The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Srinivasa Reddy Mallampati - One of the best experts on this subject based on the ideXlab platform.
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sustainable recovery of precious metals from end of life vehicles shredder residue by a novel hybrid ball milling and nanoparticles enabled Froth Flotation process
Journal of Cleaner Production, 2018Co-Authors: Srinivasa Reddy Mallampati, Byoung Ho Lee, Yoshiharu Mitoma, Cristian SimionAbstract:Abstract It is hereby reported a simple, effective and sustainable method for the recovery of precious metals from end-of-life vehicle shredder residue and/or automobile shredder residue based on a hybrid ball-milling and microbubble Froth Flotation process. A ball-milling treatment of automobile shredder residue along a mixture of Fe/Ca/CaO nanoparticles had as main result the entrapment of precious metals and in subsidiary an improvement of the floatability of the various size fraction particles (1.0, 0.425, and 0.25 mm, respectively). Therefore, a separation of the settled fraction (poor in precious metals) and the floating fraction yielded a recovery of approximately 83–89% precious metals in the latter. Scanning electron microscopy-energy dispersive X-ray spectroscopy maps of gold (Au), silver (Ag), platinum (Pt), palladium (Pd), Iridium (Ir), and copper (Cu) confirmed that result.
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processing plastics from asr esr waste separation of poly vinyl chloride pvc by Froth Flotation after microwave assisted surface modification
Journal of Material Cycles and Waste Management, 2018Co-Authors: Srinivasa Reddy Mallampati, Chihyeon Lee, Min Hee Park, Byeongkyu LeeAbstract:The feasibility of the selective surface hydrophilization of poly vinyl chloride (PVC) using microwave treatment to facilitate the separation of PVC via Froth Flotation from automobile shredder residue (ASR) and electronic waste shredder residue (ESR) was evaluated. In the presence of powder-activated carbon (PAC), 60-s microwave treatment selectively enhanced the hydrophilicity of the PVC surface (i.e., the PVC contact angle decreased from 86.8° to 69.9°). The scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) results are consistent with increased hydrophilic functional groups (i.e., ether, hydroxyl, and carboxyl), amounting to significant changes in the morphology and roughness of the PVC surface after treatment. After only 60 s of microwave treatment, 20 % of the PVC was separated in virgin and ASR/ESR plastics with 33 and 29 % purity, respectively, as settled fractions by Froth Flotation at a 150 rpm mixing speed. The microwave treatment with the addition of PAC had a synergetic effect with the Froth Flotation, which brought about 100 and 90 % selective separation of PVC from the other virgin and ASR/ESR plastics, with 91 and 82 % purity. The use of the combined Froth Flotation and microwave treatments is an effective technology for separating PVC from hazardous waste plastics.
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development of hydrophobicity and selective separation of hazardous chlorinated plastics by mild heat treatment after pac coating and Froth Flotation
Journal of Hazardous Materials, 2017Co-Authors: Nguyen Thi Thanh Truc, Byeongkyu Lee, Chihyeon Lee, Srinivasa Reddy MallampatiAbstract:Abstract Polyvinyl chloride (PVC) containing chlorine can release highly toxic materials and persistent organic pollutants 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.
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hybrid selective surface hydrophilization and Froth Flotation separation of hazardous chlorinated plastics from e waste with novel nanoscale metallic calcium composite
Journal of Hazardous Materials, 2016Co-Authors: Srinivasa Reddy Mallampati, Je Haeng Heo, Min Hee ParkAbstract:Treatment by a nanometallic Ca/CaO composite has been found to selectively hydrophilize the surface of polyvinyl chloride (PVC), enhancing its wettability and thereby promoting its separation from E-waste plastics by means of Froth Flotation. The treatment considerably decreased the water contact angle of PVC, by about 18°. The SEM images of the PVC plastic after treatment displayed significant changes in their surface morphology compared to other plastics. The SEM-EDS results reveal that a markedly decrease of [Cl] concentration simultaneously with dramatic increase of [O] on the surface of the PCV samples. XPS results further confirmed an increase of hydrophilic functional groups on the PVC surface. Froth Flotation at 100rpm mixing speed was found to be optimal, separating 100% of the PVC into a settled fraction of 96.4% purity even when the plastics fed into the reactor were of nonuniform size and shape. The total recovery of PVC-free plastics in E-waste reached nearly 100% in the floated fraction, significantly improved from the 20.5wt% of light plastics that can be recovered by means of conventional wet gravity separation. The hybrid method of nanometallic Ca/CaO treatment and Froth Flotation is effective in the separation of hazardous chlorinated plastics from E-waste plastics.
