| Polybrominated diphenyl ether（PBDEs）,as the most commonly used brominated flame retardant,is widely used in plastics parts of electrical and electronic products.PBDEs pollution exists in various environmental media all over the world,and it has potential harm to human body and ecological environment.PBDEs has gradually become a hot spot that scholars at home and abroad pay more and more attention to.With the rapid development of science and technology and the rapid development of economy,electrical and electronic products have entered the peak of scrapping,and the production of electronic waste flame-retardant plastics is also showing a trend of rapid growth.The dual attributes of resource value and environmental pollution determine the importance of proper recycling of electronic waste plastics.Physical mechanical regeneration is commonly used in the market for the treatment of flame-retardant plastics,but there are few researches on the pollution and release of PBDEs around the process of mechanical regeneration at home and abroad.In view of this,based on the production and treatment of electronic waste flame-retardant plastics in China,the PBDEs pollution release and potential risk during mechanical regeneration were studied.The main research contents and results are as follows:Taking the electronic waste recovery and treatment enterprise of Shanxi Province as an example,the basic situation of recycling and dismantling of electronic waste is understood,and with the flow of flame-retardant plastics,the recycling and distribution sites of waste flame-retardant plastics are visited on the spot,and the conditions of recycling are obtained.That is melting-extrusion-cooling-granulation.The results showed that the detection rate of PBDEs in the sample was 100%.BDE-209isthemainpollutant,andthepollutionlevelofsoilis36ng/g-14727.1ng/g,which was similar to that in other regenerative enterprises.The results showed that PBDEs release and debromination occurred during the regeneration process.The concentration of PBDEs in cooling water was 1563.7ng/L,and the concentration of PBDEs in flue gas was5203945.8-7755113.2 ng/m3.The emission factors of cooling water and flue gas were 5484ng/kg and999157.6-1706124.9ng/kg.respectively.The human health risk assessment model was established to evaluate the human health risk caused by flue gas and recycled plastics reuse.The results showed that respiratory inhalation was the main way of flue gas exposure,the exposure amount was 11.6-17.5 mg/m3,and the carcinogenic risk value was higher than 10-4,which is not acceptable.The total exposures of regenerated PBDEs to adults and children were600.2pg/（kg×d）and 1433.1pg/（kg×d）,respectively.The corresponding hazard entropy values were 1.5×10-6-2.3×10-33 and 2.5×10-5-5.5×10-3,which were lower than 1.0,and the level of non-carcinogenic risk is acceptable. |
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