The study summarized the characteristics of periphyton biology, investigating of periphyton bioregulation technology in water and soil ecological restoration and greenhouse gas regulation. The application scenarios of periphyton biocapture and bioregulation technology that utilizes the enrichment and removal characteristics of pollutants by periphyton and their mediating carbon cycle functions were expounded. The effect and function of applying this technology in enriching and removing novel environmental pollutants and resource recovery under environmental stress were discussed in depth. Its potential advantages for ecological community restoration and ecosystem regulation were clarified. Finally, constructing a systematic and integrated periphyton bioregulation technology based on spatial optimization of water-soil interface, coupling with the integration of new technologies for the enhancement of periphyton functions, was proposed, which will provide a perspective for the application of periphyton bioregulation technology in the ecological restoration of the water-soil interface. The prospects provide technical support for green and low-carbon secondary resource recycling technology.

Connectivity restoration and ecological water replenishment aim to enhance hydrological connectivity, thereby strengthening water exchange and purifying water quality through increased water mobility and water reoxygenation capacity. This study introduces the impact of connectivity restoration and ecological water replenishment on the ecosystem of various river-lake water systems, examining four aspects, including water quality, water dynamics, plant life, and animal population. The study identifies several challenges that require resolution in the connectivity of river-lake systems and proposes recommendations for future research to address these issues effectively.

Considering the advantage of the Canadian council of ministers of the environment water quality index (CCME-WQI), this study evaluated the rivers and lakes water quality in the Taihu Lake Basin from 2013 to 2017. This study aimed to devise an efficient approach for water quality assessment, providing a scientific and straightforward management tool for watershed agencies in China. Results showed that BOD₅, COD_Cr, COD_Mn, and phosphorus were widespread and persistent pollution sources within the Taihu Lake Basin during the study period. Additionally, ammonia-nitrogen nutrients emerged as a potentially contributorto pollution, while heavy metals were identified as episodic pollutants. Based on the CCME-WQI scoring system, indicated “moderate” water quality for the basin. Spatial heterogeneity was observed in water quality, with “good” water quality around the South River systems and the Camps Creek. Temporal variation of water qualitywas also observed, the CCME-WQI values increases continuously over the study period. Seasonally, the highest CCME-WQI values was observed in autumn, followed by summer and winter, with the spring lowest. This study accurately evaluated the water quality of the Taihu Lake Basin using CCME-WQI method, providing a suitable and reliable tool for water quality evaluation in China.

In this study, in-situ simulated control experiments were conducted to investigate the effects of straw burial on vegetation recovery and carbon sequestration function of eutrophic salt marshes, by monitoring plant growth traits, photosynthetic characteristics, and greenhouse gas fluxes, as well as the soil organic carbon density measured at the end of the experiment. The results revealed that under a high exogenous nitrogen input, straw burial was beneficial for the growth of Phragmites australis and carbon sequestration of wetland, specifically by promoting CO₂ uptake, inhibiting CH₄ emissions, and increasing soil organic carbon density. The findings of this study aim to address the current lack of understanding regarding the carbon sequestration potential of salt marsh ecosystems. Through investigating the utilization of salt marsh straw, this study can provide technical support for vegetation restoration and carbon sequestration in the coastal wetlands, and may help promote the utilization of salt marsh straw.

The SLAMM (Sea Level Affecting Marshes Model) is employed to simulate a wetland’s evolution by considering scenarios of sea level rise and whether the wetland is protected by seawalls. This study investigates the effects of tidal range, slope, and land subsidence on wetland stability. The findings are as follows: ① Chongming Dongtan wetland will be reduced in size in future under the influence of sea level rise. From 2020 to 2050, its wetland area retention rate will be 0.732 ~ 0.763. In addition, the Chongming Dongtan wetland is expected to begin shrinking as early as 2039. ② The seawall in the restored area of Chongming Dongtan wetland can prevent reverse succession and transitional salt marsh during the response to sea level rise; ③ The changes in tidal range, slope, and land subsidence can affect the stability of the Chongming Dongtan wetland. If the goal is to stabilize Chongming Dongtan wetland by 2050, the tidal range must reach at least 3.0 meters or the slope of the profile must be above 2.06‰.

