Aging behavior of microplastics affected DOM in riparian sediments: From the characteristics to bioavailability

Microplastics Reshape the Fate of Aqueous Carbon by Inducing Dynamic Changes in Biodiversity and Chemodiversity

“…8,20 As shown in Figure 1c−f, the higher fluorescence intensity in component 2 (humic-like) and the lower intensities in components 3 (tyrosine protein-like) and 4 (fulvic-like) in the MP treatments after the 48-day incubation supported the presence of less labile DOM (protein-like) and more refractory DOM (humic-like) in the water after MP exposure, which is consistent with a previous study showing that MPs promoted DOM humification in sediments. 17 To better understand the interactions between the DOM fractions and MPs, synchronous fluorescence analysis was conducted. The regions at 250−300, 300−355, 355−420 and 420−500 nm were assigned to the protein-like fluorescence (PLF) component, microbial humic-like fluorescence (MHLF) component, fulvic-like fluorescence (FLF) component and humic-like fluorescence (HLF) component, respectively.…”

“…DOM was classified into 5 regions (Figure a,b and Figure S5) and 4 components by PARAFAC analysis (Figure c–f, Figure S6 and Table S6). During the 48-day incubation, region (I + II) in all treatments accounted for a higher proportion than that in the initial water, indicating that labile DOM, including aromatic proteins such as tyrosine, was released into the water from the AOM. , As shown in Figure c–f, the higher fluorescence intensity in component 2 (humic-like) and the lower intensities in components 3 (tyrosine protein-like) and 4 (fulvic-like) in the MP treatments after the 48-day incubation supported the presence of less labile DOM (protein-like) and more refractory DOM (humic-like) in the water after MP exposure, which is consistent with a previous study showing that MPs promoted DOM humification in sediments …”

“…Higher DO was observed after 48 days of incubation with MPs (especially at 1 and 10 mg/L), indicating that MPs inhibited aerobic microbial respiration. SUVA254, E 253 / E 203 and S R reflect DOM aromaticity, substituent groups and molecular weight, respectively . The SUVA254 of DOM decreased on day 25 but increased on day 48 and was higher in the MP treatments at the end of the incubation (Table S5).…”

“…Waste from anthropogenic activities ( e.g ., daily use plastic items and industrial and agricultural wastewaters) accounted for approximately 360 million tons of MPs in 2019, but only 9% of the MPs were recycled and approximately 80% of the MPs in the ocean were discharged via river transport. , MPs are widespread in global aquatic systems, even in remote regions such as the Tibetan Plateau and the poles. , Most MPs discharged into rivers are stable, and the accumulation of MPs in river systems presents potential ecological risks, such as microbial community changes, even at a low concentration (1 μg/L) . MPs reduce DOM bioavailability (16–23%) and CO 2 emissions (19–26%) in sediments . In fact, MPs in water may have different fates than those in sediments because water-based microbes are distinct from sediment-based microbes .…”

Occurrence, distribution, and characteristics of microplastics in agricultural soil around a solid waste treatment center in southeast China

“…Corresponding studies have highlighted that the simultaneous exposure to MPs and heavy metals in soils joint affects soil properties, microbial diversity and functions (Feng et al 2022 ), root symbiosis, and plant performance (Wang et al 2020a ), and their combined toxicity is tremendously dangerous than individual toxicity (Khalid et al 2021 ; Yan et al 2020 ). Moreover, the weathering of MPs can significantly promote their heavy metal adsorption capacity (Chen et al 2022 ). A significant amount of plastic waste eventually ends up in landfills or incineration plants.…”