Brominated organic compounds in leachate across China: Occurrence and molecular variations

At present, China is the world’s largest producer and consumer of brominated flame retardants (BFRs). Substantial quantities of BFRs are washed out of waste from landfill and incineration sites, and are become part of the contaminated leachate. However, the occurrence and molecular variations of brominated organic compounds (BOCs) in leachate across China remains largely unexplored. Upon collecting leachate samples from 87 landfill or incineration sites throughout China, the BOCs are explored using Fourier transform ion cyclotron resonance mass spectrometry coupled with the neutral model. The results show that ∼80.5% of the leachate samples contain no more than 30 brominated organic molecules (BOMs), and 347 BOMs are detected across China, with monobrominated organic molecules constituting 86.5%. These identified BOMs include aliphatics (123 types), polyphenols (67 types), condensed aromatics (68 types), amino sugar (42 types), and carbohydrates (19 types). They possess 5–12 carbon atoms and are highly unsaturated, strongly aromaticit, and less biodegradable. Evidently, the molecular variations of BOCs are more stochastic in landfill leachate compared with those in incineration leachate. This study presents a nontargeted survey of BOCs in leachate at a national scale in China, providing a scientific basis for risk assessment and pollution control of BOCs in leachate.