In the present study, the performance of a circular flow constructed wetland (CFCW)¹ system was assessed for organics and total phosphorus removal from fertilizer plant effluent. The CFCW system has five media compartments containing gravel, slag iron, and a mixture of sand and zeolite as the media substrates. Synthetic fertilizer wastewater having initial COD 520.98 ± 8.27 mg/L, was fed to the wetland, maintaining hydraulic loading rate of 6.945 L/m²-h. Typha angustifolia was used as the wetland vegetation. The Phase 1 of the study included three cycles, with influent phosphorus concentrations 10, 20, and 30 mg/L, respectively without step feeding and effluent recirculation. The Phase 2 of the study included two cycles with influent phosphorus concentrations of 20 and 30 mg/L, and application of step feeding and effluent recirculation strategies. The average phosphorus removal efficiencies of the system in three cycles of Phase 1 were 85.16 %, 88 %, and 81.95 %, respectively, along with average COD removal of 87.48 %, 87.65 %, and 86.84 %, respectively. The average phosphorus removal efficiencies of the system in two cycles of Phase 2 were 89.01 % and 90.22 % respectively, along with average COD removal of 91.6 % and 91.23 %, respectively. The step feeding and effluent recirculation strategies have shown satisfactory improvement in organics and total phosphorus removal performance of the CFCW system. However, future long-term studies are recommended involving an unplanted control system, step feeding and effluent recirculation in varying compartments, and varying combination of media substrates for improving the design and performance of the CFCW systems.

在本研究中，对循环流人工湿地 (CFCW) ¹系统的性能进行了评估，以从化肥厂流出物中去除有机物和总磷。CFCW 系统有五个介质隔间，其中包含砾石、渣铁以及作为介质基质的沙子和沸石的混合物。将初始 COD 为 520.98 ± 8.27 mg/L 的合成肥料废水送入湿地，保持 6.945 L/m ² -h 的水力负荷率。香蒲被用作湿地植被。研究的第一阶段包括三个循环，进水磷浓度分别为 10、20 和 30 mg/L，没有分步进料和出水再循环。该研究的第 2 阶段包括两个循环，进水磷浓度分别为 20 和 30 mg/L，并应用分步进料和出水再循环策略。第一阶段三个循环系统的平均除磷效率分别为85.16%、88%和81.95%，平均COD去除率分别为87.48%、87.65%和86.84%。第二阶段两个循环系统的平均除磷效率分别为89.01%和90.22%，平均COD去除率分别为91.6%和91.23%。分步进料和出水再循环策略在 CFCW 系统的有机物和总磷去除性能方面表现出令人满意的改善。然而，建议未来的长期研究涉及未种植的控制系统、不同隔间中的分步进料和污水再循环，以及不同的介质基质组合，以改进 CFCW 系统的设计和性能。