The Study Of Water Environment And Ultrasound Algae Removal And Inhibition Technology In Pengxi River

The Three Gorges Reservoir Area has many tributaries, since the Three Gorges reservoir began to sluice in second time, part of tributaries of the Three Gorges Reservoir Area appear the phenomenon with different degrees of "water bloom" many times. The occurrence of water bloom is a complex and gradual process. So, in the prophase of the water bloom, making the appropriate preventive measures is significant to reduce the degree of eutropHication and the possibility of water bloom.A correlation of seasonal variation of water quality in Pengxi was analyzed, sought to alert the outbreak of water bloom in the basin. In addition, effect of the inhibition by ultrasonic was studied systematically and the ultrasound algae inhibition and removal of multi-functional mobile platform was established, aiming at algal bloom of Pengxi River, simultaneously a pilot was launched to evaluated the effect of the platform in the experimental site. Finally, algal removal theory and economic of multi-functional platform was analyzed to evaluate the possibility of its demonstration and extension.Ultrasound can inhibit the growth of algae, the effect of low-frequency 20-50 kHz is the best in Pengxi River to the inhibition of algae. With the irradiation time extend, the effect trends to saturation, the best duration time is 5min. The changed biomass of optimal condition(△Y 5) and the control group(△Y 0) every day meet the exponential relationship: y 0 = 0.2911x1.0283, R~2 = 0.9771. Chlorophyll a increased with cell density, there is a consistency when they were treated by ultrasound.The ultrasound algae inhibition and removal of multi-functional mobile platform was established for the characteristics of the algae in Pengxi River. And effect on the immediate removal of algae by ultrasonic irradiation time, frequency and distance was studied. In this process, response surface methodology was employed to optimize the various factors. The results show that frequency=20-50 kHz, distance=0.5m, duration time= 5min was the best single-frequency conditions for the removal of algae. The effect of chloropHyll has a certain lag, when the exposure time extends to 7min, it can achieve the best removal conditions. In this condition, removal of algae and chloropHyll a has got a increasing in varying degrees after treated by synergies with the same frequency, but the handling of the economic costs have increased.Ultrasound algae inhibition and removal of multi-functional mobile platform has a low power and the running costs are much less than other processing techniques. At the same time, ultrasound technology can effectively inhibit algal bloom with no side effects and secondary pollution will not happen to aquatic ecosystems too. Daily management and running costs are not high, the actual operating costs are 0.35yuan/10~2×m~2 or so, which has strong governance applicability to secondary rivers in the entire Three Gorges Area.