Preparation and evaluation of chitosan beads immobilized with Iron(III) for the removal of As(III) and As(V) from water

Abstract

O adsorvente quitosana-Fe(III)-reticulado (Ch-FeCL) foi desenvolvido usando Fe(III) imobilizado em esferas de quitosana. Após o processo de secagem, as esferas apresentam um diâmetro de cerca de 1 mm e são estáveis ao ar. O comportamento de adsorção do As(III) e As(V) na Ch-FeCL foi avaliado em pH 7 por estudos realizados em batelada e em coluna. As máximas capacidades de adsorção estimadas pelo modelo de adsorção de Langmuir foram 21,24 e 27,59 mg g -1 para As(III) e As(V), respectivamente. A cinética de adsorção é descrita pela equação cinética de pseudo-segunda ordem. Os resultados de adsorção em coluna indicaram que o arsênio não foi encontrado na solução efluente até cerca de 60 e 759 volumes de leito para As(III) e As(V), respectivamente. Os resultados foram satisfatórios quando se empregou o adsorvente na remoção de As(III) e As(V) de amostras de águas subterrâneas, torneira e rio.The crosslinked chitosan-Fe(III) (Ch-FeCL) adsorbent was developed using Fe(III) immobilized on chitosan beads. After drying, the beads presented a diameter of approximately 1 mm and are stable in air. The adsorption behavior of As(III) and As(V) on the Ch-FeCL was evaluated at pH 7 by studies conducted in batch and in columns. Maximum adsorption capacities estimated by the Langmuir adsorption model were 21.24 and 27.59 mg g -1 for As(III) and As(V), respectively. Adsorption kinetics is described by the pseudo second order kinetic equation. The results of column adsorption indicated that arsenic was not found in the effluent solution from roughly 60 and 759 bed volumes for As(III) and As(V), respectively. Results were satisfactory when employing the adsorbent for removal of As(III) and As(V) from groundwater, tap water and river water samples.

Arsenic removal from water using a one-pot synthesized low-cost mesoporous Fe-Mn-modified biosorbent

“…Thus, the rapid adsorption of arsenic from an aqueous solution corresponding to external diffusion and slower arsenic adsorption, caused by intraparticle diffusion, limits the entire adsorption process on the synthesized adsorbents. Similar observation was reported in study Neto et al 24…”

“…15,16 This is in agreement with Neto el al. 24 who reported that diffractograms of chitosan beads crosslinked with glutaraldehyde (Ch--CL) present a much lower crystallinity index when chitosan beads are used for immobilization of Fe(III) (Ch-FeCL).…”

Uptake of Methylene Blue from Aqueous Solution by Pectin–Chitosan Binary Composites

“…An estimate of the PZC value for chitosan (ca. 6.5) has been reported [21], where changes in the PZC value upon the formation of pectin-chitosan composites reveals a unique material that differs relative to the biopolymer precursors. The reduced PZC value of the pectin-chitosan composite is within the range of an independent estimate (PZC = 4.4) [22].…”

Sorption of Hg(II) and Pb(II) Ions on Chitosan-Iron(III) from Aqueous Solutions: Single and Binary Systems

“…Nevertheless, few researchers have proposed chitosan-iron composite without further process in adsorbing metals and metalloids from water. Example of these are: As(III) and As(V) with Fe(III) immobilized on chitosan beads [ 14 ], and boron from seawater with chitosan iron(III) hydroxide beads [ 15 ]. However, two of the most toxic and highly relevant heavy metals, Hg(II) and Pb(II) have not been studied with this promising bio-based material.…”