A Preliminary Study on A Novel Water Treatment Pond Design Using Dredged Sediment, Shrub Willow and Recycling Hand Pumps for the Restoration of Water Pollution

The treatment of polluted water and sediment often costs too much and has little benefit. In this study, we proposed a novel design using dredged sediment, shrub willow (Salix spp.) and recirculating hand pumps for the restoration of polluted river water in Changchun city, China. Sediment was filled as a matrix for plant growth, shrub willow was transplanted for the absorption of nutrients, and ten hand-pumped water wells were built for recycling the polluted water. During the 5-month experimental period, the shrub willow growth and nutrient contents, sediment nutrient concentration and water quality were measured. The results showed that this pond system could effectively decrease the sediment pollutant levels, and its removal efficiencies of organic matter (OM), total nitrogen (TN) and total phosphorus (TP) could respectively reach as high as 11%, 10% and 26%. The dissolved oxygen (DO) content increased by more than 90% in August, and the chemical oxygen demand (COD) and total nitrogen (TN) content decreased by 44.93% and 19.82%, respectively. This means that the treatment pond could efficiently work toward the purification of polluted river water. The benefits and feasibility of this system application were also analyzed, and we found that it could be widely used for the treatment of polluted water and sediment in urban areas