Powdered and beaded sawdust materials modified iron (III) oxide-hydroxide for adsorption of lead (II) ion and reactive blue 4 dye

Abstract

The problems of lead and reactive blue 4 (RB4) dye contamination in wastewater are concerns because of their toxicities to aquatic life and water quality, so lead and RB4 dye removals are recommended to remove from wastewater before discharging. Sawdust powder (SP), sawdust powder doped iron (III) oxide-hydroxide (SPF), sawdust beads (SPB), and sawdust powder doped iron (III) oxide-hydroxide beads (SPFB) were synthesized and characterized with various techniques, and their lead or RB4 dye removal efficiencies were investigated by batch experiments, adsorption isotherms, kinetics, and desorption experiments. SPFB demonstrated higher specific surface area (11.020 m2 g−1) and smaller pore size (3.937 nm) than other materials. SP and SPF were irregular shapes with heterogeneous structures whereas SPB and SPFB had spherical shapes with coarse surfaces. Calcium (Ca) and oxygen (O) were found in all materials whereas iron (Fe) was only found in SPF and SPFB. O–H, C–H, C=C, and C–O were detected in all materials. Their lead removal efficiencies of all materials were higher than 82%, and RB4 dye removal efficiencies of SPB and SPFB were higher than 87%. Therefore, adding iron (III) oxide-hydroxide and changing material form helped to improve material efficiencies for lead or RB4 dye adsorption. SP and SPB corresponded to Langmuir model related to a physical adsorption process whereas SPF and SPFB corresponded to the Freundlich model correlated to a chemisorption process. All materials corresponded to a pseudo-second-order kinetic model relating to the chemical adsorption process. All materials could be reused more than 5 cycles with high lead removal of 63%, and SPB and SPFB also could be reused more than 5 cycles for high RB4 dye removal of 72%. Therefore, SPFB was a potential material to apply for lead or RB4 dye removal in industrial applications.

Modification of sugarcane bagasse with iron(III) oxide-hydroxide to improve its adsorption property for removing lead(II) ions

“…This result agreed with the pH pzc results of this study which the pH pzc values of all materials were found at pH > 4. Moreover, it also corresponded to other previous studies that reported the highest lead removal efficiency at pH > 4 relating to pH pzc of lead adsorptions in an aqueous solution 33,37,45,46 . Therefore, pH 5 was the optimum pH of all sugarcane bagasse adsorbent materials which were used for studying the concentration effect.…”

“…In Fig. 6d, lead removal efficiencies of all materials were decreased with www.nature.com/scientificreports/ the increase of concentration because lead ions were more than the available active sites of bagasse adsorbent materials similar to the report by other studies 9,33,37,38,45 . Lead removal efficiencies from 5 to 30 mg/L of SB, SBF, SBB, and SBFB were 40.63-100%, 92.78-100%, 78.07-100%, and 96.19-100%, respectively.…”

“…In Fig. 6a, lead removal efficiencies of all materials were increased with the increase of material dose which might be from the increase of surface area or active sites of materials similarly found in previous studies 33,37,38,45 . The highest lead removal efficiency of SB was 84.29% at 0.6 g whereas the highest lead removal efficiencies of SBF, SBB, and SBFB were 100% at 0.2 g, 0.2 g, and 0.1 g, respectively.…”

“…For SB and SBF, the mass percentages by weight of C and O were decreased when iron(III) oxide-hydroxide was added to SB, whereas the mass percentage by weight of Ca, Na, Cl, and Fe were increased. The increase in those chemical compositions might be from using chemicals in a process of adding iron(III) oxide-hydroxide by ferric chloride hexahydrate (FeCl 3 •6H 2 O) and sodium hydroxide (NaOH) similar to a previous study reported 37 .…”

Zeolite A powder and beads from sugarcane bagasse fly ash modified with iron(III) oxide-hydroxide for lead adsorption

“…The peels of potato, banana, and lemon are used as food waste adsorbents for lead removal [11][12][13] . For industrial wastes, sawdust, coal fly ash, and sugarcane bagasse fly ash have been used for removing lead and arsenic in an aqueous solution [14][15][16][17] . Therefore, adsorbents from waste are an interesting choice because not only they help to improve water quality for environmental remediation purposes but also using them is another benefit to waste treatment and management in terms of recycling natural resources.…”