近年來國內民眾對飲用水的標準日益提升，民眾也相繼在食品及飲用水中發現含有對人體造成危害的化學物質，而臺灣飲用水來源大多都以台灣自來水公司之淨水場配送到各用戶端，而飲用水中含有鋁對人體健康的影響已造成國人的疑慮。因此台灣自來水公司目前正在積極建立飲用水中鋁含量的資訊，並針對各地區的淨水場進行改善，其最直接的改善方式及是更換混凝劑，將原本的鋁系改為鐵系混凝劑。本研究之淨水場因佔地面積不大，淨水場內無混沉程序，故改善方式為使用混沉模組及薄膜系統模組進行淨水場整體效能提升之研究。本研究以台中市東勢區的慶東淨水場為研究對象，研究期間原水均屬於低濁度原水，在此進行未添加混凝劑及添加混凝劑試驗，根據實場操作與模組試驗數據結果推論，實場清水濁度不穩定是因快濾池未能有效達到去除濁度效果，反而有將快濾池中之濾砂從濾床中帶出之疑慮，且無法有效去除水中濁度，導致清水端鋁含量也相對提升，反之模組試驗中得知，經混沉模組及薄膜系統模組後能有效降去除濁度並將水中鋁含量降至標準限值0.2mg/L 之限值內；而添加PACl混凝劑時，水中之殘餘鋁含量主要是由添加混凝劑產生，導致水中殘餘鋁含量提升至標準限值邊緣，故在低濁時可不添加混凝劑，而在中濁度部分，添加適當混凝劑，能使混沉單元有效降低水中濁度，降低過濾單元之負荷，使出水濁讀達標準限值2NTU。 Harmful chemical substances found in food and drinking water has become a growing problem in recent years. The impact of drinking water containing aluminum caused a great concern because of its impact on human health. Government regulations increase the drinking water standards especially in Taiwan. Taiwan Water Corporation is currently active in the improvement of water purification plants for each region and reduction of aluminum content in drinking water.As a result, alternative method was used for the water purification.Instead of using an aluminum based coagulant, iron was used. This study focused on water purification plant covering a small area of non-mixed water purification using the Shen model. The study was done in the water treatment plants of East District, Taichung City. The study was done with low raw water turbidity. The coagulants and coagulant tests were added according to the actual field operations and module test data results were gathered. The actual water turbidity due to high filter capacity is not effectively increase the turbidity results because of the fast filtering the sand quickly move out from the filter bed. Mixing heavy modules and thin-film module system can effectively lower the aluminum content of the water. It is reduced to the standard limit with 0.2mg/L value. Moreover, the residual aluminum content in water is mainly produced by adding coagulant, resulting in residual aluminum content in water to meet the standard limits. Therefore by adding the appropriate coagulant, it can effectively decrease turbidity of the water and reduce the load of the filter unit, the effluent turbidity standard is 2NTU.
