Abstract
Riparian zone is a hub for microplastics (MPs), and MPs accumulation also changes the function of the riparian zone (e.g., carbon pool) to pose a great threat to river ecosystems. Although it is known that MPs can be aged for changing their characteristic after accumulating in riparian sediment, the effect of MP aging behavior on sediment dissolved organic matter (DOM) bioavailability and carbon emission has not been elucidated. In this study, effects of pristine and aged MPs on the DOM characteristics and components were investigated in sediment. The results showed that pristine MPs increased DOM humification and promoted the formation of larger molecular weight components, thereby reducing DOM bioavailability by approximately 16~23% and inducing negative priming effect. However, inhibition of MPs on DOM bioavailability and the priming effect decreased with aging behavior. Mathematical models revealed that the fulvic acid-like substance of sediment DOM was the driven factor in the influence of sediment carbon stability. Further microbial analysis found that higher carbohydrate metabolism promoted DOM humification, thereby reducing CO2 emissions approximately by 19~26% after MPs accumulation. Thus, this study provided an integrated picture to understand the risk of MPs accumulation in sediment for a long term on terrestrial and aquatic ecosystems.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
