Purification mechanism of emergent aquatic plants on polluted water: A review

Nitrogen and phosphorus inputs to surface water bodies lead to a decline in water quality and a disruption in the balance of aquatic ecosystems. Emergent aquatic plants were widely used for their high efficiency in removing nitrogen and phosphorus from surface waters. However, there was a lack of systematic analyses on the purification of surface waters by emergent aquatic plants, and the mechanism of differences in nitrogen and phosphorus removal by different plants needs to be further revealed. By preferentially selecting emergent aquatic plants, the removal effects of 15 selected aquatic plants on five pollutant indicators (total nitrogen, ammonia nitrogen, nitrate nitrogen, total phosphorus, and chemical oxygen demand) were analyzed at different concentrations, and the characteristics of the removal of pollutants by different aquatic plants were explored. At the same time, combined with the morphology and synergistic action of microorganisms, in-depth research on the purification mechanism of water bodies by emergent aquatic plants was conducted. Differences were found in the purification of different water-supporting aquatic plants for different concentrations of pollutants. The comprehensive evaluation results of the membership function showed that the combined purification ability of Acorus calamus, Cyperus involucratus, Iris pseudacorus and Typha orientalis was better for the conventional pollutants. This study provides an important reference for the preferential selection of emergent aquatic plants to enhance water pollution purification and further promote the progress of ecological water treatment technology.