As the single largest chlorine source of plastics, hazardous polyvinyl chloride (PVC) has become an increasing environmental concern with the rapid microplastics accumulation. An advanced separation method is advocated to purify waste PVC plastics, optimize physical recycling, and protect aquatic and terrestrial environment safety. In this study, we proposed a novel scheme for the flotation separation of PVC plastics with diverse plasticizer contents (PVCs) via regulating hydrophilicity based on a selective ferric deposition. Rigid PVCs were prone to loading ferric ions and generating hydrophilic shells than flexible PVCs. Plasticizers can diffuse freely through the interior and surface of PVC plastics. Abundant plasticizers thereby overlaid the surface of flexible PVC and shielded PVC matrix from ferric ions. By regulating the ferric concentration, the wettability of PVCs was adjusted to separate rigid and flexible PVCs by froth flotation. Waste PVCs could also be separated from each other through the compound process of ferric deposition and flotation, further confirming its feasibility and stability. Thus far, this study supplies distinctive insights into the wettability regulation of plasticizer-doping PVC surfaces, contributes a pioneering hydrophilization method to PVCs separation and recycling, and mitigates hazardous PVC microplastics by source control.

作为塑料中最大的单一氯源，有害的聚氯乙烯 (PVC) 随着微塑料的快速积累，已成为日益严重的环境问题。提倡采用先进的分离方法净化废旧PVC塑料，优化物理回收，保护水陆环境安全。在这项研究中，我们提出了一种通过基于选择性铁沉积调节亲水性来浮选分离具有不同增塑剂含量 (PVC) 的 PVC 塑料的新方案。与柔性 PVC 相比，刚性 PVC 更容易加载三价铁离子并产生亲水壳。增塑剂可以通过 PVC 塑料的内部和表面自由扩散。丰富的增塑剂因此覆盖了柔性 PVC 和屏蔽 PVC 基质的表面，使其免受铁离子的影响。通过调节铁浓度，调节 PVC 的润湿性，通过泡沫浮选分离刚性和柔性 PVC。废聚氯乙烯还可以通过铁沉积和浮选的复合工艺相互分离，进一步证实了其可行性和稳定性。迄今为止，这项研究为掺有增塑剂的 PVC 表面的润湿性调节提供了独特的见解，为 PVC 的分离和回收提供了一种开创性的亲水化方法，并通过源头控制减少了有害的 PVC 微塑料。