Abstract
Soybean dreg is a by-product of soybean products production, with a large consumption in China. Low utilization value leads to random discarding, which is one of the important sources of urban pollution. In this work, porous biochar was synthesized using a one-pot method and potassium bicarbonate (KHCO3) with low-cost soybean dreg (SD) powder as the carbon precursor to investigating the adsorption of methylene blue (MB). The prepared samples were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analyzer (EA), Brunauer-Emmett-Teller (BET), X-ray diffractometer (XRD), Raman spectroscopy (Raman), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). The obtained SDB-K-3 showed a high specific surface area of 1620 m2 g−1, a large pore volume of 0.7509 cm3 g−1, and an average pore diameter of 1.859 nm. The results indicated that the maximum adsorption capacity of SDB-K-3 to MB could reach 1273.51 mg g−1 at 318 K. The kinetic data were most consistent with the pseudo-second-order model and the adsorption behavior was more suitable for the Langmuir isotherm equation. This study demonstrated that the porous biochar adsorbent can be prepared from soybean dreg by high value utilization, and it could hold significant potential for dye wastewater treatment in the future.
Highlights
The increasing demand for dyes in different industries exacerbates the discharge of dye wastewater [1], as well as their toxic effect on the environment and organisms, inducing significant concern from society as a whole [2]
After hightemperature activation with KHCO3, an abundance of pore structures was evident on the surface of the SDB-K-X, showing a 3D framework with randomly opened pores, indicating that KHCO3 played a positive role in the pore formation of biochar
The results indicated the adsorption process of SDB-K-3 on methylene blue (MB) occurred in a single layer
Summary
The increasing demand for dyes in different industries exacerbates the discharge of dye wastewater [1], as well as their toxic effect on the environment and organisms, inducing significant concern from society as a whole [2]. The effective removal of dye from wastewater and preventing it from polluting the environment is a significant challenge for industrial production that requires an urgent solution. Conventional dye removal methods that include biological, chemical, and physical approaches are used for the treatment of dye wastewater [12], such as biodegradation [13], membrane separation [14], coagulation and flocculation [15], photocatalytic degradation [16], and adsorption [17]. A large number of biomass waste products, such as pineapple crown leaves [18], wood chips [19], bamboo [20], walnut shells [21], bagasse [22], and orange peel [23] are used as raw ingredients in preparing carbon materials that can absorb dye wastewater
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
