The Research of Purification Effect of Eutrophic Water by Java Waterdropwort, Oenanthe javanica
水芹对富营养化水体的净化效果研究

Java waterdropwort (Oenanthe javanica) were planted in Expandable polyethylene boards, to detect the purification effect on eutrophic water at 4 different levels. The results showed that Java waterdropwort had a high ability to remove total phosphorus (TP), and the water with higher initial concentration had a lower removal rate. The removal rates of TP ranged from 53.3% to 84.0%. Java waterdropwort had a high ability to remove total nitrogen (TN) when the concentration of water was lower than 5mg/L. The groups with higher initial concentration of TN also had a low removal rates. The removal rates of TN ranged from 36.1% to 85.7%. There was almost no purification effect when the concentration higher than 20mg/L. Although concentrations of ammonia nitrogen(NH3-N) in treatment groups decreased obviously, and there was no advantage compared to the control. Java waterdropwort had few purification effects on the concentration of nitrous nitrogen(NO2-N). Nitrobacteria played an important role in the removal of ammonia nitrogen and nitrous nitrogen. Java waterdropwort could remove ammonia nitrogen and nitrous nitrogen indirectly through the decrease of total nitrogen. The permanganate index kept at a low level (<3mg/L) during the whole experiment period, the removal effect of permanganate index had not been observed.