Removal efficacy of fly ash composite filler on tailwater nitrogen and phosphorus and its application in constructed wetlands

Shuhang Wang; Haoran Yang; Feifei Che; Wei Huang; Dianhai Yang

doi:10.3389/fchem.2023.1160489

Removal efficacy of fly ash composite filler on tailwater nitrogen and phosphorus and its application in constructed wetlands

Front Chem. 2023 Apr 19:11:1160489. doi: 10.3389/fchem.2023.1160489. eCollection 2023.

Authors

Shuhang Wang^{1

2

3}, Haoran Yang², Feifei Che³, Wei Huang^{2

3}, Dianhai Yang¹

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China.
² State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, China.
³ National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Institute of Lake Environment and Ecology, Chinese Research Academy of Environmental Sciences, Beijing, China.

Abstract

Constructed wetlands (CWs) have been widely used in tailwater treatment. However, it is difficult to achieve considerable removal efficiency of nitrogen and phosphorus in tailwater solely by CWs-an efficient green wetland filler is also important. This study investigated 160 domestic sewage treatment facilities (DSTFs) in rural areas from two urban areas in Jiaxing for TP and NH₃-N and found that TP and NH₃-N concentrations in rural domestic sewage (RDS) in this plain river network are still high. Therefore, we selected a new synthetic filler (FA-SFe) to enhance nitrogen and phosphorus reduction, and we discuss the importance of filler in constructed wetlands. Experiments revealed the adsorption capacity of the new filler: the maximum adsorption amounts of TP and NH₃-N reached 0.47 g m^-2 d^-1 and 0.91 g m^-2 d^-1, respectively. The application potential of FA-SFe was verified in actual wastewater treatment, with the removal rates of ammonia nitrogen and TP reaching 71.3% and 62.7%, respectively. This study provides a promising pathway for nitrogen and phosphorus removal from rural tailwaters.

Keywords: constructed wetlands; filler; nitrogen removal; phosphorus removal; tailwater.

Grants and funding

This study was supported by the National Natural Science Foundation (52000024, 41907335), the Shanghai Sailing Program (20YF1400300), and the Fundamental Research Funds for the Central Universities.