High performance maleated lignocellulose epicarp fibers for copper ion removal

Abstract

-Natural lignocellulosic fiber epicarp extracted from the babassu coconut (Orbignya speciosa) was chemically modified through reaction with molten maleic anhydride without solvent, with incorporation of 189.34 mg g -1 of carboxylic acid groups into the biopolymer structure. The success of this reaction was also confirmed by the presence of carboxylic acid bands at 1741 and 1164 cm -1 in the infrared spectrum. Identically, the same group is observed through 13 C NMR CP/MAS in the solid state, via high field signals in the 167 pm region. Both the precursor and the immobilized maleated biopolymers presented nearly the same thermal stability and similar crystallinity to cellulose. However, the pendant carboxylic groups have the ability to remove copper with maximum sorption through a batchwise process at pH 6.0, as expected from the point of zero charge, determined to be 6.45. The sorption kinetic data were fitted to pseudo-first order, pseudo-second order, Elovich-chemisorption and intra-particle diffusion models and the equilibrium data were fitted to the Langmuir, the Freundlich and Tenkim isotherm models. Taking into account a statistical error function and determination coefficients, the data were fit to the pseudo-first and pseudo-second order kinetic and Langmuir isotherm models, with a maximum sorption capacity of copper ions of 55.09 mg g -1 . This value suggests the application of this biopolymer with incorporated carboxylate groups as a favorable agent for copper removal from appropriate systems.

Heavy metal ions and organic dyes removal from water by cellulose modified with maleic anhydride

“…11 shows the linear plots of adsorption isotherm for the adsorbate adsorption on CM at the optimum temperature. Langmuir isotherm model [36]: Table 1 Pseudo-first-order and pseudo-second-order models for adsorption of adsorbate Adsorbate Kinetics models Parameters …”

Subprodutos do babaçu (Orbignya sp)como novos materiais adsortivos: uma revisão

“…O babaçu é um biopolímero, constituído principalmente por fibras lignocelulósicas [8,25]. E devido às ligações inter e intramoleculares que a liginina e a celulose são capazes de realizar, suas fibras tem capacidade adsortiva [34].…”

“…Os subprodutos do babaçu vêm se mostrando como materiais altamente eficientes e interessantes para serem utilizados na adsorção de corantes [8,10,[13][14][15]22], íons [10][11][12][23][24][25], entre outras moléculas químicas [18,35]. Percebe-se, portanto, que as substâncias já adsorvidas em babaçu são moléculas pequenas e de difícil remoção por outros métodos.…”

“…O epicarpo de babaçu também foi modificado apenas com anidrido maleico fundido sem solvente, o que garantiu a presença de grupo de ácidos carboxílicos na estrutura e, consequentemente, essa transformação tornou o epicarpo mais semelhante à celulose. No entanto, os grupos carboxílicos pendentes tem a capacidade de remover o cobre com o máximo de absorção através de um processo em descontínuo, melhorando o processo de adsorção [25].…”

Biosorption of Mn (II), Co (II) and Cr (VI) in a horizontal rotating tubular bioreactor: experiments and evaluation of the integral bioprocess model

“…As an alternative, different biological methods could be applied because they do not destroy metals, but concentrate and immobilize them (Gavrilescu, 2004;Vieira et al, 2012;Michalak et al, 2013;Sicupira et al, 2014;Vieira et al, 2014). Biosorption is the removal of metals and their complexes by biological materials such as active or inactive microorganisms, microbial aggregates or biofilms (Singh et al, 2006;Baysal, et al, 2009;Xie, et al, 2013).…”