Persistence of dissolved organic matter in sediments influenced by environmental factors：Implication for nutrition and carbon cycle.

The persistence of dissolved organic matter (DOM) plays a crucial role in the cycling and distribution of carbon and nutrients. Nonetheless, our understanding of how environmental alterations affect the persistence of sedimentary DOM remains incomplete. Excitation Emission Fluorescence Matrix-Parallel Factor Analysis (EEM-PARAFAC) was used to examine the fluorescence and compositional characteristics of hydrophilic and hydrophobic DOM (separated using XAD-8 resin) within sediments from twelve lakes and reservoirs. Fluorescence analysis indicated that DOM persistence is dependent on the proportions of the three components derived from PARAFAC. The Mantel test showed that climatic factors had the most significant impact on DOM persistence (Mantel's r = 0.46-0.54, Mantel's p = 0.001-0.007), while anthropogenic (Mantel's r = 0.24-0.32, Mantel's p = 0.03-0.05) and hydrological factors (Mantel's r = 0.03-0.22, Mantel's p = 0.06-0.40) had a somewhat lesser influence. Environmental changes resulted in a consistent decline in DOM persistence from Northeast to Southwest China, accompanied by an increase in gross primary productivity (GPP). Reduced DOM persistence due to climate, hydrological, and anthropogenic factors may lead to elevated concentrations of total phosphorus (TP), contributing to deteriorating water quality and events such as algal blooms. The decline in water quality due to reduced DOM persistence in lakes with high GPP can exacerbate the transition from carbon sinks to carbon sources. Consequently, the persistence of sedimentary DOM significantly influences nutrient and carbon cycling in lakes. Investigating DOM persistence in lakes across diverse geographic locations offers a new perspective on lake eutrophication and carbon emissions. Furthermore, it is crucial to develop targeted recommendations for lake restoration and management.

A Note on Stronger Forms of Sensitivity for Non-Autonomous Dynamical Systems on Uniform Spaces.

This paper introduces the notion of multi-sensitivity with respect to a vector within the context of non-autonomous dynamical systems on uniform spaces and provides insightful results regarding N-sensitivity and strongly multi-sensitivity, along with their behaviors under various conditions. The main results established are as follows: (1) For a k-periodic nonautonomous dynamical system on a Hausdorff uniform space (S,U), the system (S,fk∘⋯∘f1) exhibits N-sensitivity (or strongly multi-sensitivity) if and only if the system (S,f1,∞) displays N-sensitivity (or strongly multi-sensitivity). (2) Consider a finitely generated family of surjective maps on uniform space (S,U). If the system (S,f1,∞) is N-sensitive, then the system (S,fk,∞) is also N-sensitive. When the family f1,∞ is feebly open, the converse statement holds true as well. (3) Within a finitely generated family on uniform space (S,U), N-sensitivity (and strongly multi-sensitivity) persists under iteration. (4) We present a sufficient condition under which an nonautonomous dynamical system on infinite Hausdorff uniform space demonstrates N-sensitivity.

Simultaneous immobilization of ammonia and phosphorous by thermally treated sediment co-modified with hydrophilic organic matter and zeolite.

The use of calcined sediments (CS) for thin-layer capping is an environment-friendly technology for controlling nitrogen (N) or phosphorus (P) release. However, the effects of CS derived materials and efficiency in controlling the sedimentary N/P ratio have not been thoroughly investigated. While zeolite-based materials have been proven efficient to remove ammonia, it is limited by the low adsorption capacity of PO43-. Herein, CS co-modified with zeolite and hydrophilic organic matter (HIM) was synthesized to simultaneously immobilize ammonium-N (NH4+-N) and remove P, due to the superior ecological security of natural HIM. Studies on the influences of calcination temperature and composition ratio indicated that 600 °C and 40% zeolite were the optimal parameters leading to the highest adsorption capacity and lowest equilibrium concentration. Compared with doping with polyaluminum chloride, doping with HIM not only enhanced P removal but also achieved higher NH4+-N immobilization efficacy. The efficiency of zeolite/CS/HIM capping and amendment in prohibiting the discharge of N/P from sediments was assessed via simulation experiments, and the relevant control mechanism was studied at the molecular level. The results indicated that zeolite/CS/HIM can reduce 49.98% and 72.27% of the N flux and 32.10% and 76.47% of the P flux in slightly and highly polluted sediments, respectively. Capping and incubation with zeolite/CS/HIM simultaneously resulted in substantial reductions in NH4+-N and dissolved total P in overlying water and pore water. Chemical state analysis indicated that HIM enhanced the NH4+-N adsorption ability of CS owing to its abundant carbonyl groups and indirectly increased P adsorption by protonating mineral surface groups. This research provides a novel strategy to control sedimentary nutrient release by adopting an efficient and ecologically secure remediation method to rehabilitate eutrophic lake systems.

