Identificationand Optimization Of Plants For Landscape Water Biorestoration

Landscape water is becoming more and more common. The amount ofresidential quarters, gardens and cities with waterscape is increasing, following thedevelopment of the society and the improvement of people’s life. However, waterquality of landscapes is declining because of contamination. In some places,landscape water starts to produce uncomfortable odor and dark color, withincreasing death of ornamental fish, which make it urging to solve the issue oflandscape water eutrophication.Landscape water of a botanic park in a city in south China is selected for theresearch. Study on inhibition of algae is carried in the light of the mechanism ofallelopathic algal suppression of aquatic plants. Compared with microbial algalsuppression, allelopathic algal suppression can ensure the safety of aquaticecosystem and protect human bodies, with no secondary–pollution and costs less,while the efficiency can be much higher. Therefore, studies on algal suppression ofemerged plants and submerged plants can set theoretical and practical basis forallelopathic mechanism between aquatic plants and floating algae and therestoration of emerged and submerged plants for water with eutrophication.Methods used in this research on allelopathic algae suppression of emergedand submerged plants are described as follow. First, comprehensive comparison ofvisual effect between10species of submerged plants is conveyed. Myriophyllummetogrossense “green” showed the best algal suppression in the comparison ofgrowth and removal of nitrogen, phosphorus, Chorophyta and Bacillariophyta, andis determined to be the superior of submerged plants. Afterwards, four emergedplants, Iris germanica, Cyperus alternifolius, Canna and Lythrum salicarie, are co-cultured with Myriophyllum metogrossense “green”. Comparisons of visual effect,growth and removal of nitrogen, phosphorus, Chorophyta and Bacillariophytaindicate the best algal suppression of co-culture of Lythrum salicaric andMyriophyllum metogrossense “green”, which can be used as the model plants foralgal suppression project of water ecosystem in botanic park. Finally, optimalarrangement of cultivating of aquatic plants for restoration of polluted landscapewater is provided, followed by selection and arrangement of the species of plants,as with configuration tables and methods in detail.GC-MS analysis for blank sample and the water sample of co-culture ofMyriophyllum metogrossense “green” and Rotala wallichii shows that6compounds,namely Diisobutyl phthalate, Squalene, Isophorone,4’-Chloroacetanilide, o-Chloroaniline and Pyrazole, are found in the water sample of Rotala wallichii, and4compounds, namely p-o-Toluidine,4-(3-Pentyl)pyridine, Anthraquinone and6-Methylphenanthridine, are found in water sample of Myriophyllum metogrossense “green”, which are considered to be potential allelopathic substrate causing algaesuppression.According to the research above, ecological restoration of eutrophication oflandscape water through allelopathic algae suppression of aquatic plants is carriedout, which has achieved the expected efficiency.