Activated carbon from macauba endocarp (Acrocomia aculeate) for removal of atrazine: Experimental and theoretical investigation using descriptors based on DFT

Autor(es)

Vieira, Wedja Timoteo ^[1] ; Bispo, Mozart Daltro ^[1] ; Farias, Samara de Melo ^[1] ; Vasconcelos de Almeida, Arthur da Silva ^[1] ; da Silva, Thiago Lopes ^[1] ; Adeodato Vieira, Melissa Gurgel ^[2] ; Soletti, Joao Inacio ^[1] ; Balliano, Tatiane Luciano ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Alagoas, Av Lourival de Melo Mota S-N, BR-57072970 Maceio, AL - Brazil

^[2] Univ Estadual Campinas, Av Albert Einstein 500, BR-13083852 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING; v. 9, n. 1 FEB 2021.
• Citações Web of Science: 4

Resumo

In this work the properties of activated carbon obtained from macauba endocarp were evaluated, an agroindustrial waste widely produced in Brazil. This material was applied to remove the herbicide atrazine, an emerging pollutant. The biochar it was produced by vacuum pyrolysis (temperatures of 400 degrees C and 600 degrees C; heating rates 10 and 50 degrees C min(-1)) and activated with K2CO3. The characterizations of materials were performed by elemental analysis (CNHO), immediate analysis, TG/DTG, density, FTIR, DRX, SEM and surface area analysis by the N-2 adsorption and desorption method. Chemical reactivity of the atrazine molecule was investigated using DFT-based reactivity descriptors. For the kinetic profile and mechanism proposal, rate equations of pseudo-first-order, pseudo-second-order and intraparticle diffusion were considered. Activated carbons showed a typical amorphous structure, with an increase in the porous cavity after chemical activation process. Surface areas of 951-1002.5 m(2) g(-1) were obtained after activation with pores in the range of 1.70-2.67 nm. Activated carbons showed a high affinity with atrazine with a 90-98% removal percentage. The quantum chemical parameters calculated were the energy of the HOMO (E-H = -6.4649) and LUMO (E-L = -0.4558) orbitals, global chemical hardness (eta = 3.0045), chemical potential (mu = 3.4603) and the global electrophilicity index (omega = 1.9926). In the kinetic study, the pseudo-second-order model was more predictive in adsorption tests. These results suggest that macauba endocarp activated carbon is efficient in atrazine removal, in addition to being a strategy for using agroindustrial waste. (AU)

• Processo FAPESP: 16/05007-1 - Remoção de fármacos residuais em solução aquosa por adsorventes alternativos
• Beneficiário: Meuris Gurgel Carlos da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 19/11353-8 - Centro Brasileiro de Pesquisa em Água (BWRC)
• Beneficiário: Lauro Tatsuo Kubota
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia