校園人工濕地在啟動期淨化性能與生態觀測解析

THE STUDY OF EFFICIENCY IN CONSTRUCTED WETLAND FOR CAMPUS WASTEWATER TREATMENT IN THE START-UP PHASE

本研究以人工濕地(Constructed wetland, CW)系統來淨化校園污水。建置計畫藉由內政部建築研究所九十二年度「綠色廳舍暨學校改善計畫」之經費，於成功大學建築系設置全國第一座校園人工濕地實場(Full scale on site)，以進行濕地去污性能與生態觀測。本研究濕地建構完成後，全程進行水質監測實驗，水質標準多能符合行政院環保署「放流水標準」。在水質監測部分，BOD5沒有啟動期(the start-up phase)現象，而SS、TP及NH3-N則分別需要5~7週時間。 有機污染物去除效率在BOD5為73.6%、COD為66.6%、SS為73.1%、NH3-N為57.2%、TP為44.4%。在大腸桿菌群方面，景觀水池的去除效率為99.5%、糞便型大腸桿菌為100%；在生態觀測部分，孑孓數量的控制，以放養台灣蓋斑鬥魚比放養大肚魚來得有效，因為大肚魚無法在DO低於1mg/L以下存活。從地球環保觀點而言，以人工濕地來淨化汙水，是省能源、省資源、無二次公害的生態工法。濕地系統的設計參數、操作管理及衍生議題，猶待後續相關研究，以作我國發展永續水資源之參考。

In this research, a constructed wetland system was used for the treatment of the wastewater from campus. This plan was funded by the “Green Remodeling Plan for Governmental Buildings” program of Architecture and Building Research Institute (ABRI). This constructed wetland system is located in Architectural Department of National Cheng-Kung University (NCKU) and is the first full-scale campus constructed wetland established in the nation. The purpose of this research is to implement the observation of the decontamination capability and ecological development in the constructed wetland. After the establishment of this constructed wetland, the observation of water quality was implemented regularly, and the water quality usually meets the requirements of “Discharge Standard” set by Environmental Protection Administration in Taiwan. During the start-up phase of the constructed wetland, the removal efficiencies of constituents from wastewater were 73.6% for BOD5, 66.6% for COD, 73.1% for SS, 57.2% for NH3-N, 44.4% for TP, 57.2% for the colon bacillus, and 57.2% for the fecal coliform. As for the observation of impact factors on the constructed wetland, the established location should expose with sufficient sunlight, and avoid building wind in order to benefit the growth of the macrophytes. Mosquito fish (Gambusia spp.) and Trichogaster trichopterus are cultured in the constructed wetland to control the amount of wiggler. The tolerable condition for Mosquito fish is that NH4-N lower than 77 mg/L and DO higher than 1 mg/L. From the viewpoint of global environmental protection, treating wastewater by constructed wetland is an ecological method which can achieve energy conserving, resource saving, and without further public pollution. As for the design parameters, management and maintenance measures, and other related issues of constructed wetland need to be investigated in the future.