School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou, Zhejiang, China.
Key Laboratory of Recycling and Eco-Treatment of Waste Biomass of Zhejiang Province, Zhejiang University of Science and Technology, Hangzhou, Zhejiang, China.
PLoS One. 2021 Jul 14;16(7):e0254637. doi: 10.1371/journal.pone.0254637. eCollection 2021.
The primary purpose of this study is to eliminate Basic Red 46 dye from aqueous solutions utilizing batch experiments by adsorption on biochars prepared from bamboo and rice straw biomass. Biochars prepared from bamboo (B), and rice straw (R) was pyrolyzed at 500°C (B500 and R500). Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) Spectroscopy, X-ray Diffraction (XRD), and surface area and porosity analyzers were used to characterize the B500 and R500 samples. The characterization results indicated that the biochars possessed an amorphous porous structure with many functional groups consisting primarily of silicates. The adsorption rate of BR46 was evaluated using two kinetic models (pseudo-first-order and pseudo-second-order), and the results indicated that the pseudo-second-order model fitted to the experimental data well (R2>0.99). Nearly 24 h was sufficient to achieve equilibrium with the dye adsorption for the two biochars. R500 had a greater adsorption efficiency than B500. As pH levels increased, the dye's adsorption capability increased as well. The Langmuir and Freundlich isotherm models were used to investigate the equilibrium behavior of BR46 adsorption, and the equilibrium data fitted well with the Langmuir model (R2>0.99) compared to the Freundlich model (R2>0.89). The maximum adsorption capacities of BR46 are 9.06 mg/g for B500 and 22.12 mg/g for R500, respectively. Additionally, adsorption capacity increased as temperature increased, indicating that adsorption is favored at higher temperatures. The electrostatic interaction is shown to be the dominant mechanism of BR46 adsorption, and BR46 acts as an electron-acceptor, contributing to n-π EDA (Electron Donor-Acceptor) interaction. Thermodynamic parameters for the dye-adsorbent system revealed that the adsorption process is spontaneous and feasible. The values of the adsorption coefficient (Kd) were on the order of 102-103. Kd of R500 was greater than that of B500, indicating that R500 had a greater adsorption capacity. The results showed that R500 could be used as a low-cost alternative adsorbent for removing BR46 from effluents.
本研究的主要目的是通过吸附在由竹和稻草生物质制备的生物炭上来从水溶液中去除基本红 46 染料。由竹（B）和稻草（R）制备的生物炭在 500°C 下热解（B500 和 R500）。扫描电子显微镜（SEM）、傅里叶变换红外（FTIR）光谱、X 射线衍射（XRD）和表面积和孔隙率分析仪用于表征 B500 和 R500 样品。表征结果表明，生物炭具有无定形多孔结构，具有许多主要由硅酸盐组成的官能团。使用两种动力学模型（准一级和准二级）评估了 BR46 的吸附率，结果表明准二级模型很好地拟合了实验数据（R2>0.99）。两种生物炭的吸附平衡在近 24 小时内即可达到。R500 的吸附效率高于 B500。随着 pH 值的升高，染料的吸附能力也随之增加。Langmuir 和 Freundlich 等温线模型用于研究 BR46 吸附的平衡行为，与 Freundlich 模型（R2>0.89）相比，平衡数据更符合 Langmuir 模型（R2>0.99）。BR46 的最大吸附容量分别为 B500 上的 9.06mg/g 和 R500 上的 22.12mg/g。此外，吸附容量随温度升高而增加，表明吸附在较高温度下更有利。静电相互作用被证明是 BR46 吸附的主要机制，BR46 充当电子受体，有助于 n-π EDA（电子供体-受体）相互作用。染料-吸附剂系统的热力学参数表明吸附过程是自发和可行的。吸附系数（Kd）的值在 102-103 之间。R500 的 Kd 值大于 B500 的 Kd 值，表明 R500 的吸附容量更大。结果表明，R500 可用作从废水中去除 BR46 的低成本替代吸附剂。
