Plastic Paradox in Blue Carbon Ecosystems.

Plastics are rapidly accumulating in blue carbon ecosystems, i.e., mangrove forests, tidal marshes, and seagrass meadows. Accumulated plastic is diverted from the ocean, but the extent and nature of impacts on blue carbon ecosystem processes, including carbon sequestration, are poorly known. Here, we explore the potential positive and negative consequences of plastic accumulation in blue carbon ecosystems. We highlight the effects of plastic accumulation on organic carbon stocks and sediment biogeochemistry through microbial metabolism. The notion of beneficial plastic accumulation in blue carbon ecosystems is controversial, yet considering the alternative impacts of plastics on oceanic and aboveground environments, this may be the "lesser of evils". Using environmental life cycle impact assessment, we propose a research framework to address the potential positive and negative impacts of plastic accumulation in blue carbon ecosystems. Considering the multifaceted benefits, we prioritize expanding and managing blue carbon ecosystems, which may help with ecosystem conservation, as well as mitigating the negative effects of plastic.

Eukaryotes contribute more than bacteria to the recovery of freshwater ecosystem functions under different drought durations.

Global climate change mostly impacts river ecosystems by affecting microbial biodiversity and ecological functions. Considering the high functional redundancy of microorganisms, the unknown relationship between biodiversity and ecosystem functions obstructs river ecological research, especially under the influence of increasing weather extremes, such as in intermittent rivers and ephemeral streams (IRES). Herein, dry-wet alternation experiments were conducted in artificial stream channels for 25 and 90 days of drought, both followed by 20 days of rewetting. The dynamic recovery of microbial biodiversity and ecosystem functions (represented by ecosystem metabolism and denitrification rate) were determined to analyse biodiversity-ecosystem-function (BEF) relationships after different drought durations. There was a significant difference between bacterial and eukaryotic biodiversity recovery after drought. Eukaryotic biodiversity was more sensitive to drought duration than bacterial, and the eukaryotic network was more stable under dry-wet alternations. Based on the establishment of partial least squares path models, we found that eukaryotic biodiversity has a stronger effect on ecosystem functions than bacteria after long-term drought. Indeed, this work represents a significant step forward for further research on the ecosystem functions of IRES, especially emphasizing the importance of eukaryotic biodiversity in the BEF relationship.

Transformation of Biofilm to Carbon Sinks after Prolonged Droughts Linked with Algal Biodiversity Change.

Global climate change significantly increased the duration of droughts in intermittent rivers, impacting benthic microbial-mediated biogeochemical processes. However, the impact of prolonged droughts on the carbon contribution of intermittent rivers remains poorly understood. In this study, we investigated the potential effects of varying drought gradients (ranging from 20 to 130 days) on benthic biofilms community structure (algae, bacteria, and fungi) and their carbon metabolism functions (ecosystem metabolism and carbon dioxide (CO2) emission fluxes) using mesocosm experiments. Our findings indicate that longer drought durations lead to reduced alpha diversity and community heterogeneity, tighter interdomain networks, and an increased role of stochastic processes in community assembly, with a discernible threshold at around 60 days. Concurrently, the biofilm transforms into a carbon sink following a drought period of 60 days, as evidenced by the transformation of CO2 emission fluxes from 633.25 ± 194.69 to -349.61 ± 277.79 mg m-2 h-1. Additionally, the partial least-squares path model revealed that the resilience of algal communities and network stability may drive biofilm's transformation into a carbon sink, primarily through the heightened resilience of autotrophic metabolism. This study underscores the significance of the carbon contribution from intermittent rivers, as the shift in carbon metabolism functions with increasing droughts could lead to skewed estimations of current riverine carbon fluxes.

Effects of the Desiccation Duration on the Dynamic Responses of Biofilm Metabolic Activities to Rewetting.

Global climate changes have increased the duration and frequency of river flow interruption, affecting the physical and community structure of benthic biofilms. However, the dynamic responses of biofilm metabolism during the dry-wet transition remain poorly understood. Herein, the dynamic changes in biofilm metabolic activities were investigated through mesocosm experiments under short-term (25 day) and long-term drought (90 day), followed by a 20 day rewetting. The biofilm ecosystem metabolism, as measured by gross primary production and community respiration, was significantly inhibited and turned heterotrophic during the desiccation phase and then recovered, becoming autotrophic during the rewetting period regardless of the desiccation periods due to the high resilience of the autotrophic community. However, long-term drought decreased the recovery rate of the ecosystem metabolism and also caused irreparable damage to the biofilm carbon metabolism, measured using Biolog Eco Plates. Specifically, the recovery of the total carbon metabolic activity is related to the specific carbon source utilized by biofilm microorganisms, such as polymers, carbohydrates, and carboxylic acids. However, the divergent changes of amino acids caused the failure of the total carbon metabolism in long-term drought treatments to recover to the control level even after 20 days of rewetting. This research provides direct evidence that the increased duration of non-flow periods affects biofilm-mediated carbon biogeochemical processes.

