Radwan Emad K, Omar Rehab A, El-Wakeel Shaimaa T
Water Pollution Research Department, National Research Centre, 33 El Buhouth St, Dokki, 12622 Giza, Egypt.
Water Pollution Research Department, National Research Centre, 33 El Buhouth St, Dokki, 12622 Giza, Egypt.
Int J Biol Macromol. 2025 Jul;318(Pt 4):145271. doi: 10.1016/j.ijbiomac.2025.145271. Epub 2025 Jun 16.
In this study, alginate aerogel beads crosslinked with calcium, cobalt, and zinc were synthesized via ionotropic gelation followed by freeze-drying. Their properties were analyzed using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), attenuated total reflection Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and nitrogen adsorption. EDX and XPS confirmed the presence and uniform distribution of carbon, oxygen, and the respective crosslinking metals without detectable impurities. Ca-alginate was semi-crystalline while crosslinking with Zn and Co decreased the crystallinity. Co-alginate aerogel beads exhibited the highest swelling, surface area, and pore volume. A comprehensive evaluation of the adsorption performance of the different prepared alginate aerogel beads was conducted for the simultaneous removal of basic red 18 (BR18) dye and copper ions (Cu) from wastewater, encompassing adsorption kinetics, isotherms, competitive adsorption, and thermodynamics. Among the prepared aerogels, Co-alginate exhibited the highest adsorption efficiency, achieving maximum removal efficiencies of 62 % for BR18 dye and 97 % for Cu within 30 min at initial pH (pH) 6 and room temperature, using a dosage of 1 g/L. Adsorption followed a pseudo-first-order kinetic model, indicating a diffusion-controlled physisorption, while equilibrium data aligned with the Freundlich isotherm, suggesting a heterogeneous surface. The Langmuir adsorption capacity for Cu was 128 mg/g (single component) and 163 mg/g (binary components), surpassing many reported adsorbents. Competitive adsorption studies revealed that Cu was preferentially adsorbed at lower concentrations, and increasing BR18 dye concentration reduced competition effects. Thermodynamic analysis confirmed that Cu adsorption was endothermic, while BR18 dye adsorption was exothermic. The findings highlighted the potential of Co-alginate aerogel beads as an efficient adsorbent for treating textile wastewater.
在本研究中，通过离子交联凝胶化法，随后进行冷冻干燥，合成了与钙、钴和锌交联的海藻酸钠气凝胶珠。使用扫描电子显微镜（SEM）、能量色散X射线光谱仪（EDX）、衰减全反射傅里叶变换红外光谱仪（ATR-FTIR）、X射线衍射仪（XRD）、X射线光电子能谱仪（XPS）和氮吸附仪对其性能进行了分析。EDX和XPS证实了碳、氧以及各自交联金属的存在和均匀分布，且未检测到杂质。钙海藻酸盐是半结晶的，而与锌和钴交联会降低结晶度。钴海藻酸钠气凝胶珠表现出最高的溶胀度、表面积和孔体积。对不同制备的海藻酸钠气凝胶珠的吸附性能进行了综合评估，以同时去除废水中的碱性红18（BR18）染料和铜离子（Cu），包括吸附动力学、等温线、竞争吸附和热力学。在所制备的气凝胶中，钴海藻酸钠表现出最高的吸附效率，在初始pH值为6和室温下，使用剂量为1 g/L时，在30分钟内对BR18染料的最大去除效率达到62%，对铜的最大去除效率达到97%。吸附遵循准一级动力学模型，表明是扩散控制的物理吸附，而平衡数据符合弗伦德里希等温线，表明表面不均匀。铜的朗缪尔吸附容量为128 mg/g（单一组分）和163 mg/g（二元组分），超过了许多已报道的吸附剂。竞争吸附研究表明，在较低浓度下铜优先被吸附，并且增加BR18染料浓度会降低竞争效应。热力学分析证实，铜的吸附是吸热的，而BR18染料的吸附是放热的。研究结果突出了钴海藻酸钠气凝胶珠作为处理纺织废水的高效吸附剂的潜力。