Estuarine wetlands are important components of coastal ecosystems that contribute tremendously to global blue carbon sinks. The amount and quality of dissolved organic matter (DOM) vary significantly with tidal exchange and seasonal cycles. Focusing on the Chongming Dongtan salt marshes in Shanghai under the influence of the Yangtze River, we conducted high-frequency sampling across a complete tidal cycle in each season and characterized the dynamics of the quantity (expressed by the C content in DOM, i.e., the concentration of dissolved organic carbon (DOC)) and spectral characteristics (expressed by the light absorption characteristics of chromophoric DOM (CDOM)) of DOM across tidal and seasonal scales. The results indicated that on the tidal scale, waters leaving the marshes during the ebbing tide were rich in DOC, strong in optical absorbance (${a_{{\rm{CDOM}}}} $(350) and ${a_{{\rm{CDOM}}}^*} $(350)), with high aromaticity (specific ultraviolet absorbance, SUVA₂₅₄) and low spectral slope (S_275-295), compared to water entering the marshes during the flooding tide. On a seasonal scale, waters in the ebbing tide during summer and fall had elevated DOC concentrations, high absorption and aromaticity, and correspondingly lower spectral slopes relative to waters collected in winter and spring. The results of on-site incubation experiments demonstrated that photochemical degradation was the major process that removed the colored fraction from the DOM pool, whereas microbial processing played an important role in affecting the bulk DOM. This study helps improve our understanding of the dynamics of marsh DOM and the mechanisms of its degradation processes associated with lateral transport from estuarine marshes to adjacent estuaries.

Scirpus mariqueter is a pioneer and keystone species of the salt marsh ecosystem in the Yangtze River Estuary. Seeds produced via sexual reproduction are the primary means of long-distance population dispersal. This study investigated the seed production, characteristics of dormancy, and germination of S. mariqueter populations along gradients of elevation in tidal flats using field surveys, seed storage experiments, and germination tests. The results of seed production studies showed that the elevation of tidal flats significantly influenced plant density and seed production of S. mariqueter (p < 0.05). Sampling areas at an elevation of 2.8 m and above were found to have the highest plant density and seed production at (682 ± 27) ind/m² and (1724 ± 101) seeds/m², respectively. Areas between 2.5 ~ 2.8 m of elevation had a plant density of (256 ± 41) ind/m² and a seed production of (613 ± 101) seeds/m². The lowest values were observed in sampling areas between 2.0 ~ 2.5 m elevation, with a plant density of (138 ± 27) ind/m² and absence of seed production. The seed production of mature communities in suitable habitats could reach up to (1724 ± 101) seeds/m². The results of seed storage, dormancy, and germination experiments showed that the seeds of S. mariqueter matured in autumn with an inherent dormancy state. After being buried in soil seed banks, the seeds enter enforced dormancy during winter. These seeds can germinate rapidly in spring when temperature and moisture conditions in favorable habitats become suitable. However, if the seeds experience environmental stresses during this period, such as deep sedimentation or flooding, they cannot germinate and instead will re-enter induced dormancy during the high temperatures of summer. Seeds in induced dormancy require another process of vernalization to break dormancy and germinate under suitable conditions. The seeds of S. mariqueter can survive for many years after entering induced dormancy and can be placed in a persistent seed bank. The findings of this study can contribute to a deeper understanding of the characteristics of seed biology for S. mariqueter and provide an important scientific basis for the ecological restoration and reconstruction of S. mariqueter populations.

This study aimed to investigate the environmental changes in the mussel farming area of Lyuhua Island since the marine aquaculture boom in Shengsi County in 2000. Sedimentary records were established for a sediment core in the bay south of Lyuhua Island. Notably, compared to before 2000, the total nitrogen (TN) content decreased by approximately 23%, and total phosphorus (TP) content also slightly declined, suggesting a decrease in the nutrient levels in the study area. In addition, the stable isotope ratio of organic carbon (δ¹³Corg) became lighter after the year 2000, indicating a reduction in primary productivity. Combined with dating and grain size composition analysis, the sedimentary environment in this study area was relatively stable. The study area is within the influence range of the Changjiang Diluted Water. However, TN and δ¹³Corg showed a significant decreasing trend on the sediment surface. These results suggest that the decrease in nutrient levels in the study area can be primarily attributed to removing nutrients by mussel harvesting.