Prioritising plastic pollution research in blue carbon ecosystems: A scientometric overview.

The Blue Carbon Ecosystems (BCEs), comprising mangroves, saltmarshes, and seagrasses, located at the land-ocean interface provide crucial ecosystem services. These ecosystems serve as a natural barrier against the transportation of plastic waste from land to the ocean, effectively intercepting and mitigating plastic pollution in the ocean. To gain insights into the current state of research, and uncover key research gaps related to plastic pollution in BCEs, this study conveyed a comprehensive overview using bibliometric, altmetric, and literature synthesis approaches. The bibliometric analysis revealed a significant increase in publications addressing plastic pollution in BCEs, particularly since 2018. Geographically, Chinese institutions have made substantial contributions to this research field compared to countries and regions with extensive BCEs and established blue carbon science programs. Furthermore, many studies have focused on mangrove ecosystems, while limited attention was given to exploring plastic pollution in saltmarsh, seagrass, and multiple ecosystems simultaneously. Through a systematic analysis, this study identified four major research themes in BCE-plastics research: a) plastic trapping by vegetated coastal ecosystems, b) microbial plastic degradation, c) ingestion of plastic by benthic organisms, and d) effects of plastic on blue carbon biogeochemistry. Upon synthesising the current knowledge in each theme, we employed a perspective lens to outline future research frameworks, specifically emphasising habitat characteristics and blue carbon biogeochemistry. Emphasising the importance of synergistic research between plastic pollution and blue carbon science, we underscore the opportunities to progress our understanding of plastic reservoirs across BCEs and their subsequent effects on blue carbon sequestration and mineralisation. Together, the outcomes of this review have overarching implications for managing plastic pollution and optimising climate mitigation outcomes through the blue carbon strategies.

Effects of microplastics on soil microorganisms and microbial functions in nutrients and carbon cycling - A review.

The harmful effects of microplastics (MPs) pollution in the soil ecosystem have drawn global attention in recent years. This paper critically reviews the effects of MPs on soil microbial diversity and functions in relation to nutrients and carbon cycling. Reports suggested that both plastisphere (MP-microbe consortium) and MP-contaminated soils had distinct and lower microbial diversity than that of non-contaminated soils. Alteration in soil physicochemical properties and microbial interactions within the plastisphere facilitated the enrichment of plastic-degrading microorganisms, including those involved in carbon (C) and nutrient cycling. MPs conferred a significant increase in the relative abundance of soil nitrogen (N)-fixing and phosphorus (P)-solubilizing bacteria, while decreased the abundance of soil nitrifiers and ammonia oxidisers. Depending on soil types, MPs increased bioavailable N and P contents and nitrous oxide emission in some instances. Furthermore, MPs regulated soil microbial functional activities owing to the combined toxicity of organic and inorganic contaminants derived from MPs and contaminants frequently encountered in the soil environment. However, a thorough understanding of the interactions among soil microorganisms, MPs and other contaminants still needs to develop. Since currently available reports are mostly based on short-term laboratory experiments, field investigations are needed to assess the long-term impact of MPs (at environmentally relevant concentration) on soil microorganisms and their functions under different soil types and agro-climatic conditions.

Dynamic responses of carbon metabolism of sediment microbial communities to Ag nanoparticles: Effects of the single and repeated exposure scenarios.

