Test Of Polishing Taihu Tributary With Micro-nanometer Aerated Floating Bed

Taihu basin is one of the most developed areas in China. Because of the excess consumption of resources and severe environmental pollution, the ecological environment has been rapid deteriorated, especially water pollution and eutrophication are serious in this region. At present, the serious pollution of rural tributaries has become important reason for the pollution of Taihu basin. According to the characteristic of pollution water, effects of micro-nanometer aerated floating bed on purifying rural tributaries were studied. The content of this paper were as follow.(1)The selection of ecological floating-bed plant.(2) By parallel comparative test to air blow aeration, the effects and regulations of micro-nanobubble aerated floating bed on purifying water.(3)The effects of micro-nanometer aerated plant floating bed on purifying water at different time of intermittent aeration.The main results are as follows:(1)In order to research on purification efficiency of the different floating beds, Acorus calamus, Iris wilsonii, Sagittaria trifolia var. sinensis, Thalia dealbata, Canna indica, and Canna warscewiezii were researched and they were chosen as research objects based on the comprehensive understand of hydrophytes in JiangSu regions of China. Results showed that the adaptability and purification efficiency of different plants were different. The Thalia dealbata had the best growth state, and it was higher than other plants on the purification efficiency of wastewater.But the removal of ammonia nitrogen with Thalia dealbata was lower than that with Canna warscewiezii.(2)The effects and regulations of different aeration technologies on the system of Thalia dealbata floating bed were studied in the present experiment with intermittent aeration. Three groups were included according to different aeration method, namely, micro-nanometer aerated floating bed, air blow aerated floating bed and non-aerated floating bed (the control group). The results showed that micro-nanometer aeration had higher ability than air blow aeration in increasing DO, and it changed micro environment of rhizosphere, which was beneficial to the growth of ammonifying bacterial and nitrifying bacteria in rhizosphere, but was harmful to the growth of the denitrifying bacteria. According to the analysis, the effects of water purification changed with time in the initial stage, while the treatment effect had no significantly change after12days.(3) The effects of micro-nanometer aerated plant floating bed on purifying water were studied at different time of intermittent aeration.The results showed that, the removal efficiency of CODMn, TN and TP were best with the micro-nanometer aerated floating bed, when the intermittent aeration time was4h.