Abstract: We investigated the purification effects of subsurface wetlands, enhanced wetlands and ecological lakes on reclaimed water, as well as the variations of rotifer community structure. From February 2024 to February 2025, water quality monitoring and rotifer species identification were conducted in reclaimed water bodies of a park in Wuhu City. The results showed that compared to that in subsurface flow wetlands and enhanced wetlands, the dissolved oxygen and chlorophyll-a content in ecological lakes increased, the total nitrogen content decreased, and the diversity indices of rotifer communities increased. Throughout the year, a total of 48 rotifer species belonging to 18 genera were identified, with Polyarthra dolichoptera being the first dominant species, followed by Trichocerca pusilla, Keratella cochlearis, Polyarthra euryptera, and Brachionus calyciflorus. The evaluation results of the rotifer trophic state indices (TSI_ROT) and the eutrophication index (EI) showed strong consistency in summer and autumn seasons, but there were differences in winter and spring seasons, indicating seasonal feasibility issue in their application. The rotifer abundance had the highest positive correlation with total nitrogen, followed by temperature and chlorophyll-a, and showed a significant negative correlation with electrical conductivity. Our results provide data to support studies on the structural changes in plankton communities in water bodies replenished with reclaimed water, and offer a scientific basis for the better utilization of reclaimed water.

Key words: reclaimed water, water quality indicator, rotifer, community structure, trophic state index