The widespread use of nanosilver will inevitably lead to their release into aquatic environment, threating the health of freshwater ecosystem. The toxic effects of silver nanoparticles (AgNPs) on sediment microbial diversity, community composition, and functional enzyme activity are well established, while little is known about how sediment microbes dynamically respond to the stress of different AgNPs exposure scenarios. Herein, microcosm experiments were performed to investigate the impacts of repeated (1 mg/L, applied every 6 days for 10 times) and single (10 mg/L) exposure scenarios of AgNPs on the specific functions of sediment microbes (5-60 days). The carbon metabolism of sediment microbial communities was measured using BIOLOG ECO microplates, and carbon metabolic rate and functional diversity indices were calculated. Compared to control group, the maximum carbon source utilization capacity of the microbial community increased by 6.6 and 15.4 % in the single and repeated exposure group, respectively. And the metabolic rates of sediment microorganisms were significant increased by 6.1 % in the repeated exposure group, which suggested that repetitive low-dosing of AgNPs induce a larger alteration of both capacity and rate of microbial carbon metabolism. Notably, different AgNPs exposure scenarios resulted in a shift in the carbon source preference of the microorganisms. After exposure for 60 days, compared with the controls, the ability to utilize polymers was significantly increased by 51.5 and 21.7 % in the single and repeated exposure groups, respectively, and decreased by 33.7 and 10.5 % in the utilization of miscellaneous, both exhibiting significant differences (P < 0.05), implying that AgNPs exposure scenarios affected the microbial-mediated carbon cycling processes in sediment. These results highlight that different exposure scenarios of AgNPs have different effects on the carbon metabolism capacity of microbial communities, thus affecting the carbon cycling processes in which microorganisms are involved.

Aquatic plastisphere: Interactions between plastics and biofilms.

Because of the high production rates, low recycling rates, and poor waste management of plastics, an increasing amount of plastic is entering the aquatic environment, where it can provide new ecological niches for microbial communities and form a so-called plastisphere. Recent studies have focused on the one-way impact of plastic substrata or biofilm communities. However, our understanding of the two-way interactions between plastics and biofilms is still limited. This review first summarizes the formation process and the co-occurrence network analysis of the aquatic plastisphere to comprehensively illustrate the succession pattern of biofilm communities and the potential consistency between keystone taxa and specific environmental behavior of the plastisphere. Furthermore, this review sheds light on mutual interactions between plastics and biofilms. Plastic properties, environmental conditions, and colonization time affect biofilm development. Meanwhile, the biofilm communities, in turn, influence the environmental behaviors of plastics, including transport, contaminant accumulation, and especially the fragmentation and degradation of plastics. Based on a systematic literature review and cross-referencing from these disciplines, the current research focus, and future challenges in exploring aquatic plastisphere development and biofilm-plastic interactions are proposed.

Characterization of dynamic plastisphere and their underlying effects on the aging of biodegradable and traditional plastics in freshwater ecosystems.

Recently, biodegradable plastics (BPs) are emerging as a sustainable alternative to traditional plastics. When released into an aquatic environment, the biodegradable performance of BPs is influenced by biochemical processes, especially the developed plastisphere. However, studies addressing the biodegrading capacity of BPs and traditional plastics within the plastisphere are still limited. Here, we investigated plastisphere community variations and their capacity to biodegrade polyethylene terephthalate (PET) and starch-based plastics (SBP) for four time periods (15, 30, 45, and 80 days) in three freshwaters. Unexpectedly, there is no significant difference in the microbial communities and network structure of the plastisphere between SBP and PET. Moreover, SBP tended to age rapidly at the early stage (0-15 days), while the aging degree of SBP and PET did not display an obvious difference at 80 days. Partial least squares path modeling suggested that plastic aging was mainly dominated by keystone taxa of network and aquatic environmental factors. These results suggest that the aging rate of commercial BPs may not be as fast as we imagine in freshwaters (SBP ≈ PET), and the environmental behaviors of BPs in the aquatic environment should be paid more attention to.

Sediment bacterial and fungal communities exhibit distinct responses to microplastic types and sizes in Taihu lake.

Microplastics (MPs) are emerging contaminants in aquatic environments, yet their impact on sediment microbiota and biogeochemical processes were not well reported. Herein, microcosm experiments were performed to investigate the effects of MPs (Polystyrene, PS and Polyethylene, PE) with three size classes (ranging from 100 nm to 150-200 µm) on sediment bacterial and fungal communities over 60-day incubation from Taihu Lake. High-throughput sequencing revealed the alpha diversities of bacterial and fungal communities were reduced by MPs, dependent on MPs' size and type. Bacterial community structures were significantly altered under all MPs treatments, with clustering for the same size class for PS and PE. Fungal community structures were significantly affected for all MPs, with PS and PE exhibiting different effects. Co-occurrence network analysis suggested MPs changed bacterial and fungal network complexities. Proteobacteria and Ascomycota formed strong associations with other phyla and demonstrated tolerance to MPs exposure. Actinobacteria, Firmicutes, and Chytridiomycota were the main respondents to MPs. The enzyme concentrations were stimulated by MPs, indicating carbon and nitrogen uptakes might be increased. Therefore, PS and PE had similar impacts on the microbial community (particularly bacteria), and sizes of MPs were the main influencing factors. MPs shifted community structure and network with distinct responses from bacteria and fungi, likely leading to the alteration of microbial-involved carbon and nitrogen cycling.