Effects of calcination on the environmental behavior of sediments by phosphorus speciation and interface characterization.

Dredged sediments derived from eutrophicated lakes poses hardness of sludge disposal and ecological risks. The proper pretreatment and utilization of dredged sediments presented a challenge. In this study, Dianchi Lake sediments were dredged, thermally treated and utilized as particle capping material in batch experiments. The effects of calcination on phosphorus speciation and sediment-water interface environment as well as P immobility mechanism were predominantly explored. The microstructures and chemical compositions of calcined sediments were investigated, indicating the porosity and mineralization components were greatly enhanced. The fractional analysis of phosphorus revealed that the calcination process reduced the percentage of unsteady phosphorus, transforming into stable inert phosphorus fractions (Al-P, Ca-P and Res-P), respectively, thereby minimized its mobility and eutrophication risk. Interestingly, calcination temperatures of 700 °C and 800 °C resulted in smaller releasing potentials and equilibrium phosphorus concentrations, despite having lower adsorption capacities than 550 °C. Furthermore, the results of redox potential monitoring showed that the thermally treated Dianchi Lake sediments could enhance the redox potential and dissolved oxygen in the surface sediment, indicating the amelioration of interfacial environment. The practical monitoring experiments confirmed the capping depressed the DTP to 0.031 mg L-1. The investigation of this study provided explicit evidence of Ca coupled P and aerobic Fe bound P strengthened the immobilization effects, and the development of sediment calcination demonstrates a promising strategy for alleviating the burden of endogenous pollution and improving aerobic environment, which are of great significance for lake ecological remediation.

Heterogeneity of molecular-level and photochemical of dissolved organic matter derived from decomposing submerged macrophyte and algae.

Aquatic macrophytes and algae are the most important sources of autochthonous dissolved organic matter (DOM), and their transformation and reuse significantly affect aquatic ecosystem health. In this study, Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) was used to identify the molecular features between submerged macrophyte-derived DOM (SMDOM) and algae-derived DOM (ADOM). The photochemical heterogeneity between SMDOM and ADOM by UV254-irradiation and their molecular mechanism were also discussed. The results showed that the molecular abundance of SMDOM was dominated by lignin/CRAM-like structures, tannins, and concentrated aromatic structures (sum of 91.79%), while that of ADOM was dominated by lipids, proteins, and unsaturated hydrocarbons (sum of 60.30%). UV254-radiation resulted in a net reduction of tyrosine-like, tryptophan-like and terrestrial humic-like, and conversely a net production of marine humic-like. The light decay rate constants obtained by the multiple exponential function model fitting revealed that both tyrosine-like and tryptophan-like components of SMDOM could be rapidly and directly photodegraded, while the photodegradation of tryptophan-like in ADOM depended on the production of photosensitizers. The photo-refractory fractions of both SMDOM and ADOM were as follows: humic-like > tyrosine-like > tryptophan-like. Our results provide new insights into the fate of autochthonous DOM in aquatic ecosystems where "grass-algae" coexist or evolve.

Fabrication and characterization of Ti/polyaniline-Co/PbO2-Co for efficient electrochemical degradation of cephalexin in secondary effluents.

The traditional interlayer of PbO2 electrode possessed many problems, such as short service lifetime and limited specific surface area. Herein, a novel and efficient Ti/polyaniline-Co/PbO2-Co electrode was conctructed employing cyclic voltammetry to introduce a Co-doped polyaniline interlayer and anodic electrodeposition to synthetize a ß-PbO2-Co active layer. Compared with pristine PbO2 electrode, Ti/polyaniline-Co/PbO2-Co exhibited more compact crystalline shape and higher active sites amounts. Pratically, the electrochemical degradation of 5 mg L-1 cephalexin in real secondary effluents was effectively achieved by the novel anode with 87.42% cephalexin removal and 71.8% COD mineralization after 120 min of 15 mA cm-2 electrolysis. The hydroxyl radical production and electrochemical stability were increased by 3.16 and 3.27 times respectively. The cephalexin degradation pathway was investigated by combining a density functional theory-based theoretical approach and LC-QTrap-MS/MS. The most likely cleavage point of the ß-lactam ring was the O=C-N bond, whose attack would produce small molecular compounds containing the thiazole and 4, 6-thiazine rings. Further oxidation produced inorganic ions; quantitative investigations indicated the amino groups to undergo decomposition to form aqueous NH4+, which was further oxidized to NO3-. The accumulation of NO3- and SO42-, combined with a decrease in toxicity toward Escherichia coli, demonstrated the efficient mineralization of cephalexin on the Ti/polyaniline-Co/PbO2-Co electrode.

