Fu Jialin, Yap Jia Xin, Leo Choe Peng, Chang Chun Kiat
School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, Nibong Tebal, 14300 Penang, Malaysia.
School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, Nibong Tebal, 14300 Penang, Malaysia.
Int J Biol Macromol. 2023 Apr 15;234:123642. doi: 10.1016/j.ijbiomac.2023.123642. Epub 2023 Feb 13.
Although anionic polyelectrolyte hydrogel beads offer attractive adsorption of cationic dyes, phosphate adsorption is limited by electrostatic interactions. In this work, carboxymethyl cellulose (CMC)/sodium alginate (SA) hydrogel beads were modified with calcium carbonate (CaCO) and/or bentonite (Be). The compatibility between CaCO and Be was proven by the homogeneous surface, as shown in the scanning electron microscopic images. Fourier-transform infrared and X-ray diffraction spectra further confirmed the existence of inorganic filler in the hydrogel beads. Although CMC/SA/Be/CaCO hydrogel beads attained the highest methylene blue and phosphate adsorption capacities (142.15 MB mg/g, 90.31 P mg/g), phosphate adsorption was significantly improved once CaCO nanoparticles were incorporated into CMC/SA/CaCO hydrogel beads. The kinetics of MB adsorption by CMC/SA hydrogel beads with or without inorganic fillers could be described by the pseudo-second-order model under chemical interactions. The phosphate adsorption by CMC/SA/Be/CaCO hydrogel beads could be explained by the Elovich model due to heterogeneous properties. The incorporation of Be and CaCO also improved the phosphate adsorption through chemical interaction since Langmuir isotherm fitted the phosphate adsorption by CMC/SA/Be/CaCO hydrogel beads. Unlike MB adsorption, the reusability of these hydrogel beads in phosphate adsorption reduced slightly after 5 cycles.
尽管阴离子聚电解质水凝胶珠对阳离子染料具有良好的吸附性能，但磷酸盐的吸附受到静电相互作用的限制。在这项工作中，羧甲基纤维素（CMC）/海藻酸钠（SA）水凝胶珠用碳酸钙（CaCO₃）和/或膨润土（Be）进行了改性。扫描电子显微镜图像显示，CaCO₃和Be之间的相容性通过均匀的表面得以证明。傅里叶变换红外光谱和X射线衍射光谱进一步证实了水凝胶珠中无机填料的存在。尽管CMC/SA/Be/CaCO₃水凝胶珠具有最高的亚甲基蓝和磷酸盐吸附容量（142.15 MB mg/g，90.31 P mg/g），但一旦将CaCO₃纳米颗粒掺入CMC/SA/CaCO₃水凝胶珠中，磷酸盐吸附就会显著改善。在化学相互作用下，有无无机填料的CMC/SA水凝胶珠对MB的吸附动力学可用准二级模型描述。由于性质不均一，CMC/SA/Be/CaCO₃水凝胶珠对磷酸盐的吸附可用埃洛维奇模型解释。由于朗缪尔等温线适用于CMC/SA/Be/CaCO₃水凝胶珠对磷酸盐的吸附，Be和CaCO₃的掺入也通过化学相互作用改善了磷酸盐吸附。与MB吸附不同，这些水凝胶珠在磷酸盐吸附中的可重复使用性在5个循环后略有下降。
