校區廢汙水之物質流研究－以臺大為案例

Abstract

水資源相關課題於我國臺灣地區，一直以來是為眾人關切的焦點，在衛生工程領域下水道系統之規劃設計，特別是在廢汙水量推估方面，往往僅依循一般經驗公式產出；物質流分析以系統化的研究架構可輔助既有研究工具的準確性與整體觀，幫助吾人於探討水資源的質量平衡，進一步深入檢視、瞭解廢汙水的流轉概況。 國立臺灣大學除了在推動「永續校園」有良好初步成果展現，另外值此「邁向頂尖大學」之際，更加著重於校區內汙水下水道系統等硬體環境基礎建設工程。本研究以其為案例，藉由實際調查與資料搜集等，透過物質流分析方法探討校園廢汙水之流布。 研究結果顯示，「汙一區」用水成長趨勢逐年減緩，2004年耗水量共1,694,187 m3，廢汙水總量為1,483,371 m3，兩者比值為0.86，平均日廢汙水總量推估為4,052.93 CMD。倘將分區以內的廢汙水量相關類別予以合併，並以比例表示之；實驗廢水的比例約佔分區以內廢汙水總量之38.5 %，館舍生活汙水的比例約佔24 %，宿舍生活汙水的比例約佔20.7 %，漏水的比例約佔6.7 %，泳池與體育館排水的比例約佔6.3 %，餐廳廢水的比例約佔3.8 %。 由本研究結果與歷來校區汙水下水道系統規劃報告相較，倘若採以用水量360 Lpcd或300 Lpcd來推估計畫目標年廢汙水量，可能會造成投資浪費。建議以物質流研究建立後續更為完善的基線資料，並且建構指標型系統應用，可茲據以評估校園水資源概況，提供予決策者規劃或管理上之參考依據。

In order to investigate water resources, experience equations are usually used, especially in the presumption of the flow rate, in planning and designing the sewerage system. Material Flow Analysis (MFA) is one of the useful methods for us to evaluate flowing conditions of fluids and to analyze the mass balance between water and wastewater in a systematic way. National Taiwan University (NTU) plans to build several basic environmental constructions like the sewerage system. This research takes the sewerage system in NTU as a case with using MFA method and real data to explore the flow conditions of the wastewater in the campus. The result showed that the consuming rate of water, in section one, goes down and down in recent years. In 2004, there is totally about 1,694,187 m3 water used and about 1,483,371 m3 wastewater emitted. The ratio water used/wastewater emitted is 0.86. The total quantity of the wastewater is 4,052.93 CMD. By classifying the sources of the wastewater in district, we can get the ratio of 38.5 % from the experimental wastewater, 24 % from buildings, 20.7 % from dorms, 6.7 % from leakage, 6.3 % from swimming pool and the gymnasium, and 3.8 % from restaurants. It may cause money-wasting for the resources if we use 360 Lpcd or 300 Lpcd as the designing wastewater flow rate. Therefore, this research suggests that using MFA method as a tool to evaluate the baseline data for further plans, and build the index to assess the water resource conditions in campus, and then serving as a basis for the managers to plan or manage.