Chong Qing Wang - One of the best experts on this subject based on the ideXlab platform.
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a novel process for separation of hazardous poly vinyl chloride from mixed plastic wastes by Froth Flotation
Waste Management, 2017Co-Authors: Jianchao Wang, Chong Qing Wang, Hui Wang, Lingling Zhang, Tao Wang, Long ZhengAbstract:A novel method, calcium hypochlorite (CHC) treatment, was proposed for separation of hazardous poly(vinyl chloride) (PVC) plastic from mixed plastic wastes (MPWs) by Froth Flotation. Flotation behavior of single plastic indicates that PVC can be separated from poly(ethylene terephthalate) (PET), poly(acrylonitrile-co-butadiene-co-styrene) (ABS), polystyrene (PS), polycarbonate (PC) and poly(methyl methacrylate) (PMMA) by Froth Flotation combined with CHC treatment. Mechanism of CHC treatment was examined by contact angle measurement, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Under the optimum conditions, separation of PVC from binary plastics with different particle sizes is achieved efficiently. The purity of PC, ABS, PMMA, PS and PET is greater than 96.8%, 98.5%, 98.8%, 97.4% and 96.3%, respectively. Separation of PVC from multi-plastics was further conducted by two-stage Flotation. PVC can be separated efficiently from MPWs with residue content of 0.37%. Additionally, reusing CHC solution is practical. This work indicates that separation of hazardous PVC from MPWs is effective by Froth Flotation.
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Separation of polyethylene terephthalate from municipal waste plastics by Froth Flotation for recycling industry
Waste Management, 2015Co-Authors: Chong Qing Wang, Hui Wang, You-nian LiuAbstract:Recycling is an effective way to manage plastic wastes and receives considerable attention. Since plastic mixtures are difficult to recycle because of their intrinsic characteristics, separation of mixed plastics is the key problem for recycling. Separation of polyethylene terephthalate (PET) from municipal waste plastics (MWP) by Froth Flotation combined with alkaline pretreatment was investigated for recycling industry. The effect of process variables was estimated by L9 (34) orthogonal array of experiments and single factor experiments. The optimum conditions of alkaline pretreatment are 10wt% sodium hydroxide, 20min and 70??C. After alkaline pretreatment under optimum conditions, Flotation separation PET from acrylonitrile-butadiene-styrene, polystyrene, polycarbonate or polyvinyl chloride was achieved with high purity and efficiency. The purity of PET is up to 98.46% and the recovery is above 92.47%. A flow sheet of separation PET from MWP by a combination of Froth Flotation and sink float separation was designed. This study facilitates industrial application of plastics Flotation and provides technical insights into recycling of waste plastics.
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Separation of polycarbonate and acrylonitrile-butadiene-styrene waste plastics by Froth Flotation combined with ammonia pretreatment
Waste Management, 2014Co-Authors: Chong Qing Wang, Jian-gang Fu, Hui Wang, Qun Liu, You-nian LiuAbstract:The objective of this research is Flotation separation of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping of Flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the Flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through Froth Flotation with ammonia pretreatment for different time (13. min at 23. ??C, 18. min at 18. ??C and 30. min at 23. ??C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability.
You-nian Liu - One of the best experts on this subject based on the ideXlab platform.
