title: Thermochemical reaction mechanism of lead oxide with poly(vinyl chloride) in waste thermal treatment.
abstract: Poly(vinyl chloride) (PVC) as a widely used plastic that can promote the volatilization of heavy metals during the thermal treatment of solid waste, thus leading to environmental problems of heavy metal contamination. In this study, thermogravimetric analysis (TGA) coupled with differential scanning calorimeter, TGA coupled with Fourier transform infrared spectroscopy and lab-scale tube furnace experiments were carried out with standard PVC and PbO to explicate the thermochemical reaction mechanism of PVC with semi-volatile lead. The results showed that PVC lost weight from 225 to 230°C under both air and nitrogen with an endothermic peak, and HCl and benzene release were also detected. When PbO was present, HCl that decomposed from PVC instantly reacted with PbO via an exothermal gas-solid reaction. The product was solid-state PbCl2 at <501°C, which was the most volatile lead-containing compound with a low melting point and high vapor pressure. At >501°C, PbCl2 melted, volatilized and transferred into flue gas or condensed into fly ash. Almost all PbCl2 volatilized above 900°C, while PbO just started to volatilize slowly at this temperature. Therefore, the chlorination effect of PVC on lead was apt to lower-temperature and rapid. Without oxygen, Pb2O was generated due to the deoxidizing by carbon, with oxygen, the amount of residual Pb in the bottom ash was significantly decreased.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, 1239 Siping Road, Shanghai 200092, PR China; Institute of Waste Treatment and Reclamation, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
authors.forename: Si-Jia
authors.initials: SJ
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, 1239 Siping Road, Shanghai 200092, PR China. Electronic address: zhanghua_tj@tongji.edu.cn.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Institute of Waste Treatment and Reclamation, Tongji University, 1239 Siping Road, Shanghai 200092, PR China; Centre for the Technology Research and Training on Household Waste in Small Towns & Rural Area, Ministry of Housing and Urban-Rural Development of PR China, 1239 Siping Road, Shanghai 200092, PR China.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Shao
authors.affiliation: Institute of Waste Treatment and Reclamation, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
authors.forename: Shu-Meng
authors.initials: SM
authors.lastname: Liu
authors.affiliation: Institute of Waste Treatment and Reclamation, Tongji University, 1239 Siping Road, Shanghai 200092, PR China; Centre for the Technology Research and Training on Household Waste in Small Towns & Rural Area, Ministry of Housing and Urban-Rural Development of PR China, 1239 Siping Road, Shanghai 200092, PR China. Electronic address: solidwaste@tongji.edu.cn.
authors.forename: Pin-Jing
authors.initials: PJ
authors.lastname: He
mesh_terms: D002152:Calorimetry, Differential Scanning; D004785:Environmental Pollutants / Q000737:chemistry*; D017745:Incineration; D007854:Lead / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D011143:Polyvinyl Chloride / Q000737:chemistry*; D012037:Refuse Disposal; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry
chemical_list: D004785:Environmental Pollutants; D010087:Oxides; D007854:Lead; C029891:lead chloride; C047365:lead oxide; D011143:Polyvinyl Chloride
keywords: Lead; Poly(vinyl chloride); Reaction mechanism; Thermal treatment; Volatilization