title: Selective sequential separation of ABS/HIPS and PVC from automobile and electronic waste shredder residue by hybrid nano-Fe/Ca/CaO assisted ozonisation process.
abstract: The separation of plastics containing brominated flame retardants (BFR) like (acrylonitrile-butadiene-styrene (ABS), high-impact polystyrene (HIPS), and polyvinyl chloride (PVC)) from automobile and electronic waste shredder residue (ASR/ESR) are a major concern for thermal recycling. In laboratory scale tests using a hybrid nano-Fe/Ca/CaO assisted ozonation treatment has been found to selectively hydrophilize the surface of ABS/HIPS and PVC plastics, enhancing ABS wettability and thereby promoting its separation from ASR/ESR by means of froth flotation. The water contact angles, of ABS/HIPS and PVC decreased, about 18.7°, 18.3°, and 17.9° in ASR and about 21.2°, 20.7°, and 20.0° in ESR respectively. SEM-EDS, FT-IR, and XPS analyses demonstrated a marked decrease in [Cl] and a significant increase in the number of hydrophilic groups, such as CO, CO, and (CO)O, on the PVC or ABS surface. Under froth flotation conditions at 50rpm, about 99.1% of combined fraction of ABS/HIPS in ASR samples and 99.6% of ABS/HIPS in ESR samples were separated as settled fraction. After separation, the purity of the recovered combined ABS/HIPS fraction was 96.5% and 97.6% in ASR and ESR samples respectively. Furthermore, at 150rpm a 100% PVC separation in the settled fraction, with 98% and 99% purity in ASR and ESR plastics, respectively. Total recovery of non-ABS/HIPS and PVC plastics reached nearly 100% in the floating fraction. Further, this process improved the quality of recycled ASR/ESR plastics by removing surface contaminants or impurities.
authors.affiliation: Department of Civil and Environmental Engineering, University of Ulsan, Daehak-ro 93, Nam-gu, Ulsan 680-749, Republic of Korea. Electronic address: srireddys@ulsan.ac.kr.
authors.forename: Srinivasa Reddy
authors.initials: SR
authors.lastname: Mallampati
authors.affiliation: Department of Civil and Environmental Engineering, University of Ulsan, Daehak-ro 93, Nam-gu, Ulsan 680-749, Republic of Korea.
authors.forename: Byoung Ho
authors.initials: BH
authors.lastname: Lee
authors.affiliation: Department of Environmental Sciences, Prefectural University of Hiroshima, 562 Nanatsuka-Cho, Shobara City, Hiroshima 727-0023, Japan.
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Mitoma
authors.affiliation: Politehnica University of Bucharest, Department of Organic Chemistry, Bucharest 060042, Romania. Electronic address: c_simion@chim.upb.ro.
authors.forename: Cristian
authors.initials: C
authors.lastname: Simion
mesh_terms: D000181:Acrylonitrile; D001336:Automobiles; D002070:Butadienes; D002118:Calcium / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry; D059029:Electronic Waste; D057927:Hydrophobic and Hydrophilic Interactions; D007501:Iron / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D010087:Oxides / Q000737:chemistry; D010126:Ozone / Q000737:chemistry*; D011137:Polystyrenes; D011143:Polyvinyl Chloride; D059027:Recycling / Q000379:methods*; D012037:Refuse Disposal / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared; D014866:Waste Products / Q000032:analysis
chemical_list: D002070:Butadienes; D017610:Calcium Compounds; D010087:Oxides; D011137:Polystyrenes; D014866:Waste Products; D010126:Ozone; D011143:Polyvinyl Chloride; C016538:lime; D007501:Iron; C031763:1,3-butadiene; D000181:Acrylonitrile; D002118:Calcium
keywords: ABS/PVC; Automobile shredder residue; E-waste; Hydrophilization; Ozonisation