Abstract:To explore purification capacity of heavy metals and nutrients in plant technology facilities of river course of a sponge city, Jiangxinzhou in Nanjing ecological science and technology island was selected as research object, contents of heavy metals and nutrients in upstream and downstream water were determined. Risk of heavy metals in upstream and downstream water was evaluated by comprehensive pollution index method. Redundancy analysis and spearman correlation coefficient were used to explore impact of water environmental factors on heavy metal content. Four plant technology facilities (riparian buffer zone, vegetation filter belt, ecological floating island and platform type gabion revetment) were used to explore purification capacity of different plants combinations for pollutants in water. The results show that WQI values of heavy metals in upstream water of river course in dry season, wet season and normal season are 1.85, 1.74 and 2.90, respectively, corresponding to light pollution, mild pollution and moderate pollution. However, WQI values of heavy metals in dry season, high flow period and normal water period are 0.18, 0.30 and 0.52, respectively, exhibiting no pollution in downstream water of river course. pH value is the most important factor affecting content of heavy metals in upstream water of course. pH value is insignificantly positive correlation with dissolved oxygen (DO), total nitrogen (TN), five-day chemical oxygen demand (COD5) and total phosphorus (TP). pH value of downstream water of river course is also the most important environmental factor affecting content of heavy metals in water, and it is significantly positively correlated with dissolved oxygen (DO). Purification capacity of nutrients in water body is riparian buffer zone > vegetation filter belt > ecological floating island > platform type gabion revetment. Compared with other plant combinations, arbor and shrub community have the highest potential for nutrient purification in water.