Formation of disinfection by-products due to the leaching of dissolved organic matter from artificial grass and tyre

ABSTRACT This study examined the leaching behaviour of dissolved organic matter (DOM) and disinfection by-products (DBPs) formation from artificial grass and tyre in rainwater and deionized water (DI water). The results demonstrated that tyre (DOC leaching: 2.138–3.349 mg/L in DI water and 0.791–1.654 mg/L in rainwater) released greater quantities of DOM than artificial grass (DOC leaching: 0.663–1.477 mg/L in DI water and not detected – 0.694 in rainwater), attributable to their higher additive contents. Environmental factors significantly influenced leaching dynamics, with ultraviolet (UV) radiation inducing more substantial DOM release compared to natural light/dark conditions due to its ability to alter surface characteristics of plastic materials. Following chlorination, DOM leached from the tyre generated more trihalomethanes (THMs) (ΣTHMs after 72 h chlorination: 41.13–76.32 μg/L in rainwater and 94.75–178.56 μg/L in DI water) than that from artificial grass (ΣTHMs after 72 h chlorination: not detected-16.23 μg/L in rainwater and 31.49–51.10 μg/L in DI water). Notably, UV radiation enhanced the THM formation potential of DOM from both plastic products. Outcomes raise concerns that DOM leaching from commercial plastics in rainwater and its subsequent DBP formation pose potential health risks, impacting its reuse safety. This research can contribute to a better understanding of reuse safety implications for plastic-containing rainwater.