Comprehensive Management of Rural Water Pollution in Polder Wetland: a Case Study of the Chenhai Wei Polder Wetland in the Taihu Basin of China

Abstract

Polder area water systems are closed, and the farmland, villages, fish ponds, forests, river networks, and other features are all intertwined. This causes water pollution in polder wetland to be characterized by a poor self-purification ability due to the closed system and a short pollutant residence time. This study utilizes Chenhai Wei polder wetland in Taihu Basin of China as an example to construct a multi-level pollution comprehensive management system using ecological ponds, grass-growing ditches, aquatic plants, aquatic crops, ecological floating beds, etc. This system achieved its purpose of prolonging the pollutant residence time and enhancing self-purification ability of rivers in polder wetland. In addition, due to the importance of localized agricultural production, a three-level system that combines farmland production, ecological pond planting, and river surface planting was established that fully utilizes nutrients and purifies the water while generating economic benefits. Three years after construction, the total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH+ 4-N), and chemical oxygen demand (CODcr) of the river water were significantly reduced (P < 0.05). The total removal was much larger than the total production amount, which effectively protects the regional environment and enables the sustainable development of production and life in the polder wetland.This study of rural water pollution management in the Chenhai Wei polder wetland and the integration of this effective localized technological system provides a reference for similar regions.