Faculty of Chemical and Petroleum Engineering, University of Tabriz, Tabriz 5166616471, Iran.
Faculty of Chemical and Petroleum Engineering, University of Tabriz, Tabriz 5166616471, Iran.
Int J Biol Macromol. 2024 Jan;254(Pt 1):127750. doi: 10.1016/j.ijbiomac.2023.127750. Epub 2023 Oct 29.
Existing Ni heavy metal ions in an aqueous medium are highly hazardous for living organisms and humans. Therefore, designing low-cost adsorbents with enhanced effectiveness is essential for removing nickel ions to safeguard public health. In this study, a novel green nanocomposite hydrogel was synthesized through the free radical solution and bulk polymerization method, and its capability to remove divalent nickel ions from aqueous media was examined. The bionanocomposite hydrogel named as SA-g-poly(AAm)/HL-CoFeO was produced by grafting polyacrylamide (AAm) onto sodium alginate (SA) in the presence of a magnetic composite recognized as HL-CoFeO, where HL represents hydrolyzed Luffa Cylindrica. By employing FT-IR, XRD, VSM, SEM, EDX-Map, BET, DLS, HPLC, and TGA techniques, morphological evaluation and characterization of the adsorbents were carried out. The performance of the adsorption process was studied under varying operational conditions including pH, temperature, contact duration, initial concentration of pollutant ions, and adsorbent dosage. HPLC analysis proved the non-toxic structure of the bionanocomposite hydrogel. The number of unreacted acrylamide monomers within the hydrogel matrix was measured at 20.82 mg/kg. The optimum conditions was discovered to be pH = 6, room temperature, adsorbent dosage of 1 of g.L, initial Ni concentration of 10 mg.L, and contact time of 100 min, and the maximum adsorption efficiency at optimal state was calculated as 70.09, 90.25, and 93.83 % for SA-g-poly (AAm), SA-g-poly(AAm)/HL, and SA-g-poly(AAm)/HL-CoFeO samples, respectively. Langmuir isotherm model was in good agreement with the experimental data and the maximum adsorption capacity of SA-g-poly(AAm), SA-g-poly(AAm)/HL, and SA-g-poly(AAm)/HL-CoFeO samples was calculated to be 31.37, 43.15, and 45.19 mg.g, respectively. The adsorption process, according to kinetic studies, follows a pseudo-second-order kinetic model. Investigations on thermodynamics also demonstrated that the process is exothermic and spontaneous. Exploring the interference effect of co-existing ions showed that the adsorption efficiency has decreased with concentration enhancement of Ca and Na cations in aqueous medium. Furthermore, the adsorption/desorption assessments revealed that after 8 consecutive cycles, there had been no noticeable decline in the adsorption effectiveness. Finally, actual wastewater treatment outcomes demonstrated that the bionanocomposite hydrogel successfully removes heavy metal pollutants from shipbuilding industry effluent. Therefore, the findings revealed that the newly fabricated bionanocomposite hydrogel is an efficient, cost-effective, easy-separable, and green adsorbent that could be potentially utilized to remove divalent nickel ions from wastewater.
存在于水介质中的镍等重金属离子对生物体和人类具有高度危害性。因此，设计具有增强效果的低成本吸附剂对于去除镍离子以保障公众健康至关重要。在本研究中，通过自由基溶液和本体聚合方法合成了一种新型绿色纳米复合水凝胶，并研究了其从水介质中去除二价镍离子的能力。该水凝胶名为 SA-g-poly(AAm)/HL-CoFeO，是通过在磁性复合 HL-CoFeO（HL 代表水解的丝瓜络）存在下将聚丙烯酰胺 (AAm) 接枝到海藻酸钠 (SA) 上制备的。通过使用 FT-IR、XRD、VSM、SEM、EDX-Map、BET、DLS、HPLC 和 TGA 技术对吸附剂进行了形态评估和表征。研究了在不同操作条件下（包括 pH 值、温度、接触时间、污染物初始浓度和吸附剂用量）吸附过程的性能。HPLC 分析证明了生物纳米复合水凝胶的无毒结构。水凝胶基质中未反应的丙烯酰胺单体数量为 20.82mg/kg。发现最佳条件为 pH=6、室温、吸附剂用量为 1g·L、初始 Ni 浓度为 10mg·L 和接触时间为 100min，在最佳状态下的最大吸附效率分别为 70.09%、90.25%和 93.83%。Langmuir 等温模型与实验数据吻合良好，SA-g-poly(AAm)、SA-g-poly(AAm)/HL 和 SA-g-poly(AAm)/HL-CoFeO 样品的最大吸附容量分别计算为 31.37、43.15 和 45.19mg·g。根据动力学研究，吸附过程遵循准二级动力学模型。热力学研究还表明该过程是放热和自发的。考察共存离子的干扰效应表明，随着水中 Ca 和 Na 阳离子浓度的增加，吸附效率有所下降。此外，吸附/解吸评估表明，经过 8 次连续循环后，吸附效率没有明显下降。最后，实际废水处理结果表明，生物纳米复合水凝胶能够从船舶制造工业废水中有效去除重金属污染物。因此，研究结果表明，新制备的生物纳米复合水凝胶是一种高效、经济高效、易于分离和绿色的吸附剂，可用于从废水中去除二价镍离子。
