回收淨水場廢水對淨水處理影響及最適化控制之研究

The Effect and Optimum Control of Reusing Wastewater to Water Treatment Plants

盧怡均(I-Chuan Lu)

指導教授 ： 張添晉

國立臺北科技大學/工程學院/環境工程與管理研究所/碩士(2010年)

摘要

基於台灣水資源短缺及因應資源再利用之國際環保趨勢，回收廢水並再利用更顯其重要性，台灣自來水公司迴用淨水場廢水已行之有年，但迴用廢水後污染物重複累積而增加淨水負荷或提高飲用風險之疑慮，卻為鮮少探討之議題。
本研究挑選6座具有代表性之淨水場，針對各淨水場豐、枯水期之廢水水質進行檢驗，結果顯示大部分淨水場回收廢水皆可符合自來水公司內控標準，少部分回收水源如坪頂淨水場廢水池上澄液之懸浮固體含量超過內控標準；而藻類及原蟲等項目雖未列管於內控標準中，但亦有鯉魚潭淨水場豐水期廢水池上澄液及污泥濃縮池上澄液具有藻類之迴用疑慮，而迴用另有梨型鞭毛蟲及隱孢子蟲問題之回收水源則為坪頂淨水場枯水期污泥濃縮池上澄液及麥寮第二淨水場豐水期廢水池上澄液。
本研究以水質分析結果作為板新及龍潭淨水場之實場驗證依據，分別研擬提昇廢水水質及減少22-37.3 %廢水量之建議。最後結合水質分析及實場驗證結果為參考，規劃淨水場回收廢水之最適化控制，以懸浮固體作為指標，淨水場廢水迴流率100%之情況下，對於迴用後水源中懸浮固體影響比例介於1.11-77.33 %，本研究設定廢水迴流後可接受之影響比例應低於10 %，則6座淨水場上澄液迴流率範圍應控制於4.8-100 %；此外，除了控制迴流量以降低對淨水程序之衝擊外，並可以濁度作為現場操作指標及相關水量指標之計算，加以提升廢水迴用之安全性。

關鍵字

淨水場 ； 廢水回收 ； 最適化控制 ； 懸浮固體

並列摘要

Due to lack of water resource in Taiwan as well as trend of global resource utilization, wastewater recycle and reuse is truly important. For Taiwan Water Corporation, reusing wastewater out of water purification process has been implemented for several years. However, the pollutants of reusing wastewater were cumulative, which resulted in the pollution loading of water treatment process and the risk of drinking water quality. But the topics were rarely discussed.
This study selected 6 representative water treatment plants, focusing on their wastewater qualities in different seasons. The result shows that most of the plants were qualified with the internal control standards. Only the supernatant in Pingding Water Treatment Plant exceeded the concentration of suspended solids for internal control standard. Although algaes, Giardia lamblia and Cryptosporidium parvum did not list in the internal control standards, the supernatant from wastewater basin and sludge thickener in Liyutan Water Treatment Plant still had some doubts about algaes reuse during wet season. Besides, the supernatant from sludge thickener in Pingding Water Treatment Plant and wastewater basin in Mailiao Water Treatment Plant had some problem related to the recycling water contained Giardia lamblia and Cryptosporidium parvum during wet season.
The study established the wastewater background information as the foundation of on-site diagnose for Bansin water treatment plant and Longtan water treatment plant. The study utilized the results of water quality analysis to draft the operational recommendations to enhance the quality of wastewater and reduce the quantity of wastewater about 22-37.3%, respectively.
Finally, integrating the results from water quality analysis and the on-site evaluation, this study planned recycling wastewater in the water treatment plant including the operation procedure of suspended solids as an indicator of pollutants. Assumption the condition of supernatant recycle ratio was 100%，the effect ratio of suspended solids in water source were between 1.11-77.33%. The study provided the effect ratio of suspended solids in water source should be lower than 10%, and the 6 water treatment plants must control the recycle ratio between 4.8-100 %. In addition to control the supernatant recycle ratio to reduce the impact of water treatment process, turbidity as an operational indicators of on-site and relative quantity of water indicators to enhance the security of reusing wastewater.

並列關鍵字

Water treatment plant ； wastewater recycling ； optimum control ； suspended solids

參考文獻

【64】 行政院環境保護署，http://www.epa.gov.tw/

【5】 甘其銓、萬孟瑋、邱郁婷、林敬涵、蔡一如、李孫榮，「截流式微過濾搭配混沉處理回收淨水場濾池反沖洗水之研究」，嘉南學報，33期，2007，pp.167-178。

【7】 姜佳伶，淨水場沉澱及過濾單元濁度去除及其衍生廢污量之研究，碩士，國立中央大學，桃園，2007。

【11】 United States Environmental Protection Agency, ” Safe Drinking Water Act Amendments”, 1996.

【12】 United States Environmental Protection Agency, ”Filter Backwash Recycle Rule”, 2001.