Treating carbon-limited wastewater by DWTR and woodchip augmented floating constructed wetlands

• DOI: 10.1016/j.chemosphere.2021.131331
• Publication Date: 2021-06-26T15:33:09Z
• Authors: Cheng Shen; Yaqian Zhao; Yan Li; Ranbin Liu; Jie Wang; Yan Yang
• Keywords: Nitrogen; 13. Climate action; Wetlands; 0211 other engineering and technologies; Phosphorus; 02 engineering and technology; Wastewater; Waste Disposal, Fluid; Carbon; 6. Clean water; Water Purification

Floating constructed wetlands (FCWs) have attained tremendous popularity for water purification purposes. However, FCW functions establishment in nutrients removal from carbon-limited wastewater, especially in cold weather, is still a challenge. Here, two drinking water treatment residual (DWTR) based biocarriers (B-I: DWTR cakes, B-II: DWTR cakes combined with woodchips) have been augmented into FCW to enhance the nutrients (N and P) removal performance. Compared to the traditional FCW, the intensified FCWs simultaneously achieved higher N and P removal efficiencies, with average pollutants removal of 52.16 ± 11.51% for TN and 92.72 ± 1.61% for TP in FCW-I and 57.65 ± 9.43% for TN and 92.17 ± 2.55% for TP in FCW-II, respectively, while their removal in FCW-III of 27.74 ± 7.11% for TN and 17.91 ± 9.27% for TP. B-II performed best in overcoming the negative influence of low temperature in nutrients removal. Mass balance budget indicated that most P was enriched in DWTR based biocarriers. Thus it is feasible to recycle and recover P from the surface water. Furthermore, P in the sediment can be changed from active P to stable P, mitigating the internal P release risk. This study can help to expand the understanding of the intensified FCWs and promote the practical application of FCWs.