| 摘要: | 有鑑於世界各國相繼訂定飲用水中鋁含量標準或建議值，雖然目前臺灣飲用水水質標準目前未訂定飲用水中「鋁」含量之限值，但行政院環保署日前亦已將其列入飲用水水質即將列管的標的之ㄧ。台灣的淨水場大多是以聚氯化鋁(PACl)與硫酸鋁(Alum)為主要混凝劑。根據研究結果發現大部分淨水場於清水中的總鋁濃度有超出0.2 mg/L的情況。面對未來的水質標準，本研究即針對水上淨水場 (五區)，潭頂淨水場 (六區)，研擬降低淨水場內清水含鋁量之改善對策。首先於潭頂淨水場內，採用低濁11.70 NTU之原水、鹼度162 mg/l、pH 8.0，此時硫酸鋁混凝劑添加劑量為5 mg/L 可有效降低濁度至 5 NTU以下。分析總鋁型態，發現其顆粒鋁與溶解鋁皆超出標準，若依殘餘鋁濃度推判，其原因皆為混凝劑過量加藥。在不改變混凝劑種類的操作限制下，混凝劑量以殘餘鋁控制劑量為主，可放寬沉澱出流水濁度，但須控制過濾池出流水的濁度皆能維持在0.2 NTU以下。改變混凝劑種類以氯化鐵為主混凝劑，可以降低水中殘餘鋁濃度。研究結果顯示單純氯化鐵使用，最高殘餘溶解鋁量約僅單獨硫酸鋁之一半。於水上淨水場內，採用低濁14.6 NTU之原水、鹼度230 mg/l、pH 8.0，此時聚氯化鋁混凝劑添加量為 5 mg/L 可有效降低濁度至 2 NTU以下。分析總鋁型態，發現其顆粒鋁與溶解鋁皆超出標準，若依殘餘鋁濃度推判，其原因為原水即含有大量溶解鋁，此溶解鋁並無法於淨水單元中被去除。改變混凝劑種類，以氯化鐵為主混凝劑，可以降低水中殘餘鋁濃度。研究結果顯示單純氯化鐵使用，水中殘餘溶解鋁可控制在0.03 ~ 0.06 mg/L。
View of the world have set drinking water standards or recommendations of aluminum content in value, "aluminum" content in drinking water limit Taiwan drinking water quality standards are not set, but the EPA has also columninto the quality of drinking water coming out the tube is the subject of Taiwan. Most of the water purification plant in Taiwan the polyaluminum chloride (PACL) as the main coagulant aluminum sulfate (Alum).According to the results exceed 0.2 mg /L in most of the water purification plant in the total aluminum concentration in the water. Future water quality standards, the study for the Shui-Shang water treatment plant (five districts), Tan-Ding water treatment plant (six districts), develop improvement measures to reduce the water content of aluminum in water purification venue.First of all in Tan-Ding water treatment plant, the raw water with low turbidity of 11.70 NTU, alkalinity 162 mg / l, pH 8.0, the amount of aluminum sulfate coagulant additives to 5 mg / L can effectively reduce turbidity to 5 NTU. Analysis of total aluminum patterns and found that the aluminum particles and dissolved aluminum are beyond the standard, Zoe concentration of residual aluminum push-contracting, its causes are excessive coagulant dosing. Does not change the the coagulant type of operation restrictions, the of coagulant amount of residual aluminum control dose-based, can be relaxed to precipitate the water turbidity, subject to control and filter pool water turbidity encountered maintained at 0.2 NTU or less. Change the the coagulant type of ferric chloride-based coagulants can reduce the concentration of residual Al. The results showed that pure ferric chloride, the only single aluminum sulfate of the maximum residue dissolved aluminum is about half.At the Shui-Shang water treatment plant, low turbidity 14.6 NTU's raw water alkalinity 230 mg / l, pH 8.0, poly aluminum chloride coagulant dosage is 5 mg / L can effectively reduce the turbidity of 2 NTU or less.Analysis of total aluminum patterns and found that the aluminum particles and dissolved aluminum are beyond the standard, If things had gone according to the concentration of residual aluminum push-contracting, the reason for the raw water contains a lot of dissolved aluminum, dissolved aluminum and can not be removed in a water purification unit.Change the type of coagulant, ferric chloride-based coagulant, and can reduce the concentration of residual Al.The research results show that the pure ferric chloride, the residue was dissolved in water to aluminum can be controlled at 0.03 to 0.06 mg / L. |