Surface modification significantly changed the effects of nano-polystyrene on sediment microbial communities and nitrogen metabolism.

Nanoplastics are ubiquitous in the natural environment, and their ecological risks have received considerable attention. Surface modification is common for nanoplastics and an essential factor affecting their toxicity. However, studies on the potential effects of nanoplastics and their surface-modified forms on functional communities in aquatic systems are still scarce. This study investigated the effects of nano-polystyrene (nPS), amino-modified nPS (nPS-NH2), and carboxylated nPS (nPS-COOH) particles on sediment bacterial and fungal communities and their functions over a 60-day incubation period. The results showed that the fungal community was significantly inhibited by nPS-NH2 exposure, while the bacterial community diversity remained relatively stable in all nPS treatments. Proteobacteria and Ascomycota were the dominant phyla for the bacterial and fungal communities, respectively. Nitrification was inhibited in all nPS treatments, while denitrification was enhanced for nPS-NH2 and nPS-COOH treatments. The activity of four key denitrification enzymes (NAR, NIR, NOR, and NOS) was also significantly improved by nPS, resulting in increased nitrogen and nitrous oxide gas production, and decreased nitrate concentrations in the overlying water. This showed the total increased effect of nPS on the activity of denitrifiers. Our results suggest that surface modification significantly affects the effects of nPS on microbial communities and functions. The potential impacts of nPS on ecological functions should be elucidated with more attention.

Spatio-temporal succession of microbial communities in plastisphere and their potentials for plastic degradation in freshwater ecosystems.

Plastics in the environment provide a new and unique habitat for microorganisms - known as the plastisphere. The microbial succession within the plastisphere and their potentials for plastic degradation in freshwater ecosystems is still not clear. Here, we investigated variation of microbial communities in plastisphere and their capacity to biodegrade non-biodegradable plastics (non-BPs), i.e., polypropylene (PP) and polyethylene (PE), and biodegradable plastics (BPs), i.e., polylactic acid+polybutylene adipate-co-terephthalate (PLA+PBAT) for four-time periods (15, 30, 45, and 80 days) in three freshwaters. Results showed that the aging degree of plastics increased with succession of plastisphere, with higher degradation rates of BP blends than those of non-BPs. High-throughput sequencing from 112 biofilm samples revealed that bacterial and fungal community structure of the plastisphere were potentially affected by plastic types and gradually converge during biofilm succession. The plastisphere of BPs reached the mature phase more quickly than those of non-BPs and increased co-exclusion to complete for resources. Furthermore, ecological networks involving plastic aging indices, environmental factors and bacterial and fungal operational taxonomic units were established. Ecological networks revealed that BPs may pose the ability to attract and retain key microorganisms (of the orders Bacillales, Myxococcales and Xanthomonadales) that significantly influence community composition such that biodegradative functions were increased in freshwaters.

Effects of released organic components of solid carbon sources on denitrification performance and the related mechanism.

Here, a hybrid scaffold of polyvinyl alcohol/sodium alginate (PVA/SA) was used to prepare solid carbon sources (SCSs) for treating low carbon/nitrogen wastewater. The four SCSs were divided into two groups, biodegradable polymers group (including polyvinyl alcohol-sodium alginate (PS) and PS-PHBV (PP), and blended SCSs (PS-PHBV-wood chips (PPW) and PS-PHBV-wheat straw (PPS)). After the leaching experiments, no changes occurred in elemental composition and functional groups of the SCSs, and the released dissolved organic matter showed a lower degree of humification and higher content of labile molecules in the blended SCSs groups using EEM and FT-ICR-MS. The denitrification performance of the blended SCSs was higher, with nitrate removal efficiency over 84%. High-throughput sequencing confirmed PPW had the highest alpha-diversity, and the microbial community structure significantly varied among SCSs. Results of functional enzymes and genes show the released carbon components directly affect the NADH level and electron transfer efficiency, ultimately influencing denitrification performance.