Contamination profiles and risk assessment of per- and polyfluoroalkyl substances in groundwater in China.

Per- and polyfluoroalkyl substances (PFASs) have attracted attention due to the potential risk they pose to ecosystems and human health. A total of 169 groundwater samples were collected from four representative regions in order to analyze PFASs concentrations in China. The total concentration of PFASs (∑PFASs) in groundwater ranged from 0.05 to 198.80 ng L-1, with an average of 3.97 ng L-1. All targeted PFASs were detected in the studied areas. The detection frequency and average concentration of perfluorooctanoic acid (PFOA) were the highest (79.29% and 1.61 ng L-1, respectively). The contamination profiles of PFASs in each study area varied due to natural geographical conditions and human activities. According to the results of the potential source identification, the point sources of perfluorooctane sulfonate (PFOS) were mainly concentrated in Lanzhou, and the distribution of PFASs was slightly affected by atmospheric deposition in all the studied areas. The obtained concentrations of PFOA and PFOS may pose no threat to the residents due to water consumption.

Gene analysis of two cases with CisAB/B blood subgroup.

OBJECTIVE: To identify the precise ABO blood type subgroups with genotyping. METHOD: We screened ABO blood type from voluntary blood donors in our blood collection center. Samples were first examined with a routine serological method. Samples with ambiguous results were further examined with genotyping to identify ABO subgroups. RESULTS: Two samples identified as AweakB by serology were considered to be A/B and B/B by PCR-SSP. However, the gene sequencing results revealed the precise subgroup to be CisAB01/B101 and CisAB05/B101, respectively. CONCLUSION: It may be difficult to identify non-typical AB patients with a routine serological method. Genotyping is a more precise method to identify blood subgroups.

Gene identification of rare B(A) blood group.

OBJECTIVE: To study serologic and gene characteristics of the B(A) blood group of blood donation volunteers in Jilin Province, China. METHODS: ABO subgroups were identified by standard serologic techniques in ABO typing discrepancy samples from all donors at the Jilin Blood Center (410,354 non-repeat donors). DNA (deoxyribonucleic acid) was collected from each sample and PCR (polymerase chain reaction) was used to sequence exons 6 and 7 and intron 6, part 5 from the ABO subgroup samples. PCR products were sequenced to identify ABO subgroups and the B(A) allele. RESULTS: Four cases of B(A) blood type were found after sequencing, including two different alleles: B(A)02 and B(A)04. Three of the four alleles were B(A)04. CONCLUSION: Among blood donation volunteers in Jilin Province, China, B(A)04 is the most common B(A) blood group allele, followed by B(A)02. The B(A) blood group is associated with a complicated serologic phenotype and DNA detection is necessary for this atypical phenotype sample.

Multi-metals Measured at Sediment-Water Interface (SWI) by Diffusive Gradients in Thin Films (DGT) Technique for Geochemical Research.

Diffusive gradients in thin films (DGT) technique was used to determine pore water profile and to assess remobilization character of metals at sediment/water interface. The remobilization of Mn was due to redox reaction in profile, which engendered two large peaks: one with DGT concentration of 1355 µg L(-1) at depth of -4.75 cm in sediment and the other with DGT concentration of 1040 µg L(-1) at depth of -3.25 cm in sediment pore water. Fe reduction zone had a large peak of Fe (3209 µg L(-1)) at depth of -4.75 cm in sediment. Fe DGT-profile also indicated the little peaks and low values of dissolved Fe concentration in Fe-reduction/S-reduction boundary zone in sediment. Detailed correspondence of trace metals with Fe or Mn features in DGT-profiles suggested that their release is related to the reductive dissolution of Fe- or Mn-oxide.

Resolving the influence of nitrogen abundances on sediment organic matter in macrophyte-dominated lakes, using fluorescence spectroscopy.

