Analysis of contaminants and their formation mechanism in the desiccation-dissociation process of organic impurity of waste glass

• Published in: Journal of hazardous materials 2021-08, Vol.416, p.125881-125881, Article 125881
• Main Authors: Qin, Baojia, Yao, Zichun, Deng, Kangzhi, Ruan, Jujun, Xu, Zhenming
• Format: Article
• Language: English
• Subjects: Desiccation-dissociation; Molecular dynamics; Organic impurity; Risk assessment; Waste glass
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.125881

The recovery of waste glass is an important issue in the fields of social sustainable development and resource recovery. The removal of organic impurity is the first step in the recovery of waste glass. Currently, desiccation-dissociation technology is advised to remove the organic impurity from waste glass. However, the risks of the organic impurity desiccation-dissociation process of waste glass have not been reported in the literature. In this paper, the environmental risks of the organic impurity desiccation-dissociation process of waste glass were assessed. The assessment results indicated that none of TSP (0.143 mg/m3), PM10 (0.090 mg/m3), heavy metals in air and residue after desiccation-dissociation were contaminated. However, the gas contained abundant organic contaminants, especially benzene, whose content was up to 5.26%. Molecular dynamics simulation and contaminant formation pathways analysis indicated that the formation of gaseous organic contaminants was because overmuch small molecular free radicals were generated at 200 °C and combined with each other. Hence, reducing the temperature of desiccation-dissociation, wearing gas masks, and placing organic gas contaminant absorption liquids are necessary protective measures. This paper provides scientific data for the green development of organic impurity desiccation-dissociation technology of waste glass. Meanwhile, this paper makes up for the shortage of the environmental information of the organic impurity desiccation-dissociation of waste glass. [Display omitted] •Exposure risk in the desiccation-dissociation process of waste glass was assessed.•Gas after desiccation-dissociation contained abundant organic contaminants.•TSP (0.143 mg/m3), PM10 (0.090 mg/m3) and heavy metals in air were safe.•Formation mechanism of gaseous contaminants was analyzed by molecular dynamics.