College of Mechanical and Electrical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071, China.
College of Mechanical and Electrical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071, China; Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071, China.
J Colloid Interface Sci. 2022 Apr;611:629-643. doi: 10.1016/j.jcis.2021.12.115. Epub 2021 Dec 23.
The phenomenon that calcium alginate does not exhibit high adsorption capacity as a carrier material has not been reasonably explained or solved. In this paper, a new viewpoint that the orbital energy level of metal ions and the binding degree of the α-l-guluronate and β-d-mannuronate units affect the adsorption performance of the composite was innovatively proposed. Taking barium alginate (BA) as an example, the possibility of replacing calcium alginate is discussed. Barium alginate/graphene oxide (BA/GO) membranes and three-dimensional (3D) barium alginate-bentonite-graphene oxide derived (3D-BA) hydrogels were prepared by vacuum freeze-drying to remove methylene blue. The structure and morphology of the prepared adsorbents were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry and Fourier transform infrared spectroscopy. The effects of adsorbent dosage, doping ratio, temperature, contact time, pH value and initial dye concentration on the adsorption performance of BA composites were investigated. The adsorption capacities of the BA/GO and 3D-BA materials were 1011.3 and 710.3 mg/g, respectively. The BA/GO membrane exhibited stable filtration performance against high concentrations of dyes. Benefiting from the strong interaction between bentonite, sodium alginate and Ba, the 3D-BA hydrogel showed higher thermal stability and better adsorption efficiency than other materials. The Elovich kinetic model and Sips equation can appropriately describe the adsorption process. The results show that barium alginate is a better carrier material than calcium alginate.
海藻酸钙作为载体材料不表现出高吸附能力的现象尚未得到合理的解释或解决。本文创新性地提出了一种新观点，即金属离子的轨道能级和α-L-古洛糖醛酸和β-D-甘露糖醛酸单元的结合程度影响复合材料的吸附性能。以海藻酸钠（BA）为例，讨论了替代海藻酸钙的可能性。通过真空冷冻干燥去除亚甲基蓝，制备了海藻酸钠/氧化石墨烯（BA/GO）膜和三维（3D）海藻酸钠-膨润土-氧化石墨烯衍生（3D-BA）水凝胶。通过扫描电子显微镜、X 射线光电子能谱、热重分析和傅里叶变换红外光谱对制备的吸附剂的结构和形态进行了表征。考察了吸附剂用量、掺杂比、温度、接触时间、pH 值和初始染料浓度对 BA 复合材料吸附性能的影响。BA/GO 和 3D-BA 材料的吸附容量分别为 1011.3 和 710.3 mg/g。BA/GO 膜对高浓度染料表现出稳定的过滤性能。得益于膨润土、海藻酸钠和 Ba 之间的强相互作用，3D-BA 水凝胶表现出比其他材料更高的热稳定性和更好的吸附效率。Elovich 动力学模型和 Sips 方程可以较好地描述吸附过程。结果表明，海藻酸钡是一种比海藻酸钙更好的载体材料。