A controlled experiment was designed to resolve the influence of nitrogen abundance on sediment organic matters in macrophyte-dominated lakes using fluorescence analysis. Macrophyte biomass showed coincident growth trends with time, but different variation rates with nitrogen treatment. All plant growth indexes with nitrogen addition (N, NH4Cl 100, 200, 400mg/kg, respectively) were lower than those of the control group. Four humic-like components, two autochthonous tryptophan-like components, and one autochthonous tyrosine-like component were identified using the parallel factor analysis model. The results suggested that the relative component changes of fluorescence in the colonized sediments were in direct relation to the change of root biomass with time. In the experiment, the root formation parameters of the plants studied were significantly affected by adding N in sediments, which may be related to the reason that the root growth was affected by N addition. Adding a low concentration of N to sediments can play a part in supplying nutrients to the plants. However, the intensive uptake of NH4(+) may result in an increase in the intracellular concentration of ammonia, which is highly toxic to the plant cells. Hence, our experiment results manifested that organic matter cycling in the macrophyte-dominated sediment was influenced by nitrogen enrichment through influencing vegetation and relevant microbial activity.

[Optical signatures of chromophoric dissolved organic matter in water body of Tien Lake].

The water samples of the Tien Lake were collected for the three-dimensional fluorescence spectrum detected. And parallel factor analysis (PARAFAC) and principal component analysis (PCA) were used for the spectra analyzing to know the main factor and relative contribution of the chromophoric dissolved organic matter (CDOM). PARAFAC decomposed CDOM into four components, the humic-like: C1 (240, 415), C3 (265, 525), C4 (255, 505) and the protein-like: C2(230/280, 330). The fluorescence intensity of CDOM components was high in north and estuary of the lake, but low in the other region. All the four components show significant positive correlations (p < 0.01), this result means they may have the same sources. Principal component analysis shows that these four components of the Tien Lake are all from terrestrial organic matter, meanwhile its DTN, DTP, DON may also come with the terrestrial substance. These components of Tien Lake can well be connected with dissolved nutrient salts by nonlinear multiple regression, which means we can use the three-dimensional fluorescence spectrum results of CDOM to indicate the eutrophication degree of Tien Lake.

The evolution of a typical plateau lake from macrophyte to algae leads to the imbalance of nutrient retention.

Long-term anthropogenic nitrogen (N) and phosphorus (P) inputs have led to lake eutrophication and decreased environmental quality. However, the imbalance in nutrient cycling caused by ecosystem transformation during lake eutrophication is still unclear. The N, P, organic matter (OM) and their extractable forms in the sediment core of Dianchi Lake were investigated. Combining ecological data and geochronological techniques, a coupling relationship between the evolution of lake ecosystems and nutrient retention was established. The results show that the evolution of lake ecosystems promotes the accumulation and mobilization of N and P in sediments, leading to an imbalance in nutrient cycling in the lake system. From the "macrophyte-dominated" period to the "algae-dominated" period, the accumulation rates of potential mobile N and P (PMN, PMP) in sediments have significantly increased, and the retention efficiency of total N and P (TN, TP) has decreased. The increased TN/TP ratio (5.38 ± 1.52 ‒ 10.19 ± 2.94) and PMN/PMP ratio (4.34 ± 0.41 ‒ 8.85 ± 4.16), as well as the reduced humic-like/protein-like ratio (H/P, 11.18 ± 4.43 ‒ 5.97 ± 3.67), indicated an imbalance in nutrient retention during sedimentary diagenesis. Our results show that eutrophication has resulted in the potential mobilization of N in sediments exceeding P, providing new insights for further understanding the nutrient cycle in the lake system and strengthening lake management.

Effect of dissolved organic matter and heavy metals ions on sorption of phenanthrene at sedimentary particle scale.

Human activities significantly increase the input of offshore heavy metals and organic pollutants. Although particle-scale and heterogeneous organic matters are fundamentally important to the fate of hydrophobic organic compounds (HOCs), deep understanding of the adsorption mechanism of HOCs on soil/sediment particles under the influence of heavy metal and organic pollution input is needed. This study investigates the effects of exotic DOM and heavy metals ions on the phenanthrene adsorption on sediment fractions. The adsorption experiments demonstrated that exotic DOM increased phenanthrene adsorption amount of sediment, with the greatest enhancement on clay particles (<2 µm). Nevertheless, the mechanism was differentiated accordingly to particle dimensions in terms of increased binding coefficients and mobility of phenanthrene. Furthermore, the introduction of heavy metals considerably enhanced the nonlinear sorption of phenanthrene. The Freundlich exponent N reduced by 0.01-0.24 when adding Cu2+, Zn2+ and Pb2+, especially for coarse particles (31-63 µm) fraction. In comparison, the enhancement of nonlinearity adsorption by Cu2+ and Zn2+ is significantly lower than Pb2+ ions. To our knowledge, the particle-scale study broadens the horizon of environmental fate and ecological risk of HOCs in intertidal regions, which is significantly affected by tidal action.

