PDF(Pubmed)
Abstract：
In this study, RM (red mud) was acidified with sulfuric acid, and the acidified ARM (acidified red mud) was utilized as an innovative adsorption material for treating antibiotic-containing wastewater. The adsorption conditions, kinetics, isotherms, thermodynamics, and mechanism of ARM for CIP (ciprofloxacin) were investigated. The characterization of the ARM involved techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), X-ray fluorescence (XRF), thermogravimetric analysis (TGA), and NH3-TPD analysis. Adsorption studies employed a response surface methodology (RSM) for the experimental design. The results showed that ARM can absorb CIP effectively. The RSM optimal experiment indicated that the most significant model terms influencing adsorption capacity were solution pH, CIP initial concentration, and ARM dosage, under which the predicted maximum adsorption capacity achieved 7.30 mg/g. The adsorption kinetics adhered to a pseudo-second-order model, while equilibrium data fitted the Langmuir-Freundlich isotherm, yielding maximum capacity values of 7.35 mg/g. The adsorption process occurred spontaneously and absorbed heat, evidenced by ΔGθ values between -83.05 and -91.50 kJ/mol, ΔSθ at 281.6 J/mol/K, and ΔHθ at 0.86 kJ/mol. Analysis using attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) indicated a complex reaction between the Al-O in the ARM and the ester group -COO in CIP. The C=O bond in CIP was likely to undergo a slight electrostatic interaction or be bound to the internal spherical surface of the ARM. The findings indicate that ARM is a promising and efficient adsorbent for CIP removal from wastewater.
摘要：
在这项研究中,RM（红泥）用硫酸酸化，并将酸化的ARM（酸化的赤泥）用作处理含抗生素废水的创新吸附材料。吸附条件，动力学,等温线，热力学，并对环丙沙星对CIP（环丙沙星）的作用机制进行了研究。ARM的表征涉及扫描电子显微镜（SEM）等技术，透射电子显微镜（TEM），Brunauer-Emmett-Teller（BET），X射线衍射(XRD)X射线荧光(XRF),热重分析（TGA），和NH3-TPD分析。吸附研究采用响应面方法（RSM）进行实验设计。结果表明，ARM可以有效吸收CIP。RSM优化实验表明,影响吸附量最显著的模型项是溶液pH,CIP初始浓度，和ARM剂量，在此条件下，预测的最大吸附容量达到7.30mg/g。吸附动力学符合伪二阶模型，虽然平衡数据符合朗缪尔-弗洛伊德利希等温线，产量最大容量值为7.35毫克/克。吸附过程自发发生并吸收热量，由-83.05和-91.50kJ/mol之间的ΔGθ值证明，ΔSθ为281.6J/mol/K，和ΔHθ为0.86kJ/mol。使用衰减全反射傅里叶变换红外光谱（ATR-FTIR）的分析表明，ARM中的Al-O与酯基-COOinCIP之间存在复杂的反应。CIP中的C=O键可能会发生轻微的静电相互作用或与ARM的内部球形表面结合。研究结果表明，ARM是一种有前途的高效吸附剂，可用于去除废水中的CIP。
