 2009
  • Ionic liquid as catalyst in the synthesis of N-alkyl trifluoromethyl pyrazoles
    Clarissa P. Frizzo, Dayse N. Moreira, Emerson A. Guarda, Gabriela F. Fiss, Mara R.B. Marzari, et al.
    Catalysis Communications, 2009
  • An ionic liquid as reaction medium for the synthesis of halo-containing β-enaminones at room temperature
    Marcos A. P. Martins, Emerson A. Guarda, Clarissa P. Frizzo, Mara R. B. Marzari, Dayse N. Moreira, et al.
    Monatshefte Fur Chemie, 2008
  • Synthesis of 1,1,1-trichloro[fluoro]-3-alken-2-ones using ionic liquids
    Marcos A.P. Martins, Emerson A. Guarda, Clarissa P. Frizzo, Elisandra Scapin, Paulo Beck, et al.
    Journal of Molecular Catalysis A Chemical, 2007