Research On Purification Efficiency Of The Eutrophic Water By Water Cycling-aerator System, Wave-conveying System And Ecological Floating Bed System

The compound ecological floating bed system is based on the inflatable planting plate with five plants such as Canna indica. Acorus calamus Linn, Oryza. Saliva L. Thalia dealbata and Lythrum salicaria Lin, and the collocation with water cycling-aerator equipment and wave-conveying equipment for restoring the eutrophic water. In this paper, a series of studies on the restoration efficiency have been carried out by using the method of compound ecological floating bed system to restore the eutrophic water, and the change of nitrogen and phosphorus content of sediment during the test. In addition, not only the growth situation of the5plants, but also the relationship between plant biomass and nitrogen and phosphorus absorption ability were investigated. The main results and conclusions are reported as follows:1. The compound ecological floating bed integrates plant floating bed, water cycling-aerator equipment and wave-conveying equipment. Under the test conditions, the water quality of purification pool was obviously improved. The contents of TN, TP. NH4+-N, NO3--N, CODMn decreased by67.50%,65.22%,59.00%,53.70%and51.20%, respectively, which was much higher than the water self-purification removal rate of the blank control pool.2. There are obvious correlations between Chla with SD, TN, NH4+-N, NO3--N, CODMn and TP. Chla and SD have significant negative correlation, and other water quality factors are significant positive correlation with Chla. The correlation coefficient of TN and Chla reached0.994. which was the highest of all factors.3. During the test. TN. NH4+-N, NO3--N contents of sediment in processing pool presented a downward trend, and the removal rates were28.02%,21.66%and15.38%, respectively. While in the black control pool. TN, NH4+-N, NO3--N contents increased by15.40%.10.61%and11.26%. respectively. Apparently, the compound ecological floating bed has the function of the removal of pollutants in both water and sediment at the same time.TP and Ads-P contents of sediment showed opposite change trends. After test, TP content of sediment in processing pool increased by10.95%. And in the blank control pool，the content of TP was reduced by4.13%with respect to the initial value. In contrast, the content of Ads-P of sediment in processing pool decreased by25.85%, but increased by18.42%in the blank control pool.4. During the test, plants grew well and reproduced by constantly tillering. Canna indica has the maximum number of tillers, and the next order is Thalia de alb at a>Ly thrum salicaria Lin>Acorus calamus Linn>O. Sativa L. In the early period of the test, O. Sativa L and Lythrum salicaria Lin tillered rapid, while in the later stage, Canna indica and Thalia dealbata had stronger tiller capability than other plants.5. The distribution of nitrogen and phosphorus contents in five plants are different. Total nitrogen of plants are Acorus Calamus Linn>Canna indica>Lythrum salicaria Lin>O. Sativa L>Thalia dealbata. And total phosphorus are Canna indica> Acorus calamus Linn>Lythrum salicaria Lin>O. Sativa L>Thalia dealbata. Compared with different plant tissues, both in Canna indica and Thalia dealbata, the content of TN and TP in shoots were higher than that in roots. However, it was an inverse distribution in Acorus calamus Linn and Lythrum salicaria Lin. There were more nitrogen and less phosphorus in root of Oryza. Sativa L than in shoot.The absorption ability of nitrogen and phosphorus by Canna indica and Thalia dealbata were stronger than Acorus calamus Linn, Oryza. Sativa L and Lythrum salicaria Lin. Among those plants, Canna indica had the strongest absorption capacity of nitrogen, achieved53.85gram per plant. And for phosphorus. Thalia dealbata had the highest removal efficiency, achieved4.49gram per plant. The absorption ability of nitrogen of shoot were2.77times and1.86times as much as that of root in Canna indica and Thalia dealbata, respectively. And the phosphorus absorption content of shoot were1.84times and1.14times as much as that of root, respectively. It is definitely that reaping the shoots can wipe out a large proportion of the nitrogen and phosphorus in water.