Optimization of the Production Parameters of Composites from Sugarcane Bagasse and Iron Salts for Use in Dye Adsorption

Abstract

In this study, mechanical mixtures of sugarcane bagasse and iron salts (nitrate, acetate, or a mixture of both) were subjected to thermal decomposition for producing iron oxide and carbonaceous composite materials, which were evaluated as adsorbents for removing dyes from water using methylene blue (MB) as a model system. Aiming to optimize the conditions for obtaining composite adsorbents, the Box-Behnken design (BBD) was used to study the effects of mass sugarcane bagasse/mass iron salt, type of mixture of sugarcane bagasse/iron salt, and temperature on the response to be obtained (adsorption capacity, qe) before the execution of the adsorption tests. The synthesized composites were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. The relationship between the characteristics of different materials, based on the processing of statistical data and the results of the adsorption tests, helped determine the routes that led to formation of composites with the most suitable properties for the removal of MB dye. Different phases, such as magnetite (Fe3O4) and/or maghemite (γ-Fe2O3) and iron carbide (Fe3C), were formed. The composites that presented the highest qe values were SB/IN 1:1 (600°C) and SB/IN-IA 1:2 (400°C). The first, which contained iron carbide (Fe3C), according to the XRD results, also showed larger BET surface area than the other composites. These properties may have contributed to the higher MB adsorption efficiency of this material in aqueous medium. The sample SB/IN-IA 1:2 (400°C) had lower specific area and was composed of magnetite and/or maghemite phases. In this case, the high qe was probably associated with the surface properties promoted by combination with the carbonaceous material, favoring interactions with MB.

Modified Beaded Materials from Recycled Wastes of Bagasse and Bagasse Fly Ash with Iron(III) Oxide-Hydroxide and Zinc Oxide for the Removal of Reactive Blue 4 Dye in Aqueous Solution

“… 15 Especially, iron(III) oxide-hydroxide and ZnO are usually used for improving material efficiency to remove dyes in many articles. 16 − 19 Metal oxides are not appropriate for direct use in dye removal in effluents because they might cause problems including clogging, pressure drop, and being hard to separate after treatment. 20 Therefore, the adsorbent efficiencies are improved by adding them to raw materials.…”

“…Many types of metal oxides such as titanium dioxide (TiO 2 ), aluminum oxide (Al 2 O 3 ), manganese oxide (MnO), iron oxide (FeOH), and zinc oxide (ZnO) have been used for dye removal in various applications . Especially, iron­(III) oxide-hydroxide and ZnO are usually used for improving material efficiency to remove dyes in many articles. − Metal oxides are not appropriate for direct use in dye removal in effluents because they might cause problems including clogging, pressure drop, and being hard to separate after treatment . Therefore, the adsorbent efficiencies are improved by adding them to raw materials.…”

Solution Combustion Synthesis of Environmentally Friendly Magnetic Composites Based on Iron Oxide and Mango (Mangifera Indica L.) waste for UV and Solar - Driven Heterogeneous Photocatalysis

“…The in natura residue can be added to the synthesis of iron oxides, modifying the reaction atmosphere and, consequently, the product formed [25]. The decomposition of the residue itself [26] can generate carbon, which will serve as a support for the iron oxide and can cause changes in the solid that help to increase the recombination time of the electron/hole pair, [27].…”