High-level pond aquaculture activity is common on the sandy coasts of South China. Exploring how its tailwater discharge process affects the sedimentary distribution pattern of the beach is crucial for the sustainable utilization and value-added services of coastal resources. Based on the characteristic values and distribution characteristics of surface sediment grain-size, grain composition, and grain-size parameters, this study explored the similarities and differences in grain-size distribution information between high-level pond beaches and normal beaches in the eastern part of Leizhou Peninsula, as well as the reasons behind them. The results showed that: ① the characteristic grain-sizes (D₁₀, D₅₀, and D₉₀) of normal beaches were relatively close, while the high-level pond beaches exhibited larger differences; ② normal beaches mainly contained fine, medium, and coarse sand with similar content; however, no discernable pattern in the high-level pond beach profiles was observed; ③ the range of average grain-size, sorting coefficient, skewness, and kurtosis of normal beaches were relatively close, while the high-level pond beaches exhibited larger differences; and ④ normal beaches showed a trend of finer average grain-size, better sorting, and more negative skewness from land to sea, while the profiles of the high-level pond beaches mainly exhibited a reverse trend of coarser average grain-size, poorer sorting, and more positive skewness. The intermittent discharge process of tailwater from high-altitude aquaculture and its products, as well as the topography of gullies, were the main reasons for the differences in the lateral distribution of sediment between them and the unaffected beaches. This study provides a typical case of how high-level pond aquaculture activities affect the lateral grain-size distribution characteristics of beach surface sediments, which contributes to a better understanding of the interaction mechanisms between human activities and beach sediment and geomorphic processes.

The direct discharge of high-level pond aquaculture effluent onto beaches is a common human activity along the South China coast. Investigating the mechanisms by which such activities affect the distribution patterns of beach sediment information is crucial for the sustainable utilization of coastal resources. This study explored the similarities and differences in the distribution of particle shape parameters between the beach influenced by high-level pond aquaculture and the unaffected beach, along with the reasons behind them, using characteristic values, spatial variation characteristics, and correlations among five particle shape parameters of surface sediments. The results show that: ① the characteristic values of the average particle shape parameters of the two types of beaches are relatively close; ② presence of certain differences in the spatial variation trends of aspect ratio, circularity, and convexity between the two types of beaches, amidst consistent spatial variation trends of symmetry and sphericity; and ③ the relationships between particle shape parameters and between particle shape parameters and grain size parameters in the two types of beaches were not significantly correlated. The discharge process of high-level pond aquaculture effluent and the resulting changes in gully topography alter the flow field and material distribution process of beach profiles, the primary reasons for the differences in particle shape parameters between the two types of beaches. This study provides a case study on how high-level pond aquaculture activities affect the distribution characteristics of beach sediment particle shape information. The findings contribute to a better understanding of the interaction mechanisms between marine aquaculture activities and sandy beach geomorphological processes.

In this study, two open-pit coal mine dumps in Ordos City, Inner Mongolia, namely, Shigetai and Heidaigou, were selected as research subjects. Soil physicochemical properties, structure, heavy metal pollution (assessed using a single-factor evaluation index), and their interrelationships were analyzed at each dumping site along eight directions: east, west, south, north, northeast, northwest, southeast, and southwest. The aim of this study was to elucidate the factors influencing heavy metal contamination in open-pit coal mine dumps. The results of this study can guide the selection of ecological remediation measures for mining areas based on local conditions. The results showed that: (1) There were considerable differences in soil physicochemical properties, structure, and heavy metal contamination between the Shigetai and Heidaigou mining areas. (2) Soil total phosphorus varied considerably among the different orientations in Shigetai, whereas there was a considerable difference in soil total potassium among the different orientations in Heidaigou. (3) Heavy Cd pollution was observed, and there was slight Mn pollution in Shigetai. In Heidaigou, there was heavy Cd pollution and slight Cu and Ni pollution. (4) While there was a considerable difference in the level of Cd pollution along the different directions in Shigetai, the level of Mn pollution showed no correlation with direction. There was a considerable difference in Ni pollution levels among the different orientations in Heidaigou, whereas Cd and Cu pollution levels were not related to orientation. (5) The trends in the Cd pollution levels in Shigetai and Ni in Heidaigou along the different directions were generally consistent with the changes in their topography. In other words, areas with lower topography experienced more severe heavy metal pollution. (6) Correlation analysis revealed that the level of heavy metal contamination was strongly associated with soil pH, total K content, and the proportion of large-sized soil particles. In conclusion, varying levels of heavy metal pollution were observed in the different mining dumps. Significant correlations were observed between three soil environmental factors, namely, the topography of the dump, soil fertility, soil structure, and the level of soil heavy metal pollution.

