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Nutrients carried in upstream rivers to lakes are the main cause of eutrophication. Building near-natural estuarine wetlands between rivers and lakes is an effective way to remove pollutants and restore the ecology of estuarine areas. However, for the existing estuarine wetland ecological restoration projects, there is a lack of corresponding evaluation methods and index systems to make a comprehensive assessment of their restoration effects. By summarizing a large amount of literature and doing field research, an index system was constructed by combining the characteristics of the near-natural estuarine wetlands themselves. It covered environmental benefits, technical management and maintenance, and socio-economic functions, and contained 3 systems, 7 criteria, and 16 indicators. The analytical hierarchy process (AHP) was used to determine the weights of each indicator. The top 5 indicators in order of importance were habitat diversity, total phosphorus (TP), coverage of aquatic plants, ammonia nitrogen (NH3-N), and adaptation to the surrounding landscape. The above evaluation system was used for the comprehensive evaluation of the water purification project in the Fuhe estuarine wetland, Hebei Province, as an example. The results showed that the comprehensive score of the Fuhe estuarine wetland at this stage was 4.1492, and the evaluation grade was excellent. The effect of water purification and ecological restoration was good, and the selected technology was suitable and stable in operation. It had a greater positive impact on the surrounding economy and society and can be promoted and applied. The research results were important for clarifying the advantages and defects of the project and developing efficient and advanced restoration technologies.

The estuarine wetland buffer zone of the Fuhe river plays an important role in terms of improving water quality of Baiyangdian lake. In this study, the water purification effect and microbial community composition of an estuarine wetland buffer zone during a low-temperature period were investigated (March, 2021). The results indicated that the pre-sedimentation ecological pond (Pep), the subsurface flow wetland (Sfw), and the aquatic plant pond (App) exhibited good removal effects on total phosphorus (TP) and NH3-N. In contrast, the removal effects on chemical oxygen demand (COD) and total nitrogen (TN) was unsatisfied. Various phosphorus removal bacteria were detected in the water samples from the Pep and the Sfw, such as Arthrobacter, Flavobacterium, and Planococcus. These findings indicated the water purification performance and the microbial community composition in an estuarine wetland buffer zone during a low-temperature period.

Water shortage severely restricts vegetation restoration of mining area in the northwest China. Moderate treatment of reclaimed water is essential for improving the local ecological environment. In this study, relevant water quality standards issued by the states and research results were comprehensively considered to propose a reclaimed water quality standard suitable for vegetation restoration of mining area. The available domestic sewage and mine water was moderately treated by hybrid biological reactor system and nanofiltration membrane system, respectively. The effluent quality meet the requirement of reclaimed water quality standards in this study. This study provides theoretical support for vegetation restoration of mining area.

As a national key protection and restoration project, ecological restoration of Baiyangdian Wetland has an important significance for environmental management. As the research area in Zaozhadian wetland, the purification effect of warm season and cold season aquatic plants was studied under different overflying water qualities. It provides a theoretical and experimental basis for the ecological environment restoration and management of wetlands. The results showed that the warm season and cold season aquatic plants all played important roles on the nitrogen and phosphorus removal and maintained the stable water environmental from the nutrient release from soil. The warm season plant-mixed Myriophyllum spicatum and Ceratophyllum demersum and the cold season plant-Potamogeton crispus L. can be reasonably configurated for the wetland restoration.