Study on the biomanipulation efficiency to reduce the algae for water quality improvement at the Drunken Moon Lake, NTU

• Main Authors: SHIH-CHI TSAI, 蔡世麒
• Other Authors: 侯文祥
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/k6g7a4

碩士 === 國立臺灣大學 === 生物環境系統工程學研究所 === 106 === This study is based on the case of effectively improving algae bloom occurred in Middle lake of Drunken Moon Lake in National Taiwan University on July 2016. The accurate location is 25°1''12"N 121°32''15"E which located in Da-an District, Taipei City. Putting proper amount of zooplankton-Moina into water with biomanipulation, Euglena was removed from water after 2 days and the transparency also improved. So far, the result of this case is successful because excessive multiplication of Euglena never happened again. According to the above, using zooplankton to reduce phytoplankton (algae) might be a way of biomanipulation. However, the reducing efficiency needs to be verified by experiment and observes the change of water quality after implement biomanipulation. Moina Macrocopa and Chlorella vulgaris are the experimental subjects in this study. In order to provide manual basis data of implementing biomanipulation by zooplankton for small artificial landscape pond, this study builds data for increase and decrease rate between two species. The experiment environment divided into two water temperature, 25°C and 30°C respectively, with Each water temperature has high and low concentration of Moina.spp. Sampling every 3 hours in 24hours and measure reducing efficiency and water quality change. With the experimental design of this study, increase 1 mg Moina.spp could make Chlorella.spp decrease 0.79~1.32 mg and 0.99~1.46 mg at 25°C and 30°C separately. Combined with water quality index, the results show that transparency decline 1 cm, the concentration of Chlorella.spp increase 0.018(g/L), it needs to be reduced by 0.014~0.023(g/L) and 0.013~0.019(g/L) concentration of Moina.spp for water temperate of 25°C and 30°C separately. The Chlorella.spp reduced in shorter time with more quantity of Moina under the same water temperate. What’s more, with same quantity of Moina.spp, Chlorella.spp reduced in shorter time with higher water temperate. This study explicitly builds the experiment methods of measuring zooplankton and phytoplankton consumption efficiency, it could help small artificial landscape pond easier to manage by using biomanipulation.