Journal of Hazardous Materials 321 (2017) 193–202 Contents lists available at ScienceDirect Journal of Hazardous Materials journal homepage: www.elsevier.com/locate/jhazmat Development of hydrophobicity and selective separation of hazardous chlorinated plastics by mild heat treatment after PAC coating and froth flotation Nguyen Thi Thanh Truc, Chi-Hyeon Lee, Byeong-Kyu Lee (Professor) ∗ , Srinivasa Reddy Mallampati Department of Civil and Environmental Engineering, University of Ulsan, Daehakro 93, Namgu, Ulsan 680-749, Republic of Korea h i g h l i g h t s • PAC coating and mild heat treatment were combined for selective wetting of PVC. • The combined treatment rearranged the PVC surface and increased its hydrophobicity. • Optimized froth flotation was crucial for selective separation of the treated PVC. g r a p h i c a l a b s t r a c t a r t i c l e i n f o Article history: Received 3 June 2016 Received in revised form 25 August 2016 Accepted 5 September 2016 Available online 7 September 2016 Keywords: Mild heat treatment Surface modification Froth flotation PVC Recycling a b s t r a c t Polyvinyl chloride (PVC) containing chlorine can release highly toxic materials and persistent organic pol- lutants if improperly disposed of. The combined technique of powder activated carbon (PAC) coating and mild heat treatment has been found to selectively change the surface hydrophobicity of PVC, enhancing its wettability and thereby promoting its separation from heavy plastic mixtures included polycarbonate (PC), polymethyl methacrylate (PMMA), polystyrene (PS) and acrylonitrile butadiene styrene (ABS) by means of froth flotation. The combined treatments helped to rearrange the surface components and make PVC more hydrophobic, while the remaining plastics became more hydrophilic. After the treatments at 150 ◦ C for 80 s the contact angle of the PVC was greatly increased from 90.5 to 97.9 ◦ . The SEM and AFM reveal that the surface morphology and roughness changes on the PVC surface. XPS and FT-IR results further confirmed an increase of hydrophobic functional groups on the PVC surface. At the optimized froth flotation and subsequent mixing at 150 rpm, 100% of PVC was recovered from the remaining plastic mixture with 93.8% purity. The combined technique can provide a simple and effective method for the selective separation of PVC from heavy plastics mixtures to facilitate easy industrial recycling. © 2016 Elsevier B.V. All rights reserved. ∗ Corresponding author. E-mail addresses: bklee@ulsan.ac.kr, bklee.ulsan.kr@gmail.com (B.-K. Lee). http://dx.doi.org/10.1016/j.jhazmat.2016.09.014 0304-3894/© 2016 Elsevier B.V. All rights reserved.