[Purification Effect of Submerged Macrophyte System with Different Plants Combinations and C/N Ratios].

system were different. The removal efficiency was highest when the C/N ratio was 5.93, with removal rates for total nitrogen and total phosphorus and a reduction in permanganate index of 81.34%, 68.26%, and 88.65%, respectively. The C/N ratio affected the degradation of nitrogen, phosphorus, and organic matter by influencing the dissolved oxygen concentration of water and changing the anaerobic and aerobic environment of the water. In conclusion, different submerged macrophyte combinations showed better purification effect than a single type of plant in the submerged plant pond system. Changing the influent C/N ratio by placing carbon source materials into the water can greatly increase the removal efficiency of submerged plant pond, providing a practical reference for the use of submerged plant ponds to treat sewage.