Can the carbon metabolic activity of biofilm be regulated by the hydrodynamic conditions in urban rivers?

Hydrodynamic regulation is widely used to improve the water quality of urban rivers. However, it is yet to explore substantially whether hydrodynamics could regulate the metabolic activity of biofilm in such aquatic systems. Herein, the pilot experiment of hydrodynamics in the rotation tanks was designed, including two experiment phases, namely constant flow and adjusting flow for 21 days and 14 days, respectively. In constant flow phase, biofilms grew in five shear stress gradients (R1-R5, 0.0044- 0.12 Pa). The carbon metabolic rate (k) of mature biofilms evaluated by BIOLOG ECO microplates showed a hump-shaped relationship with increasing shear stress, with R3 (0.049 Pa) the highest, while R5 (0.12 Pa) the lowest. To verify whether the metabolic activity of biofilm cultured at constant flow phase can be regulated by shear stress, we initiated the adjusting flow phase, and shear stress in reactors was reset uniformly at 0.049 Pa (with the highest k). Results showed the carbon metabolic activity of biofilm in reactor R4 and R5 increased rapidly by day 3, and there was no significant difference between the carbon metabolic rates among the five treatments by day 14. Meanwhile, the utilization levels of polymers and carbohydrates by biofilms were significantly different among the five treatments after hydrodynamic regulations. These results suggested that the total carbon metabolic activity of biofilm can be regulated by hydrodynamics, while the divergent changes of the specific carbon source category might affect the biofilm-mediated carbon biogeochemical processes, which should be considered for the application of hydrodynamic regulation in river ecological restoration projects.

Polystyrene nanoplastics change the functional traits of biofilm communities in freshwater environment revealed by GeoChip 5.0.

There is an increasing concern regarding the potential effects of nanoplastics (NPs) on freshwater ecosystems. Considering the functional values of biofilms in freshwater, knowledge on whether and to what extent NPs can influence the ecosystem processes of biofilms were still limited. Herein, the freshwater biofilms cultured in lab were exposed to 100 nm polystyrene NPs (PS-NPs) of different dosages (1 and 10 mg/L) for 14 days. Confocal laser scanning microscope observation indicated that biofilms were dominated by filamentous, and spiral algae species and the intensity of extracellular polymeric substances increased under PS-NPs exposure. GeoChip 5.0 analysis revealed that PS-NPs exposure triggered a significant increase in functional genes α diversity (p < 0.05) and altered biofilms' functional structure. Furthermore, the abundance of genes involved in the total carbon and nitrogen cycling were increased under PS-NPs exposure. The abundance of nitrogen fixation genes experienced the most pronounced increase (24.4%) under 1 mg/L PS-NPs treatment, consistent with the increase of ammonium in overlying water. Whereas antibiotic resistance genes and those related to photosynthetic pigments production were suppressed. These results provided direct evidence for PS-NPs' effects on the biofilm functions in terms of biogeochemical cycling, improving our understanding of the potentials of NPs on freshwater ecosystems.

Effects of Biofilms on Trace Metal Adsorption on Plastics in Freshwater Systems.

The formation of plastisphere on plastics and their potential impact on freshwater ecosystems have drawn increasing attention. However, there is still limited information about the effects of plastisphere on the heavy metal adsorption capacity and the related mechanism of plastic debris in different freshwaters. Herein, the trace metal adsorption capacity, kinetics and adsorption mechanisms of virgin and biofilm-covered plastic debris were investigated. Polypropylene (PP) and polyethylene terephthalate (PET) plastic debris were placed in three freshwaters (Xuanwu Lake, Donghu Lake and the Qinhuai River) for 45 days to incubate biofilms. Batch adsorption experiments were performed to compare the adsorption processes of trace metal on virgin and biofilm-covered plastics. Results showed that biofilms increase the adsorption of metals on plastics, and the adsorption isotherms were well fitted by the Langmuir model. Furthermore, the adsorption capacities for lead (Pb(II)) were higher than that of cadmium (Cd(II)) and zinc (Zn(II)), with 256.21 and 277.38 µg/g (Pb(II)) adsorbed in biofilm-covered PP and PET, respectively, in Xuanwu Lake. The adsorption kinetics of metals on plastic debris were significantly affected by the biofilms, by switching the intraparticle diffusion for virgin plastic debris to film diffusion for the biofilm-covered plastic debris. Moreover, the complexation of functional groups within the biofilms might mainly contribute to the increases of metal adsorption, involving the participation of oxygen and nitrogen groups. Overall, these results suggested that biofilms reinforce the potential role of plastics as a carrier of trace metals in freshwaters.

