Browsing by Author "Zimmermann, Juliano"

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    Adsorption of Cd (II), Pb (II) and Cr (III) on chemically modified Euterpe Oleracea biomass for the remediation of water pollution
    (UNIV ESTADUAL MARINGA, PRO-REITORIA PESQUISA POS-GRADUACAO, 2021) Goncalves Junior, Affonso Celso; Schwantes, Daniel; Conradi Junior, Elio; Zimmermann, Juliano; Coelho, Gustavo Ferreira
    This study evaluated the use of Euterpe oleracea endocarp after chemical modification with H2O2, H2SO4 and NaOH for the removal of Cd2+, Pb2+ and Cr3+ from water. Therefore, the adsorbent was characterized for its chemical composition, Fourier Transform Infrared (FTIR) analysis, Scanning Electron Microscope (SEM) images, and pH of point of zero charge (pH(PZC)), thermal stability and porosimetry. Adsorption tests were conducted by using a Central Composite Design (CCD). Pseudo-first order, pseudosecond order, Elovich and intraparticle diffusion models evaluated the adsorption kinetics, and sorption isotherms were linearized according to Langmuir, Freundlich and Dubinin- Radushkevich. The effect of initial concentration, temperature in the process and the desorption were also analyzed. SEM results showed that the acai adsorbents (or CA) had irregular and heterogeneous structure, and IR analysis evidenced the presence of hydroxyl, aliphatic, phenolic and carboxylic surface groups; both analyses indicate favorable adsorption characteristics. The pHPZC of the adsorbent is 4.41, 4.02 and 7.10 for CA modified with H2O2, H2SO4 and NaOH, respectively. The optimum adsorption conditions were pH 5.0, within 40 min, with 4 g L-1 as the ideal adsorbent dose. The predominance of chemisorption occurs, in mono and multilayer. The adsorption is only spontaneous for Cd2+ at 15 and 25 degrees C. The CA has the potential to increase the removal efficiency of Cd, Pb and Cr, when chemically modified, particularly with H2O2 and H2SO4.
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    Development of biochar and activated carbon from cigarettes wastes and their applications in Pb2+ adsorption
    (2021) Manfrin, Jessica; Goncalves Jr, Affonso Celso; Schwantes, Daniel; Conradi Jr, Elio; Zimmermann, Juliano; Ziemer, Guilherme Lindner
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    Distribution of heavy metals in sediments and their bioaccumulation on benthic macroinvertebrates in a tropical Brazilian watershed
    (2021) Schwantes, Daniel; Goncalves Junior, Affonso Celso; Manfrin, Jessica; Campagnolo, Marcelo Angelo; Zimmermann, Juliano; Conradi Junior, Elio; Bertoldo, Danieli Cristina
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    Evaluation of benthic macroinvertebrates as indicators of metal pollution in Brazilian rivers
    (TAYLOR & FRANCIS LTD, 2021) Manfrin, Jessica; Schwantes, Daniel; Goncalves, Affonso Celso, Jr.; Schiller, Andreia da Paz; Zimmermann, Juliano; Dias de Oliveira, Vinicius Henrique
    The evaluation of water resources quality is an important tool for controlling and monitoring water bodies, among which, the evaluation of toxic metal levels in benthic macroinvertebrates has been highlighted. This study aimed to evaluate the biological quality of the Alvorada and Mandaguari rivers and to evaluate the metal bioaccumulation by means of the metal concentrations in surface waters, bottom sediments and benthic macroinvertebrates. Samples of water, biological material and sediments were conducted at six sampling points, 3 points in each river during 12 months. Macroinvertebrates were sorted, identified and analysed from the biological metrics, BMWP' index and statistical analyses. The samples of benthic macroinvertebrates and sediments were submitted to nitroperchloric digestion for further determination of the metal content. The metal concentrations in sediment had become high in both rivers, reaching values of up to 1752.50 mg kg(-1) of Pb in point M1 and 53.80 mg kg(-1) of Cd in point M3. Macroinvertebrate tissues exhibited high levels of toxic metals, reaching values of 146.11 mg kg(-1) of Cr in point M1, 144.28 mg kg(-1) of Pb and 3.11 mg kg(-1) of Cd in point M3, which indicates the occurrence of bioaccumulation and insertion in the food chain. The results from the evaluation using the BMWP' index do not present the real conditions of the watersheds, which suggests a review of the evaluation method. In addition, the environmental evaluation using macroinvertebrates is a good tool to verify the impacts in a river.
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    Potential of agricultural and agroindustrial wastes as adsorbent materials of toxic heavy metals: a review
    (2020) Schiller, Andreia da Paz; Goncalves, Affonso Celso, Jr.; Braccini, Alessandro de Lucca; Schwantes, Daniel; Campagnolo, Marcelo Angelo; Conradi, Elio, Jr.; Zimmermann, Juliano