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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Item Preparação e caracterização de carvão ativado produzido a partir de resíduos do beneficiamento do café(Sociedade Brasileira de Química, 2008) Brum, Sarah Silva; Bianchi, Maria Lucia; Silva, Vanésia Liane da; Gonçalves, Maraísa; Guerreiro, Mário César; Oliveira, Luiz Carlos Alves deCoffee fruit processing is one of the most polluting activities in agriculture due to the large amount of waste generated in the process. In this work, coffee parchment was employed as precursor for the production of carbons activated with ZnCl2 (CAP). The material was characterized using N2 adsorption/desorption at 77 K, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The material showed a surface area of 521.6 m²g-1 and microporous structure. CAP was applied as adsorbent for the removal of methylene blue dye in aqueous medium. The adsorption capacity was found to be about 188.7 mg g-1.Item Impact of coffee biochar on carbon, microbial biomass and enzyme activities of a sandy soil cultivated with bean(Academia Brasileira de Ciências, 2021) Martins Filho, Argemiro P.; Medeiros, Erika V. de; Lima, José Romualdo S.; Costa, Diogo P. da; Duda, Gustavo P.; Silva, Jenifer S. A. da; Oliveira, Julyana B. de; Antonino, Antônio C. D.; Menezes, Rômulo S. C.; Hammecker, ClaudeBiochar has been used to reuse the agro-industrial wastes and improve soil quality. Several studies have been carried out to show the impact of biochar on physical and chemical soil attributes. However, there are still gaps regarding the effects on as microbial biomass and enzymatic activities that are important to determine sensitive indicators to evaluate changes in management practices. The objective of this study was to assess the effect of two biochars on the chemical, microbial biomass carbon, and the enzymatic activities in an Entisol cultivated with bean. We evaluate two types of coffee biochar: ground and husks, four doses (4, 8, 12, and 16 Mg ha-1) and control. All treatments received organic fertilization with cow manure. Husks biochar increase the soil pH, Ca, and K, also contributing to the reduction of toxic aluminum contentes and raising the concentrations of P labile. The treatments that received ground biochar showed higher soil organic carbon, microbial biomass, β-glucosidase, and fl uorescein diacetate. Biochar produced from coffee residues increased sandy soil quality. We showed the fi rst report on the benefi cial impact of coffee biochar on enzymatic and microbiological quality of sandy soil cultivated with the bean.Item Coffee waste biochars: characterization and zinc adsorption from aqueous solution(Editora UFLA, 2019-10) Sertoli, Lindiamara; Carnier, Ruan; Abreu, Cleide Aparecida de; Coscione, Aline Renée; Melo, Leônidas Carrijo AzevedoThe final disposal of organic wastes has become a major challenge with increasing industrialization and population growth. Coffee wastes can be converted into biochar and provide economic and environmental benefits, such as heavy metal remediation in different media. We produced biochars at 700 °C from spent coffee grounds and coffee parchment, characterized them physically and chemically and evaluated their Zn adsorption capacity from aqueous solution. Batch adsorption experiments were performed with six Zn concentrations using four replicates. The desorption process was performed sequentially with a pH 4.9 buffer acetic acid solution. Langmuir and Freundlich isotherms were fitted to the adsorption data using non-linear models. Results show that both biochars are alkaline and have high values of point of zero charge (PZC) (9.2 and 7.7 for coffee parchment and spent coffee grounds biochar). These characteristics indicate precipitation as the main mechanism of Zn immobilization and may have contributed to the low adsorption capacity obtained (0.056 and 0.792 mg g-1 for spent coffee ground and coffee parchment biochar, respectively). Although the biochars have shown low adsorption capacity, they bound Zn strongly and the adsorption process is not easily reversed.