Integration of ecological restoration and landscape aesthetics: Mechanisms of microplastic retention by optimization of aquatic plants landscape design in urban constructed wetlands - A case study of the living water park in Chengdu.

Microplastic (MP) pollution is prevalent in urban water environments, with increasing evidence of its negative environmental impacts. This study examines the role and mechanisms of aquatic plant landscapes in the ecological remediation of MP (0.05-5 mm) in urban constructed wetland parks, using the Living Water Park in Chengdu as a case study. Over a period of two years, a systematic investigation of MP characteristics, abundance and distribution in the water environment as well as aquatic plant landscapes in the park. Sampling was carried out for the three stages of the Fuhe River before, during and after its flow through the park, and for the water bodies at each step of the water purification system within the Living Water Park, and a total of 66 samples of freshwater microplastics (MPs)were collected at 8 preliminary and 25 official sampling sites selected. MPs were observed in all samples, with higher abundance found in more close-to-natural areas, such as ecological wetlands and streams. Aquatic plants play a crucial role in MP remediation through adsorption, uptake (Mp ≤ 5 μm) and accumulation. A positive correlation was found between MP abundance, aquatic plant species diversity, and public landscape evaluation. More diverse and layered wetland plant configurations exhibited better MP remediation capabilities. The study suggests specific aquatic plant species and combinations for optimal MP remediation, emphasizing the importance and feasibility of aquatic plant landscapes in urban constructed wetland parks. The findings highlight the potential of urban constructed wetland parks for MP remediation and provide important doi:ces for their long-term development and landscape design, proposing strategies from plant combination optimization to integrated landscape design and maintenance.