SAMRC; Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, South Africa.
Applied and Environmental Microbiology Research Group (AEMREG), University of Fort Hare, Alice, South Africa.
Sci Rep. 2019 Jul 4;9(1):9672. doi: 10.1038/s41598-019-45293-x.
The continuous demand for clean and affordable water needed for the survival of man is now a major challenge globally. Therefore, the treatment of wastewater generated from printing, textile and dyeing industries containing soluble dyes like rhodamine B (Rh-B) is of utmost important. This study investigates the efficiency of new multifunctionalized superparamagnetic nanoparticles (MNP-Tppy) for the removal of cationic Rh-B from aqueous solution. To afford MNP-Tppy, the surface of MNP was covalently functionalized with terpyridine ligand to enable an anionic charge on the adsorbent. The results of characterization including Brunauer-Emmett-Teller (BET) analysis, thermal gravimetric analysis (TGA), vibrating sample magnetometer (VSM), scanning electron microscope (SEM) and fourier transform infra-red spectroscopy (FTIR) indicate that this superparamagnetic nanoparticle functionalized with multiple nitrogen atoms was successfully synthesized. Adsorption experiments involving the effect of pH, time, temperature, adsorbent dose and adsorbate concentration show that the maximum adsorption of Rh-B using MNP-Tppy was observed at pH 9 and removal was observed to increase as solution pH increases. Similarly, time variation shows that adsorbate removal increases as adsorption time increases until the removal attained equilibrium at 15 min. Kinetic studies conducted among four kinetic models using the data obtained from effect of time indicate that the adsorption process can best be described by the pseudo-second order model. Isotherm studies conducted at three different temperatures revealed that Langmuir isotherm model fitted well for the equilibrium data with q value of 113.64 mg g and thermodynamic studies showed that the adsorption process involving the removal of Rh-B from aqueous solution by MNP-Tppy is spontaneous, endothermic and realistic in nature. Lastly, Reusability experiments indicate that MNP-Tppy can be regenerated and re-used.
人类的生存需要清洁且负担得起的水，而这一持续需求目前在全球范围内构成了一项重大挑战。因此，处理来自印刷、纺织和染整行业的废水变得至关重要，因为这些废水中含有可溶染料，如罗丹明 B（Rh-B）。本研究调查了新型多功能超顺磁纳米粒子（MNP-Tppy）对从水溶液中去除阳离子 Rh-B 的效率。为了制备 MNP-Tppy，将 MNP 的表面通过共价键功能化，接上了三吡啶配体，使吸附剂带有负电荷。包括比表面积（BET）分析、热重分析（TGA）、振动样品磁强计（VSM）、扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）在内的表征结果表明，成功合成了这种带有多个氮原子的超顺磁纳米粒子。涉及 pH 值、时间、温度、吸附剂剂量和吸附质浓度等因素的吸附实验表明，使用 MNP-Tppy 吸附 Rh-B 的最大吸附量出现在 pH 9 时，且随着溶液 pH 值的增加，去除率也随之增加。同样，时间变化表明，随着吸附时间的增加，吸附质的去除率也会增加，直到 15 分钟时达到吸附平衡。通过时间效应获得的数据进行的四种动力学模型研究表明，吸附过程最符合准二级动力学模型。在三个不同温度下进行的等温线研究表明，Langmuir 等温线模型很好地拟合了平衡数据，q 值为 113.64 mg g，热力学研究表明，MNP-Tppy 从水溶液中去除 Rh-B 的吸附过程是自发的、吸热的和现实的。最后，可重复使用性实验表明，MNP-Tppy 可以被再生和重复使用。