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Separation of polyethylene terephthalate from municipal waste plastics by Froth Flotation for recycling industry
Waste Management, 2015Co-Authors: Chong Qing Wang, Hui Wang, You-nian LiuAbstract:Recycling is an effective way to manage plastic wastes and receives considerable attention. Since plastic mixtures are difficult to recycle because of their intrinsic characteristics, separation of mixed plastics is the key problem for recycling. Separation of polyethylene terephthalate (PET) from municipal waste plastics (MWP) by Froth Flotation combined with alkaline pretreatment was investigated for recycling industry. The effect of process variables was estimated by L9 (34) orthogonal array of experiments and single factor experiments. The optimum conditions of alkaline pretreatment are 10wt% sodium hydroxide, 20min and 70??C. After alkaline pretreatment under optimum conditions, Flotation separation PET from acrylonitrile-butadiene-styrene, polystyrene, polycarbonate or polyvinyl chloride was achieved with high purity and efficiency. The purity of PET is up to 98.46% and the recovery is above 92.47%. A flow sheet of separation PET from MWP by a combination of Froth Flotation and sink float separation was designed. This study facilitates industrial application of plastics Flotation and provides technical insights into recycling of waste plastics.
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Separation of polycarbonate and acrylonitrile-butadiene-styrene waste plastics by Froth Flotation combined with ammonia pretreatment
Waste Management, 2014Co-Authors: Chong Qing Wang, Jian-gang Fu, Hui Wang, Qun Liu, You-nian LiuAbstract:The objective of this research is Flotation separation of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping of Flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the Flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through Froth Flotation with ammonia pretreatment for different time (13. min at 23. ??C, 18. min at 18. ??C and 30. min at 23. ??C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability.
Byeongkyu Lee - One of the best experts on this subject based on the ideXlab platform.
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processing plastics from asr esr waste separation of poly vinyl chloride pvc by Froth Flotation after microwave assisted surface modification
Journal of Material Cycles and Waste Management, 2018Co-Authors: Srinivasa Reddy Mallampati, Chihyeon Lee, Min Hee Park, Byeongkyu LeeAbstract:The feasibility of the selective surface hydrophilization of poly vinyl chloride (PVC) using microwave treatment to facilitate the separation of PVC via Froth Flotation from automobile shredder residue (ASR) and electronic waste shredder residue (ESR) was evaluated. In the presence of powder-activated carbon (PAC), 60-s microwave treatment selectively enhanced the hydrophilicity of the PVC surface (i.e., the PVC contact angle decreased from 86.8° to 69.9°). The scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) results are consistent with increased hydrophilic functional groups (i.e., ether, hydroxyl, and carboxyl), amounting to significant changes in the morphology and roughness of the PVC surface after treatment. After only 60 s of microwave treatment, 20 % of the PVC was separated in virgin and ASR/ESR plastics with 33 and 29 % purity, respectively, as settled fractions by Froth Flotation at a 150 rpm mixing speed. The microwave treatment with the addition of PAC had a synergetic effect with the Froth Flotation, which brought about 100 and 90 % selective separation of PVC from the other virgin and ASR/ESR plastics, with 91 and 82 % purity. The use of the combined Froth Flotation and microwave treatments is an effective technology for separating PVC from hazardous waste plastics.
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combining zno microwave treatment for changing wettability of weee styrene plastics abs and hips and their selective separation by Froth Flotation
Applied Surface Science, 2017Co-Authors: Nguyen Thi Thanh Truc, Byeongkyu LeeAbstract:Abstract This study reports a simple Froth Flotation method to separate plastic wastes of acrylonitrile–butadiene–styrene (ABS) and high impact polystyrene (HIPS) after initial hydrophilization by coating the plastics with ZnO and microwave treatment. ABS and HIPS are typical styrene-based WEEE plastics having similar density and hydrophobicity, which hinders their separation for recycling. After coating with ZnO, 2-min microwave treatment rearranged the ABS surface and thus changed its molecular mobility and increased its hydrophilicity. The combined ZnO coating/microwave treatment facilitated the selective separation of ABS and HIPS with 100% and 95.2% recovery and 95.4% and 100% purity in Froth Flotation, respectively. The combination of ZnO coating-microwave treatment and Froth Flotation can be utilized as a selective ABS/HIPS separation technique for improved recycling of WEEE plastics.