Currently, industrial enterprises primarily utilize two initial rainwater collection methods based on time (first 15 ~ 30 min) and depth (first 20 ~ 30 mm) according to the relevant specifications and standards. However, online monitoring and control of rainwater discharge water quality in chemical industrial parks is relatively weak and there is limited research on the pollution control effects of different initial rainwater collection methods. This study utilized monitoring data from rainwater outlets in a Shanghai chemical industrial park to investigate the pollution risks associated with different initial rainwater collection methods and align them with the requirements for pollution emission load control and water quality compliance. The cumulative distribution curve of the runoff pollution load was used to examine the response of key water quality indicators to rainfall. This study discusses variations in different initial rainwater collection and management methods in chemical industrial parks from the perspective of pollution reduction. Chemical companies generally adopt time-based initial rainwater collection for operational convenience during continuous heavy rainfall, with its rainwater pollution control effect being relatively limited. Therefore, it is recommended that chemical industrial parks adopt depth-based collection methods tailored to rainfall characteristics to effectively reduce rainwater pollution loads and mitigate pollution risks.

This study developed an evaluation system for urban wastewater treatment plants (WWTPs) based on Environment, Social, Governance, and Economy (ESG + E), encompassing four dimensions: environmental impact, social responsibility, corporate governance, and economic benefits. Seven detailed criteria and twenty evaluation indicators were developed accordingly. The analytic hierarchy process method and fuzzy comprehensive evaluation method were used to create the evaluation model, which was then used to evaluate the overall performance of three urban WWTPs in Shanghai. The results showed that WWTP1 and WWTP3 performed exceptionally well, while WWTP2 performed admirably. Recommendations for WWTP2 include improving resource utilization, diversifying employee training, and strengthening disclosure systems. The evaluation results were consistent with the WWTPs’ actual operational status, demonstrating the accuracy and scientificity of the evaluation system. This study provides a useful reference for the performance evaluation of urban WWTPs.

Owing to the tidal dynamic inundation, the vegetation information of low cover saltmarsh located at the front of tidal flat and edge of tidal ditch in the estuarine and coastal area is difficult to accurately extract using common terrestrial vegetation indices. This study considered the tidal flat wetland in the Yangtze River Estuary as research area. Based on the comparison and evaluation of commonly used terrestrial vegetation indices, combined with the humidity index, a vegetation index ETFVI (Estuarine Tidal Flat Vegetation Index) suitable for the intended region was developed. The accuracy of the extracted vegetation distribution information and the inverted fractional vegetation cover results was verified. The results suggested that, compared with the commonly used eight vegetation indices, ETFVI improved the extraction accuracy and F₁ score of vegetation distribution information by 10.38% and 6.9%, respectively, compared to the second place considering the impact of humidity changes of underlying surface on vegetation indices. The fractional vegetation cover inversion results based on ETFVI are consistent with the actual situation, with the lowest mean relative error among various vegetation indices. The study results can provide new ideas and methods for monitoring spatiotemporal changes of vegetation cover in estuarine tidal wetlands.

The measurement errors of particulate carbon and nitrogen in water using three pretreatments were evaluated quantitatively, and impact factors were discussed. Next, an optimized sample collection, pretreatment, and measurement method was suggested. The results showed that the measurement errors of samples analyzed on whole filters were the lowest, and those of samples pretreated by scraping were the highest. The measurement errors of carbon were lower than those of nitrogen and were negatively related to the carbon content on the filter (r = –0.545, p = 0.000). When the carbon content on the filter was > 0.5 mg, the measurement error of the carbon was < 10%. When the carbon content on the filter reached 1 mg, the measurement error could be < 5%. In conclusion, the predominant factors influencing the measurement error were the carbon content, uniformity of the particulate, and sample residue on the filter. The results suggested that more complicated factors influenced the measurement of nitrogen content. An optimized method for the sample collection, pretreatment, and measurement was recommended, namely, a smaller glass microfiber filter (GF/F: diameter 25 mm) should be used to collect the samples, the whole filter should be analyzed without cutting and scraping pretreatment, and the carbon content of the particulate matter on the filter should be > 0.5 mg.