Occurrence and sorption behaviour of bisphenols and benzophenone UV-filters in e-waste plastic and vehicle fluff

Abstract

Bisphenols and benzophenone UV-filters are hazardous, high production volume chemicals. There is concern that these contaminants could leach into the environment or be recycled into new products during waste management. To investigate this, nine bisphenols and five benzophenones were quantified in Norwegian e-waste and car fluff. To understand their leachability, equilibrium passive sampling methodology, using polyoxymethylene (POM), was calibrated for these substances, many of which for the first time. This method can differentiate freely dissolved substances in the aqueous phase from those sorbed to suspended colloids and microplastics in the leachate water. Equilibrium POM partitioning was reached within 14 days of shaking; all bisphenols and benzophenone UV-filters exhibited linear isotherms (R2 ranged from 0.83 to 1.0), when deriving POM-water partition coefficients (KPOM). Bisphenol A and bisphenol F displayed the highest concentrations, with maximum levels of 246,000 and 42,400 ng g−1, respectively. Logarithms of waste-water partition coefficients (log Kwaste) ranged from 1.7 (benzophenone 2) to 4.5 (bisphenol P). The established KPOM values agreed with measured Kwaste values (within a factor of ~3), unlike octanol-water partition coefficients. This indicated that POM is a better surrogate for waste plastic partitioning than octanol. Results are discussed in the context of assessing risks from waste management in a circular economy.