In this study, new bio-based crogels as adsorbents were prepared from date palm tree waste (Phoenix dactylifera L). Cellulose nanofibrills (CNFs) and cellulose nanofibrills cryogels modified with 10 % GO and Fe₃O₄ nanoparticle as filler (CNFs/GO/Fe₃O₄) were prepared by facile freeze drying methodology. The unmodified and modified cryogels were characterized by fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), energy-dispersive X-ray spectroscopy (EDAX), specific surface area (BET), thermogravimetric analysis (TGA) and mechanical test. In the following, CNFs/GO/Fe₃O₄ cryogels were achieved with low density (0.0139 (g/cm³)), ultra-porosity (99.46 %), appropriate specific surface area (S_BET = 55 (m²/g)) with more significant thermal and mechanical properties than unmodified cryogel. Furthermore, the adsorptive removal of chromium (VI), lead (II) and mercury (II) ions was investigated by response surface methodology (RSM) with central composite design (CCD), on to CNFs/GO/Fe₃O₄ cryogels. Optimal conditions resulting from the effective parameters such as pH, adsorbent dosage and contact time were assessed via RSM for this novel adsorbent. The adsorption kinetics were fitted well with pseudo-second-order model and the adsorption capacity of Pb(II), Hg(II) and Cr(VI) on CNFs/GO/Fe₃O₄ cryogels by Langmuir model concluded 126.58, 36.70 and 73.52 mg/g, respectively at 298 $\pm 1°K$. In addition, CNFs/GO/Fe₃O₄ cryogels could be successfully reused even after four cycles.

在这项研究中，从枣椰树废料（Phoenix dactylifera L）中制备了新的生物基crogels作为吸附剂。采用快速冷冻干燥法制备了以10％GO和Fe ₃ O ₄纳米粒子为填充剂（CNFs / GO / Fe ₃ O ₄）修饰的纤维素纳米原纤（CNF）和纤维素纳米原纤。通过傅立叶变换红外光谱（FTIR），场发射扫描电子显微镜（FESEM），X射线衍射分析（XRD），能量色散X射线光谱（EDAX），比表面积（BET）对未修饰和修饰的冰晶进行了表征），热重分析（TGA）和机械测试。以下是CNF / GO / Fe ₃ O ₄与未改性的冷冻凝胶相比，低密度（0.0139（g / cm ³）），超孔隙度（99.46％），合适的比表面积（S _BET = 55（m ² / g））可获得冷冻凝胶。 。此外，通过响应表面方法（RSM）和中心复合设计（CCD），对CNFs / GO / Fe ₃ O _4进行了吸附去除铬（VI），铅（II）和汞（II）离子的研究。冰晶石。通过RSM评估了由有效参数（例如pH，吸附剂剂量和接触时间）产生的最佳条件。吸附动力学与拟二阶模型拟合得很好，Langmuir模型得出的Pb（II），Hg（II）和Cr（VI）在CNFs / GO / Fe ₃ O ₄低温凝胶上的吸附容量得出126.58、36.70和。 298时分别为73.52 mg / g$\pm \mathrm{1个}°ķ$。此外，即使经过四个循环，CNF / GO / Fe ₃ O ₄冷冻凝胶也可以成功地重复使用。