Leaching of Flame Retardants from products deposited in Landfills
(English)Manuscript (Other academic)
Materials in many products in daily use are amended with chemicals to give them desired properties, e.g. flame retardants (FRs) used to reduce the risks of products catching fire. However, potential risks posed by some of these chemicals, including FRs, to the environment and human health have raised concerns. Hence, there is a need for more knowledge regarding the fate of FRs, notably in landfills, where many FR-containing products are deposited. This article presents analyses of FRs and derivatives in leachates sampled during laboratory-scale simulations of landfills containing various FR-containing products progressing through typical landfill ageing phases. The FRs represented substances used both reactively, i.e. bound to the flame-protected material and additively, i.e. without any covalent bonding to the product.The phosphorus-based Pyrovatex-FR and the brominated tetrabromobisphenol A (TBBPA) were used to represent the reactive FRs, and the nitrogen-based melamine and phosphorus-based FR of Proban the additive FRs. Residual FRs from the treatment of the materials were probably the main contributors to the leachates from all products. Their durability, i.e. ability to withstand laundry washes, was reflected in their leaching abilities, while the different landfill conditions were of minor importance, except for melamine (of which approximately 10% of the amount present in the test product leached and mineralised to carbon dioxide and ammonia, mainly during the period when the landfill models passed from acidogenic to methanogenic conditions). The other additively applied FR in Proban leached first during the later part of the incubation (between 80 and 112 weeks), in accordance with its laundry resistance. Substantial proportions of the residual chemicals in Pyrovatex-treated materials are generally lost during the first washing. Accordingly, early losses of the chemicals used in this treatment were detected during the landfill simulation. Elevated phosphate concentrations were also detected in simulations with the Pyrovatex- and Proban-treated products, suggesting that the FRs generated in these treatments were degraded during or after release to the leachate. Small amounts of TBBPA were observed at the end of the incubation, and no TBBPA degradation products were observed, but debromination (which is likely to occur during anoxic stages) would lead to the formation of bisphenol A.
IdentifiersURN: urn:nbn:se:liu:diva-15210OAI: oai:DiVA.org:liu-15210DiVA: diva2:113676