Department of Sanitary and Environmental Engineering, Rio de Janeiro State University, Rio de Janeiro, Brazil.
Environ Sci Pollut Res Int. 2024 Sep;31(43):55280-55300. doi: 10.1007/s11356-024-34797-3. Epub 2024 Sep 3.
The present study describes a set of methodological procedures (seldom applied together), including (i) development of an alternative adsorbent derived from abundant low-cost plant biomass; (ii) use of simple low-cost biomass modification techniques based on physical processing and chemical activation; (iii) design of experiments (DoE) applied to optimize the removal of a pharmaceutical contaminant from water; (iv) at environmentally relevant concentrations, (v) that due to initial low concentrations required determination by ultra-performance liquid phase chromatography coupled to mass spectrometry (UPLC-MS/MS). A central composite rotational design (CCRD) was employed to investigate the performance of vegetable sponge biomass (Luffa cylindrica), physically processed (crushing and sieving) and chemically activated with phosphoric acid, in the adsorption of the antibiotic trimethoprim (TMP) from water. The optimized model identified pH as the most significant variable, with maximum drug removal (91.1 ± 5.7%) achieved at pH 7.5, a temperature of 22.5 °C, and an adsorbent/adsorbate ratio of 18.6 mg µg. The adsorption mechanisms and surface properties of the adsorbent were examined through characterization techniques such as scanning electron microscopy (SEM), point of zero charge (pH) measurement, thermogravimetric analysis (TGA), specific surface area, and Fourier-transform infrared spectroscopy (FTIR). The best kinetic fit was obtained by the Avrami fractional-order model. The hypothesis of a hybrid behavior of the adsorbent was suggested by the equilibrium results presented by the Langmuir and Freundlich models and reinforced by the Redlich-Peterson model, which achieved the best fit (R = 0.982). The thermodynamic study indicated an exothermic, spontaneous, and favorable process. The maximum adsorption capacity of the material was 2.32 × 10 µg g at an equilibrium time of 120 min. Finally, a sustainable and promising adsorbent for the polishing of aqueous matrices contaminated by contaminants of emerging concern (CECs) at environmentally relevant concentrations is available for future investigations.
本研究描述了一组方法学程序（很少一起应用），包括：（i）开发源自丰富的低成本植物生物质的替代吸附剂；（ii）使用基于物理处理和化学活化的简单低成本生物质改性技术；（iii）设计实验（DoE）以优化从水中去除一种药物污染物；（iv）在环境相关浓度下，（v）由于初始浓度较低，需要通过超高效液相色谱-质谱联用（UPLC-MS/MS）进行测定。采用中心复合旋转设计（CCRD）研究了经过物理处理（粉碎和筛分）和磷酸化学活化的丝瓜瓤生物质（Luffa cylindrica）在水中吸附抗生素甲氧苄啶（TMP）的性能。优化模型确定 pH 为最显著变量，在 pH 7.5、温度为 22.5°C 和吸附剂/吸附物比为 18.6 mg µg 时，药物去除率达到最大值（91.1±5.7%）。通过扫描电子显微镜（SEM）、零电荷点（pH）测量、热重分析（TGA）、比表面积和傅里叶变换红外光谱（FTIR）等表征技术研究了吸附剂的吸附机制和表面性质。Avrami 分数阶模型得到了最佳的动力学拟合。Langmuir 和 Freundlich 模型呈现的平衡结果以及 Redlich-Peterson 模型均表明吸附剂的混合行为假设，该模型拟合效果最佳（R=0.982）。热力学研究表明该过程是放热、自发和有利的。在 120 分钟的平衡时间内，该材料的最大吸附容量为 2.32×10 µg g。最后，为未来的研究提供了一种可持续且有前途的用于环境相关浓度下受新兴关注污染物（CECs）污染的水基质抛光的吸附剂。