Waste plastic filter modified with polyaniline and polypyrrole nanoparticles for hexavalent chromium removal.

Chromium (Cr) is a toxic heavy metal for environmental compartments and human health. In this study, waste polypropylene hollow filters (PPF) with an optimal pore size of 5 µm were amino-functionalized with an optimized amount of polyaniline (PANI) and polypyrrole (PPy) as an adsorbent for removing Cr (VI). The adsorbent was characterized by scanning electron microscope, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, and the Brunauer-Emmett-Teller method, showing the successful polymerization of co-polymer on the surface of PPF and increasing the surface area up to 15.08 m2 g-1. A Box-Behnken design was applied by a quadratic model with 99.15% accuracy, revealing a significant impact of the initial concentration of Cr (VI) on the removal efficiency. Dynamic adsorption was conducted in a continuous and semi-continuous system with over 99% removal efficiency for various initial concentrations of Cr(VI). The fitted data showed that the adsorption process followed the pseudo-second-order kinetics and Langmuir isotherm models at the optimum pH of 2 with the predicted maximum adsorption capacity of 510.9 mg g-1 of PANI+PPy, which was significantly higher than some reported adsorbents. The effect of coexisting cations (Cu2+, Ni2+, and Zn2+) and anions (SO42-, Cl- and NO3-) on the removal efficiency revealed selective adsorption of Cr(VI) by the adsorbent. The produced adsorbent was capable of removing 76.6% of Cr(VI) from real electroplating wastewater. Regeneration of the adsorbent was performed by NaOH 1 mol L-1 up to three cycles with a 20% reduction in adsorption performance. All data showed that PPF@PANI+PPy was a promising adsorbent for Cr(VI) removal from aqueous solutions and real-world wastewater.

Effects of biofilm colonization on the sinking of microplastics in three freshwater environments.

Microplastics (MPs) have frequently been detected in freshwater environments, and there is growing concern about their ecological effects, especially the influence of the "plastisphere" on the freshwater ecosystems. The colonization of microbes on MPs would significantly alter their transport behavior, i.e., buoyancy, in fresh water. In this research, we studied the effects of biofilm colonization on the sinking and floating of three MPs, i.e., polyethylene terephthalate (PET), polypropylene (PP), and polyvinyl chloride (PVC), after 44 days of incubation in three freshwater systems (the Niushoushan River, the Qinhuai River, and East Lake) in China. The results showed that the biofilms attached to the three MPs contained different biomass and chlorophyll-a levels were related to water environmental conditions and physicochemical properties of MPs, based on redundancy analysis. Generally, PET and PVC sinking, with density higher than water, tended to increase after biofilm formation. Thereafter, the settling velocity of biofouled PET and PVC squares became faster than that of the virgin ones. In summary, our study suggested that biofouling does affect the sinking of MPs in fresh water and consequently influences the transport behavior and the distribution characteristics of MPs in freshwater environments, and this issue deserves more scientific attention.

Biofilm influenced metal accumulation onto plastic debris in different freshwaters.

Microbial biofilms can rapidly colonize plastic debris in aquatic environments and subsequently, accumulate chemical pollutants from the surrounding water. Here, we studied the microbial colonization of different plastics, including polyethylene terephthalate (PET), polypropylene (PP), polyvinyl chloride (PVC), and polyethylene (PE) exposed in three freshwater systems (the Qinhuai River, the Niushoushan River, and Donghu Lake) for 44 days. We also assessed the biofilm mass and associated metals attached to plastics. The plastics debris characteristics, such as contact angle and surface roughness, greatly affected the increased biofilm biomass. All types of metal accumulation onto the plastic substrate abundances significantly higher than the concentrations of heavy metal in the water column, such as Ba (267.75 µg/g vs. 42.12 µg/L, Donhu Lake), Zn (254 µg/g vs. 0.023 µg/L the Qinhuai River), and Cr (93.75 µg/g vs. 0.039 µg/L, the Niushoushan River). Compared with other metals, the heavy metal Ba, Cr and Zn accumulated easily on the plastic debris (PET, PP, PVC, and PE) at all incubation sites. Aquatic environmental factors (total nitrogen, total phosphorus, and suspended solids concentrations) largely shaped metal accumulation onto plastic debris compared with plastic debris properties.