Particle-scale understanding sorption of phenanthrene on sediment fractions amended with black carbon and humic acid.

Black carbon (BC) and humic acid (HA) have been proposed to dominate the sorption behavior of phenanthrene in sediment. Nevertheless, little is known about the sorption mechanism that related to particle-scale by spiking of BC and HA in sediment particle size fractions. In this study, sorption isotherms for phenanthrene were determined in four particle-size sediment fractions (<2 µm, 2-31 µm, 31-63 µm and >63 µm) that amended with BC and HA, or not. The fitting results by Freundlich model indicated that the sediment particle size fractions amended with BC increased the sorption capacity and affinity for phenanthrene. Sediment coarser size fractions (31-63 µm and >63 µm) by spiking of BC contributed higher to sorption capacity factor (KF) and nonlinearity factor (n) than the finer size fractions (2-31 µm and <2 µm). By contrast, the sediment particle size fractions amended with HA enhanced the sorption distribution coefficient (Kd), but reduced the sorption affinity for phenanthrene. All these phenomena are obviously affected by the distribution of heterogeneous organic matter that related to sediment particle-scale. Results of this work could help us better understand the impact of increased BC and HA content in sediments on the sorption of hydrophobic organic pollutants (HOCs) and predict the fate of HOCs in offshore sediments due to tidal action.

Water depth determines spatial and temporal phosphorus retention by controlling ecosystem transition and P-binding metal elements.

Shallow lakes are more susceptible to eutrophication than deep lakes. The geochemical and biogeochemical mechanisms controlling the vulnerability to eutrophication for deep lakes and shallow lakes remain unknown. Therefore, we investigated the combined Phosphorus (P) retention mechanism with P fractions, water depth, distribution of P-binding metal elements, and macrophytes coverage in a degrading ecosystem of Erhai Lake. We concluded that different mechanisms control the P retention in deep-water areas and shallow-water areas. In shallow areas covered by macrophytes, the biogeochemical process manipulates the P retention by changing the total organic carbon (TOC), calcium (Ca) distributions and turbulence. In deep areas without macrophyte coverage, the aluminum (Al) and iron (Fe) distributions control the P retention by a physicochemical process. Manganese (Mn) was found to be a potential proxy in tracking the kinetic release and readsorb of redox-sensitive P (BD-P) in deep areas. The historical record and core sample indicate that the hydrological engineering induced water depth variation is a vital factor changing the ecosystem of Erhai Lake by forming a large area of intermediate area where macrophytes could only survive at low water level. The uplift of water level in the 1990s gradually changed the ecosystem of Erhai Lake from macrophyte-dominated to algal-macrophyte concomitant that reduced the accumulation of stable P fractions and their binding metals. Macrophytes were capable to preserve P in biomass in the macrophyte-dominated ecosystem, which released 150% and 72% of more labile organic P (NaOH25-nrP) and BD-P in the sediment after the deterioration than before, respectively. Therefore, water depth is a prerequisite to restoring the P preservation capacity of sediment and the macrophyte ecosystem. Further hydraulic engineering projects should consider the effect of water-level-variation-induced ecosystem transition.

[Fluorescence Spectral Characteristics of Dissolved Organic Matter in Songhua Lake Sediment].

Dissolved organic matter (DOM) has a significant impact on the main pollution indicators of the lake (e.g., COD), and sediment is the main source of pollution in the lake. Research on the fluorescence spectral characteristics of DOM in sediments is important to reveal the mechanism of lake pollution. In this study, sediments were collected from 20 sites in Songhua Lake. The DOM components in the sediment were analyzed using the excitation emission matrix-parallel factor analysis (EEM-PARAFAC) technique, and the properties of the sediment DOM were clarified via spectroscopy. Additionally, the relationship between DOM and eutrophication of the water column was explored. The results showed that four components were identified from the sediment DOM of Songhua Lake:humic-like C1 (330/415 nm), C2 (255/440 nm), C3 (365/470 nm), and protein-like C4 (280/355 nm). The high HIX and low BIX indicated that the source of sediment DOM was mainly terrestrial and included some biological sources. The spatial distribution of the fluorescence intensity of the four components was relatively similar, showing that the fluorescence intensity was higher in the upstream (S1-S7) than that in the downstream (S8-S20). The massive deposition of suspended particulate matter (SPM) carried by the three rivers (Huifa River, Songhua River, and Jiao River) was the main reason for this spatial distribution. Eutrophication status in the water column of Songhua Lake was similar to the fluorescence intensity distribution of sediment DOM. Meanwhile, there was a strong correlation between eutrophication level and sediment DOM fluorescence intensity in the downstream water column of Songhua Lake.

