College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an 271018, Shandong, China.
Ji'nan Academy of Agricultural Sciences, Ji'nan 250316, Shandong, China.
Int J Mol Sci. 2019 Apr 10;20(7):1775. doi: 10.3390/ijms20071775.
In this study, a surface chemical-modified rice husk biochar with abundant amino groups and disulfide bonds for the removal of cadmium was prepared using cystamine dihydrochloride as a modification ligand and glutaraldehyde as a crosslinker. The biochars were characterized by Fourier transform infrared spectrometry (FTIR), elemental analysis, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), thermogravimetry analysis (TGA), and nitrogen sorption (BET) before and after modification. The adsorption properties of the modified biochars for Cd (II) were investigated in detail via adsorption isotherm models, adsorption kinetics models, and selective adsorption experiments. The surfaces of the cystamine-modified biochars with granular nanopolymers of sufficient functional groups of primary amine and disulfide linkage rendered the biochar surface more conducive to electrostatic attraction and surface complexation. The theoretical maximum adsorption capacity of the modified biochars (81.02 mg g) was almost 10-fold greater than that of the raw biochars (8.347 mg g) for Cd (II). Besides, the cystamine-modified biochars had a better affinity for Cd (II) compared to other heavy metals (Zn, As, Cd, Co, Ni, Cr), showing six-fold greater affinity for Cd (II) than Zn. The results of this study indicate that the modification of biochars derived from rice husks shows great potential in the removal of Cd (II) from contaminated water.
在这项研究中，使用胱胺二盐酸盐作为修饰配体，戊二醛作为交联剂，制备了一种表面化学修饰的富含氨基和二硫键的稻壳生物炭，用于去除镉。生物炭在修饰前后通过傅里叶变换红外光谱（FTIR）、元素分析、扫描电子显微镜（SEM）、X 射线光电子能谱（XPS）、热重分析（TGA）和氮气吸附（BET）进行了表征。通过吸附等温线模型、吸附动力学模型和选择性吸附实验详细研究了改性生物炭对 Cd（II）的吸附性能。具有足够数量的伯胺和二硫键官能团的颗粒纳米聚合物的胱胺修饰生物炭的表面使生物炭表面更有利于静电吸引和表面络合。改性生物炭的理论最大吸附容量（81.02 mg g）几乎是原始生物炭（8.347 mg g）的 10 倍，用于 Cd（II）。此外，与其他重金属（Zn、As、Cd、Co、Ni、Cr）相比，胱胺修饰的生物炭对 Cd（II）具有更好的亲和力，对 Cd（II）的亲和力是 Zn 的六倍。这项研究的结果表明，从稻壳中衍生的生物炭的修饰在去除受污染水中的 Cd（II）方面具有很大的潜力。
