Abstract

Biomass waste (Chinese traditional medicine residues) is one of the most promising sources of biochar. Here, the present study illustrated the activated biochar (BC_A) was prepared using the herb residue (Astragalus membranaceus) via sodium carbonate (Na₂CO₃) activation for the removal of Cefradine (CF) in wastewater. The adsorbents were characterized by scanning electron microscopy, N₂ adsorption-desorption analysis, Fourier transform infrared spectrum, X-ray diffraction, X-ray photoelectron spectroscopy and zeta potential analysis. The effects of initial pH value, BC_A dosage, initial CF concentration and coexisting ion for CF removal were investigated. BC_A showed much higher absorption capacity for CF (q_m=64.76 mg/g) than the pristine biochar (BC). The uptake capacity of BC_A and BC for CF was found to be pH-dependent. The analysis of the kinetic and isotherm studies indicated that strong chemical-sorption interactions occurred on the surface of BC_A. The removal mechanisms of CF onto BC_A would include π-π EDA interaction, hydrogen bonding, ion exchange and electrostatic adsorption. In addition, the fixed bed experiments demonstrated that BC_A could be a promising and highly effective adsorbent to treat large volume of CF-contaminated wastewater.

摘要

生物质废弃物（中药渣）是最有前景的生物炭来源之一。在这里，本研究说明了使用药草残留物（黄芪）通过碳酸钠 (Na ₂ CO ₃ ) 活化制备活性生物炭 (BC _A )以去除废水中的头孢拉定 (CF)。通过扫描电子显微镜、N ₂吸附-解吸分析、傅里叶变换红外光谱、X 射线衍射、X 射线光电子能谱和zeta 电位分析对吸附剂进行了表征。研究了初始 pH 值、BC _A用量、初始 CF 浓度和共存离子对 CF 去除的影响。BC _A与原始生物炭 (BC) 相比，CF 显示出更高的吸收能力（q _m = 64.76 mg/g）。发现BC _A和BC 对CF的吸收能力依赖于pH。动力学和等温线研究的分析表明，BC _A表面发生了强烈的化学吸附相互作用。CF 在_{B A}上的去除机制包括 π-π EDA 相互作用、氢键、离子交换和静电吸附。此外，固定床实验表明，BC _A可能是一种有前途且高效的吸附剂，可用于处理大量 CF 污染的废水。