Importance of ammonia nitrogen potentially released from sediments to the development of eutrophication in a plateau lake.

Sedimentary nitrogen (N) in lakes significantly influenced by eutrophication plays a detrimental role on the ecological sustainability of aquatic ecosystems. Here, we conducted a thorough analysis of the importance of N potentially released from sediments during the shift of "grass-algae" ecosystem in plateau lakes. From 1964 to 2013, the average total amount of sedimentary potential mineralizable organic nitrogen (PMON) and exchangeable N in whole Lake Dianchi were 5.50 × 103 t and 3.44 × 103 t, respectively. NH4+-N was the main product (>90%) of sedimentary PMON mineralization. The PMON in sediments had great release potential, which tended to regulate the distribution of aquatic plants and phytoplankton in Lake Dianchi and facilitated the replacement of dominant populations. Moreover, NH4+-N produced by sedimentary PMON mineralization and exchangeable NH4+-N have increased the difficulty and complexity of ecological restoration in Lake Dianchi to a certain extent. This study highlights the importance of sedimentary N in lake ecosystem degradation, showing the urgent need to reduce the continuous eutrophication of lakes and restore the water ecology.

Biogeochemical dynamics of particulate organic phosphorus and its potential environmental implication in a typical "algae-type" eutrophic lake.

Organic phosphorus (Po) plays a very important role in the process of lake eutrophication, but there is still a lack of knowledge about the internal cycle of Po in suspended particulate matter (SPM) dominated by algal debris. In this study, the characterization of bioavailable Po by sequential extraction and enzymatic hydrolysis showed that 45% of extracted TP was Po in SPM of Lake Dianchi, and 43-98% of total Po in H2O, NaHCO3 and NaOH fractions was enzymatically hydrolyzable Po (EHP, H2O-EHP: 31-53%). Importantly, labile monoester P was the main organic form (68%) of EHP, and its potential bioavailability was higher than that of diester P and phytate-like P. According to the estimation of P pools in SPM of the whole lake, the total load of Pi plus EHP in the H2O extract of SPM was 74.9 t and had great potential risk to enhance eutrophication in the lake water environment. Accordingly, reducing the amount of SPM in the water during the algal blooming period is likely to be a necessary measure that can successfully interfere with or block the continuous stress of unhealthy levels of P on the aquatic ecosystem.

The adsorption-release behavior of sediment phosphorus in a typical "grass-algae" coexisting lake and its influence mechanism during the transition sensitive period.

In the early stage of eutrophication, the coexistence of "grass and algae" in lakes is obvious. Understanding the P sorption-desorption behavior in natural sediments during the ecologically sensitive transition period has important scientific value for predicting the deterioration of lake ecosystems and formulating restoration measures, but the related mechanisms are still unclear. In this study, the analysis results of sedimentary dissolved organic matter (DOM) fractions, extractable Fe (hydr)oxide fractions and P adsorption experiments showed that sedimentary DOM fractions, especially the tyrosine-like protein fractions and microbial humic-like fractions, played a part in determining the EPC0 and Kd values of sediments in the plateau lake environment. The compound effect of amorphous Fe (hydr)oxides and sedimentary OM affected the increase of sedimentary P adsorption. Interestingly, these phenomena were strongly correlated with water depth. Furthermore, the distribution of water depth to aquatic plants indirectly regulated the values of sedimentary EPC0 and Kd. Meanwhile, the ability of submerged plants to control the sedimentary EPC0andKd values will be forced to shift shallowly, thereby forcing a significant reduction of areas with low EPC0 and high Kd values. This not only enhanced the risk of endogenous P release in lakes, but also accelerated the further deterioration of aquatic ecosystems. Therefore, studying the long-term scale changes of sedimentary EPC0 and Kd values can help to understand the duration of the lake ecological transition period and prevent the transitional deterioration of ecosystem.