Hessien Manal
Department of Chemistry, College of Science, King Faisal University, P.O. Box 400, Alahsa 31982, Saudi Arabia.
Molecules. 2023 Jun 2;28(11):4526. doi: 10.3390/molecules28114526.
The toxicity of dyes has a long-lasting negative impact on aquatic life. Adsorption is an inexpensive, simple, and straightforward technique for eliminating pollutants. One of the challenges facing adsorption is that it is hard to collect the adsorbents after the adsorption. Adding a magnetic property to the adsorbents makes it easier to collect the adsorbents. The current work reports the synthesis of an iron oxide-hydrochar composite (FHC) and an iron oxide-activated hydrochar composite (FAC) through the microwave-assisted hydrothermal carbonization (MHC) technique, which is known as a timesaving and energy-efficient method. The synthesized composites were characterized using various techniques, such as FT-IR, XRD, SEM, TEM, and N isotherm. The prepared composites were applied in the adsorption of cationic methylene blue dye (MB). The composites were formed of crystalline iron oxide and amorphous hydrochar, with a porous structure for the hydrochar and a rod-like structure for the iron oxide. The pH of the point of zero charge (pHpzc) of the iron oxide-hydrochar composite and the iron oxide-activated hydrochar composite were 5.3 and 5.6, respectively. Approximately 556 mg and 50 mg of MB dye was adsorbed on the surface of 1 g of the FHC and FAC, respectively, according to the maximum adsorption capacity calculated using the Langmuir model.
染料的毒性对水生生物有着持久的负面影响。吸附是一种用于去除污染物的廉价、简单且直接的技术。吸附面临的挑战之一是吸附后难以收集吸附剂。给吸附剂添加磁性使其更易于收集。当前工作报道了通过微波辅助水热碳化（MHC）技术合成氧化铁-水炭复合材料（FHC）和氧化铁-活化水炭复合材料（FAC），该技术是一种省时且节能的方法。使用多种技术对合成的复合材料进行了表征，如傅里叶变换红外光谱（FT-IR）、X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和N等温线。将制备的复合材料应用于阳离子亚甲基蓝染料（MB）的吸附。复合材料由结晶氧化铁和无定形水炭组成，水炭具有多孔结构，氧化铁具有棒状结构。氧化铁-水炭复合材料和氧化铁-活化水炭复合材料的零电荷点pH（pHpzc）分别为5.3和5.6。根据使用朗缪尔模型计算的最大吸附容量，1 g FHC和FAC表面分别吸附了约556 mg和50 mg的MB染料。
