Study On Aquatic Phytoremediation For Improving Water Quality Of Yanghe Reservoir

Yanghe Reservoir is the most important water resource of Qing Huangdao City and Bei Daihe Borough. As a transferred reservoir, it is also in charge with assignment transferring about 0.06 billion tons drinking water every year from Tao Linkou Reservoir to Qing Huangdao City. But the water quality of Yanghe Reservoir had become deteriorated in recent years. There was low transparence, turbid and fishy water in the reservoir and it had been an eutrophicated reservoir. That could cause some serious problems: polluted water could not be used as the drinking water and daily used water for denizen, and it also destroyed the development of economy of Qing Huangdao City severely.The aquatic phytoremediation was used to improve the water quality of the reservoir. The effect of purification for contaminations by planting aquatic macrophytes, compositive purification effect of aquatic macrophytes complex system and how the aquatic macrophytes work on the quantity decrease of nitrogen and phosphorus in sediments were studied in this test. Because of the long periods of biologic test, the results were only segmentaland they were concluded as follow:1. It could be seen from the results that the aquatic macrophytes selected in this test improved the concentration of DO in water, decomposed contaminations effectively. As to the purification effect of single kind aquatic macrophyte it could be concluded that submerged hydrophytes (Ceratophyll umdemersum Linn, Hydrilla verticillata Royle, P. malaianus Miq.) had the best removal ratios for contaminations; emergent hydrophytes (Phragmitis communis T., Typha latifolia L., Acorus Calamus L.) had the worst reversely; and the removal ratios of floating hydrophytes (Eichhornia crassipes, trapa japonica, Nymphaea linn.Sp.) were between them. Meantime the biomass of algaes in planted enclosures was less than in unplanted enclosure obviously. So the quantity of alages could be restrained by planting aquatic macrophytes.2. During the dynamic test, complex system was constructed to study compositive purification effect of aquatic macrophytes. The results showed that with the different hydraulic remain time (HRT) the eutrophic water could be purified and the transparency of the water improved effectively as it passed though the complex system. It could be shown at the test sit that there were floccules on the stems and leaves surface of aquatic macrophytes, so that aquatic macrophytes could adsorb the alages and granule contaminations in the whole passed water, and this was a reason...