| Summary: | 碩士 === 國立臺北科技大學 === 土木工程系土木與防災碩士班 === 106 === The technology of water treatment is well-developing in Taiwan. The quantity of the wastewater treatment plants is also increasing. However, these plants focus on the point source pollution treatment, such as municipal wastewater and industrial wastewater. The non-point source pollution- agricultural wastewater, is out of the treat range of the wastewater treatment plants. Its pollution spreads with river flow, surface runoff and soils, and not along with the pipes lead to treatment plants.
Multi-soil-layering System, which is original invented in Japan, is one of the natural treatment system. It uses natural materials, and less costs of money and operation area than traditional natural treatment system. It has high purifying effect on many types of pollution, proved to be a great method in ecological engineering. Bioretention Cells is one of the Low-Impact Development Installation, which has the ability to mitigate the strength of stormwater and the runoff following.
This research study about the combine installation of MSL and Bioretenton, and design an experiment about three levels of concentration of pollution (contained phosphorus, nitrogen and COD) and four levels of rainfall strength, to analyze the removal rates of traditional bioretention and the MSL-applied bioretention, separately.
The result shows that the MSL-applied bioretention has overwhelming greater effect in reducing phosphorus, especially when greater rainfall and higher concentration. The phosphorus purifing rate of MSL-applied bioretention in this experiment has more than 80% at all time, not affected by strong rainfall. The outflow concentration of two installations are almost double. As for nitrogen, the effect gap between MSL-applied and traditional bioretention is not as deep as phosphorus at all rainfall situation. As for COD, because of unstable microbes and biofilm, MSL-applied bioretention is only better than traditional bioretention when the rainfall strength is weak. when the rainfall strength stronger, the outflow concentration of two installations are near.
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