Soybean hull as an alternative biosorbent to uptake a reactive textile dye from aqueous solutions

Abstract

The textile industries are responsible for generating large volumes of effluents containing toxic dyes, harmful to ecosystems if disposed of without prior treatment. The adsorption process stands out due to its simplicity and efficiency in removing a wide variety of contaminants present in effluents, also, it allows the use of residual biomass from agriculture. The soybean hull is a by-product of wide available but made used only for animal feed. Thus, the present study aimed to characterize and evaluate the soybean husk as a biosorbent of the 5G blue reactive dye, widely used in the dyeing processes of the textile industries. The soybean hull was characterized by SEM and FTIR. Kinetic and equilibrium tests were carried out under conditions of pH 2, 40 ºC, and 90 rpm. Besides, kinetic and equilibrium mathematical models previously described in the literature were adjusted to the experimental data. Through the morphological characterization of the biosorbent, it was possible to evidence superficial pores in practically all their extension, a characteristic that directly influences the adsorption process. The analysis of FTIR showed, as expected, the presence of functional groups characteristic of lignocellulosic substances. Besides, the results obtained in the kinetic and equilibrium essays in the studied conditions show that the adsorption equilibrium was obtained in about 120 min, with the removal of 88% of the dye. The mathematical modeling indicated that the pseudo-second order and Sips models were the most adequate to represent the kinetic and equilibrium experimental data, respectively. The maximum adsorption capacities calculated experimentally and predicted by the Sips model were 53.33 and 48.13 mg g -1 , respectively. In general, the biosorbent studied was effective to remove the reactive dye.

Adsorbents for the purification and recovery of biocompounds: An updated review

“…Metal ions are retained on the surface of biosorbents by individual or simultaneous different techniques, such as condensation of hydroxides on the surface and adsorption on the surface. 71 The mechanisms that occur during the retention of metallic ions in plant-derived biosorbents are directly related to the chemical functional groups in the material. 72 These groups are normally present in structures contained in the cell wall of the biomaterial, which include cellulose macromolecules organized in the form of microfibrils surrounded by hemicelluloses, lignin, pectin and small portions of vegetable proteins.…”

“…76 Biosorbents are obtained through two basic steps: carbonization by pyrolysis of the precursor material and activation. 71 Carbonization or pyrolysis is usually carried out at 500-800°C, while activation is carried out with oxidizing gases from 800 to 900°C. 71 Biosorbent performance is related to its chemical characteristics and porous structure.…”

Tannery wastes-derived gelatin and carbon nanotubes composite beads: adsorption and reuse studies using tartrazine yellow dye

“…Afterward, aliquots of the samples were taken to read the concentration in a spectrophotometer, and then, the degree of regeneration was calculated, according to Equation 9. (9) where m des is the amount of dye adsorbed in the desorption cycle (mg), and m ads is the amount of dye adsorbed in the adsorption cycle (mg).…”

“…The techniques commonly used for the treatment of wastewater to remove dyes are flocculation/coagulation, precipitation, photocatalytic degradation, biological oxidation, ion exchange, advanced oxidative processes, bioremediation, membrane separation, and adsorption [7,8]. The adsorption stands out due to its ease of operation and implementation, high removal rate, and low cost, depending on the adsorbent material used [9]. In this context, obtaining and producing effective and low-cost adsorbents are constant challenges because, in addition to the economic bias and adsorption capacity, the material must show chemical, mechanical stability, and potential for reuse [10].…”

Effect of calcination temperature on material from an ant colony (termite): searching for the characterization of new dye adsorbent materials

“…These low-cost materials require little processing or are abundant in nature. They include industry byproducts or waste materials, such as macaúba meal [8] and castor bean meal [9], waste from biodiesel production and agricultural solid waste, such as orange and uvaia seeds [10], soybean hull [11], cotton waste [12], coconut shell [13], sugarcane bagasse [14], sisal fiber [15], orange peel [15]. They also include natural materials represented by montmorillonite clay [16], bentonite [17], diatomite [18], perlite [19] and pyrophyllite [20].…”