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development of hydrophobicity and selective separation of hazardous chlorinated plastics by mild heat treatment after pac coating and Froth Flotation
Journal of Hazardous Materials, 2017Co-Authors: Nguyen Thi Thanh Truc, Byeongkyu Lee, Chihyeon Lee, Srinivasa Reddy MallampatiAbstract:Abstract Polyvinyl chloride (PVC) containing chlorine can release highly toxic materials and persistent organic pollutants 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.
Hui Wang - One of the best experts on this subject based on the ideXlab platform.
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a novel process for separation of hazardous poly vinyl chloride from mixed plastic wastes by Froth Flotation
Waste Management, 2017Co-Authors: Jianchao Wang, Chong Qing Wang, Hui Wang, Lingling Zhang, Tao Wang, Long ZhengAbstract:A novel method, calcium hypochlorite (CHC) treatment, was proposed for separation of hazardous poly(vinyl chloride) (PVC) plastic from mixed plastic wastes (MPWs) by Froth Flotation. Flotation behavior of single plastic indicates that PVC can be separated from poly(ethylene terephthalate) (PET), poly(acrylonitrile-co-butadiene-co-styrene) (ABS), polystyrene (PS), polycarbonate (PC) and poly(methyl methacrylate) (PMMA) by Froth Flotation combined with CHC treatment. Mechanism of CHC treatment was examined by contact angle measurement, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Under the optimum conditions, separation of PVC from binary plastics with different particle sizes is achieved efficiently. The purity of PC, ABS, PMMA, PS and PET is greater than 96.8%, 98.5%, 98.8%, 97.4% and 96.3%, respectively. Separation of PVC from multi-plastics was further conducted by two-stage Flotation. PVC can be separated efficiently from MPWs with residue content of 0.37%. Additionally, reusing CHC solution is practical. This work indicates that separation of hazardous PVC from MPWs is effective by Froth Flotation.
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Separation of polyethylene terephthalate from municipal waste plastics by Froth Flotation for recycling industry
Waste Management, 2015Co-Authors: Chong Qing Wang, Hui Wang, You-nian LiuAbstract:Recycling is an effective way to manage plastic wastes and receives considerable attention. Since plastic mixtures are difficult to recycle because of their intrinsic characteristics, separation of mixed plastics is the key problem for recycling. Separation of polyethylene terephthalate (PET) from municipal waste plastics (MWP) by Froth Flotation combined with alkaline pretreatment was investigated for recycling industry. The effect of process variables was estimated by L9 (34) orthogonal array of experiments and single factor experiments. The optimum conditions of alkaline pretreatment are 10wt% sodium hydroxide, 20min and 70??C. After alkaline pretreatment under optimum conditions, Flotation separation PET from acrylonitrile-butadiene-styrene, polystyrene, polycarbonate or polyvinyl chloride was achieved with high purity and efficiency. The purity of PET is up to 98.46% and the recovery is above 92.47%. A flow sheet of separation PET from MWP by a combination of Froth Flotation and sink float separation was designed. This study facilitates industrial application of plastics Flotation and provides technical insights into recycling of waste plastics.
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Separation of polycarbonate and acrylonitrile-butadiene-styrene waste plastics by Froth Flotation combined with ammonia pretreatment
Waste Management, 2014Co-Authors: Chong Qing Wang, Jian-gang Fu, Hui Wang, Qun Liu, You-nian LiuAbstract:The objective of this research is Flotation separation of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping of Flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the Flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through Froth Flotation with ammonia pretreatment for different time (13. min at 23. ??C, 18. min at 18. ??C and 30. min at 23. ??C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability.
