Preliminary Study on the Clearance Mechanism of Nitrogen and Phosphorus Polluted Water by Iris -- Taking the Shichuan River as Example

The hydroponic study was used to research the effect of the iris on the removal of N and P in water, and the change of nitrogen and phosphorus in plants. The results showed that at the end of the experiment, J2 (N2P1) treated the height of the plant with the largest height of 81.1 cm; followed by J9 (N3P2) treatment, which was 75.0 cm. The J9 treated iris has the highest nitrogen content of 0.731%. And with the increase of nitrogen dosage, the nitrogen content of the leaves increased. The amount of phosphorus in the dry matter of the iris leaves ranged from 0.311% to 0.501%. The clearance rates of the three different concentrations of N were 63.5%, 67.5% and 70.2%, respectively. The clearance rates of three concentrations of P were 43.0%, 52.9% and 62.1%. When the test was carried out for 14 days, the NH₄ ⁺-N elimination rate reached 79.0%; the NH₄ ⁺-N clearance rate of J9 reached 81.0%, which was significantly higher than other treatments. At the end of the experiment, the elimination rate of NO₃ ⁻-N in water reached 16.4%, and J9 was the highest, reaching 27.4%, which was significantly higher than other treatments. According to the comprehensive analysis, the iris of J9 grew well, and the effect of purifying nitrogen and phosphorus was better. (paper)