Nanoplastics, a kind of emerging pollutant in natural environments, have now drawn tremendous attention worldwide. Flocculation with Mg/Al-layered double hydroxides (LDH) precursor solutions has showed great potential for removing negatively charged nanoparticles from water. In this study, the flocculation behavior and mechanism for the removal of polystyrene nanoplastics (PSNP) with Mg/Al flocs or Mg/Al LDH were systematically analyzed and investigated. During the process of flocculation, it was observed that in situ Mg/Al LDH can be gradually formed with increasing pH, in addition, PSNP were captured or attached to the surface of LDH with a turning point around pH of 5.0. In acidic solutions with pH < 5.0, the negative surface charges of PSNP were diminished mainly due to the high concentrations of hydrogen ions and the positive charges from Mg and Al ions. In a moderately alkaline solution, Mg and Al ions gradually formed crystals capturing PSNP. Electrostatic adsorption and intermolecular force are the main mechanisms via which PSNP are captured on Mg/Al flocs. Herein, PSNP removal efficiencies from water were more than 90.0%. As the problem of plastic pollution becomes more severe, in situ LDH growth flocculation can provide an efficient way for the removal of PSNP.

纳米塑料是自然环境中一种新兴的污染物，如今已​​引起全世界的广泛关注。用Mg / Al层状双氢氧化物（LDH）前驱体溶液进行絮凝已显示出从水中去除带负电荷的纳米粒子的巨大潜力。在这项研究中，系统地分析和研究了Mg / Al絮凝物或Mg / Al LDH去除聚苯乙烯纳米塑料（PSNP）的絮凝行为和机理。在絮凝过程中，观察到随着pH的升高，原位的Mg / Al LDH可以逐渐形成，此外，PSNP被捕获或附着在LDH的表面上，其转折点的pH值约为5.0。在pH <5.0的酸性溶液中，PSNP的负表面电荷减少的主要原因是高浓度的氢离子以及Mg和Al离子的正电荷。在中等碱性的溶液中，Mg和Al离子逐渐形成捕获PSNP的晶体。静电吸附和分子间作用力是将PSNP捕获在Mg / Al絮凝物上的主要机理。在此，从水中去除PSNP的效率大于90.0％。随着塑料污染问题变得更加严重，原位LDH生长絮凝可以提供一种去除PSNP的有效方法。从水中去除PSNP的效率超过90.0％。随着塑料污染问题变得更加严重，原位LDH生长絮凝可以提供一种去除PSNP的有效方法。从水中去除PSNP的效率超过90.0％。随着塑料污染问题变得更加严重，原位LDH生长絮凝可以提供一种去除PSNP的有效方法。