Brominated flame retardants (BFRs) including PBDEs(polybrominated dephenyl ethers), TBBPA (tetrabromobisphenol A), and HBCD (hexabromocyclododecane) have been used in a variety of products such as electrical and electronic equipment (EEE), automotives parts, construction and demolition materials, and textiles.
Because some of BFRs are known to be toxic, persistent, bioaccumulative in the environment, they have a great potential for human exposure and the environmental release through the use, treatment and disposal of products and waste materials containing BFRs.
In this study, we investigated such products and wastes for the BFRs levels, material flow analysis (MFA) based on the concentrations and available statistics. We also analyzed the behavior of emission to the environment and stock of PBDEs (polybrominated diphenyl ethers) in TVs by 2030 by using dynamic flow analysis. Finally, we suggested the proper management of the waste containing BFRs in Korea.
Samples of selected products and wastes were collected, 135 for EEE, 36 for automotive pats, 77 for building materials and 14 for textiles. The total number of sampling samples was 262. BFRs content analysis was performed on the collected samples after XRF screening and the analysis results were compared with the results of previous studies. A total of 211 samples were analyzed: 95 for EEE, 36 for automotive parts, 77 for construction materials and 14 for textiles.
The results showed that the concentrations of PBDEs detected from the CRT TV samples ranged from 133 mg/kg to 18,467 mg/kg with an average of 7,739 mg/kg, while the concentrations of PBDEs detected from the automobile samples ranged from 2,587 mg/kg to 37,498 mg/kg with an average of 14,752 mg/kg. The construction and demolition waste samples contained significant levels of HBCD, ranging from 1,848 mg/kg to 20,085 mg/kg. In the case of CRT TV and automobiles, the concentrations of BFRs were lower than those of the previous studies.
The results of the domestic static material flow analysis of the TV and PBDEs showed that domestic TV production was estimated about 200,900 ton, and used and kept TV at households were estimated about 770,000 ton in 2017. In the case of waste TVs, only 42,000 ton was collected at recycling facilities. And about 68,000 ton was discharged into informal system. In the case of PBDEs, the total shipment and the use at household were about 94 tons and 36 tons respectively, and the amount collected in the recycling facillities was about 57 ton. The amount recycled as a plastic injection molding company was about 65 ton.
According to the results of the static flow analysis of HBCD, the amount used as raw material was 2,561 ton, mainly imported in 2016. The amount of HBCD used to the final product was 1,673 ton, and the amount used and stocked were 9,063 ton. Only 67 ton was collected. Recycling amounts were 35 ton, while the amount of incineration and landfilling was 32 ton. Most recycled amount was used for recycled pellets in plastics.
As a result of the dynamic material flow analysis, the cumulative emission of PBDEs at the manufacturing stage was 18,426 ton. In the use stage, no CRT TVs are expected to be generated after 2016. The estimated PBDEs emission from LCD TVs in 2030 was about 39 ton. In the collection and recycling stage, the overall PBDEs emissions were the lowest in 2017. The estimated 2030 emissions from the collection and recycling stages were about 48 ton and 16 ton, respectively.
As a result of the determination of the PBDEs emissions by 2030 using scenario 1 for CRT TVs, emission amounts of PBDEs have been linearly reduced from 2001 to 2018. After 2019, PBDEs have been rarely released. For LCD TVs, PBDEs emission at 2030 was 36 ton. In scenario 2 for CRT TVs, emission behavior of PBDEs was similar to scenario 1. For LCD TVs, PBDEs emission at 2030 was 37 ton. Comparing with the results of the analysis of static material flows in 2017, the second scenario was similar to the emissions estimates and those obtained by static material flow analysis.
As a result of estimating the amount of environmental emissions by domestic life cycle, it was found that in the case of TV, 40 kg of PBDEs were discharged into the water, while the PBDEs emissions to the atmosphere and soil were 5 kg and 9 kg, respectively.
Finally, we proposed guidelines and system for the proper management and treatment for waste containing BFRs according to the levels of BFRs. By setting standards for the BFRs content of the wastes based on the PBDEs content (1,000 mg/kg) and HBCD content (100 mg/kg), it must be prohibited for landfilling if it exceeds the standards and properly incinerated at the higher temperature than 1,100 ℃.