摘要
In this study, the responsiveness of Na + , Mg 2+ , Ca 2+ and Al 3+ to sodium alginate (SA) and their influence on kaolinite dispersion/flocculation behavior were investigated through rheology and turbidity tests. The effects of metal ions on the interaction between SA and kaolinite were analyzed by zeta potential, fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT). The results showed that Na + and Mg 2+ resulted in a decreasing of the viscosity and modulus of SA solution for they have the electrostatic shielding effect on SA. Ca 2+ and Al 3+ significantly increased the viscosity and modulus of SA solution because Ca 2+ and Al 3+ not only have the electrostatic shielding effect on SA but also could form the different network structure complexes. The order of the responsiveness of metal ions and SA sorted by intensity level was: Al 3+ > Ca 2+ >Mg 2+ > Na + . SA has a dispersion effect on kaolinite particles under the background of Na + and Mg 2+ , and SA has a flocculation effect on kaolinite particles in the presence of Ca 2+ and Al 3+ . The flocculation efficiency of SA on kaolinite suspension containing Al 3+ was much higher than that of SA on kaolinite suspension in the presence of Ca 2+ . Zeta potential and FTIR results showed that SA could be adsorbed on the kaolinite surface through electrostatic force and hydrogen bond in the presence of Na + and Mg 2+ . Microscope observation , XPS and DFT results showed SA could not only form chemical adsorption with Ca 2+ /Al 3+ on the kaolinite surface but also be cross-linked with Ca 2+ /Al 3+ to form a network structure, which could sweep and trap kaolinite particles in suspension. This work has strategic significance for the responsiveness of natural polysaccharide to metal ions and their application in environmental protection of mine wastewater, as well as the clean and circular utilization of water.
危险品化学品经营许可证（带存储）