Preparation and Adsorption Properties of Soybean Dreg/Hydrocalumite Composites

Abstract

The application of biomass-based composites in the field of adsorption has attracted extensive attention. Herein, soybean dreg/hydrocalumite composites were prepared by in situ self-assembly from soybean dregs and applied to the adsorption of Congo Red (CR). The composites were characterized by scanning electron microscopy, X-ray diffraction, Fourier infrared spectroscopy, and N2 physical adsorption–desorption. The results showed that the adsorption property of soybean dregs/hydrocalumite for CR was better than that of soybean dregs or hydrocalumite. Effects of preparation and adsorption conditions on the adsorption of CR by soybean dregs/hydrocalumite were also investigated. The removal rate of soybean dregs/hydrocalumite (30%BD-LDH) prepared under the optimized conditions reached 97.4% with a 486.8 mg·g–1 adsorption capacity. Also, the adsorption capacity of 30%BD-LDH was about 2.4 times and 3.0 times that of hydrocalumite and soybean dregs, respectively. In addition, the adsorption process of CR by 30%BD-LDH was more in line with the pseudo-second-order kinetic and Langmuir isothermal models.

Bean Dreg–Hydrocalumite Composite as a Highly Efficient Thermal Stabilizer for Poly(vinyl chloride)

“…The peaks at 29.4, 35.9, 46.7, and 49.9° indicated that there was a small amount of CaCO 3 in LDH and 5% BD–LDH2. 5 , 19 , 21 However, the crystal surface of cellulose was not obvious in the spectrum of 5% BD–LDH2, which was mainly due to the low content and uniform dispersion of BD. Compared with LDH, the characteristic diffraction peak intensity of the LDH phase in 5% BD–LDH2 was greatly weakened, which might be due to the reduction particle size or crystallinity of the LDH sheet in 5% BD–LDH2.…”

“…Compared with LDH, the characteristic diffraction peak intensity of the LDH phase in 5% BD–LDH2 was greatly weakened, which might be due to the reduction particle size or crystallinity of the LDH sheet in 5% BD–LDH2. 21 …”

“…The reason might be that the polymerization degree of BD was reduced hydrolysis during the preparation of 5% BD–LDH2. 21 Also, the LDH flakes were closely combined with BD and evenly deposited on the surface so as to inhibit the agglomeration of LDH. 19 It was feasible to improve the dispersion of 5% BD–LDH2 in PVC so as to improve its thermal stability to PVC.…”

“…According to the SEM characterization result ( Figure 2 ), adding an appropriate amount of BD to the reaction solution for preparing LDH can reduce the size of LDH flakes and prevent agglomeration, which is conducive to improve its dispersion and thermal stability to PVC. 21 …”

“…In the previous research, it was found that the crystal size, specific surface area, and adsorption performance of bean dreg (BD)–hydrocalumite composites were better than those of traditional hydrocalumite. 21 In order to further improve the property of hydrocalumite as a thermal stabilizer of PVC, a BD–hydrocalumite composite was prepared by the hydrothermal method with BD, Ca(OH) 2 , Al(OH) 3 , and Na 2 CO 3 as raw materials and applied to the thermal stabilizer of PVC. It provides a feasible method for the development of a hydrotalcite-like composite as a thermal stabilizer for PVC.…”