由於國內對於應用人工溼地淨化醫療社區污水廠二級放流水淨化資料的闕如,因此本計
畫擬於嘉義縣大林慈濟醫院園區設置人工溼地實驗系統,以有系統的方式處理該醫療園區污水
廠之二級放流水,使污水廠所排放之二級放流水能夠進一步淨化,並增加放流水的再利用性與
再利用的範圍。大林慈濟醫療園區除了醫療設施之外,尚有許多一般居住及教學的設施,因此
醫療廢水僅佔污水量的一部份。根據慈濟大林醫院園區過去水質分析記錄,顯示該污水廠的處
理效果良好,均符合「放流水標準」,但是硝酸鹽的卻始終很高,因而限制了再利用作為澆灌
用水的目的。本計畫以人工溼地實驗實場作為三級處理設施,配置以自由表面流(free water
surface system, FWS)人工溼地,以及表面下流動(subsurface flow system, SSF)人工溼地進行處
理,並且在人工溼地系統之後設置一生態池,除了可增加景觀、生態等多樣性功能,並且還可
用來持續觀察處理過後的水質。
研究結果顯示,本研究之人工濕地在污水進流量100CMD 的操作下,總氮濃度可由進流
為37.1±7.7 mg N/L,在FWS 溼地出流時降低為23.2±7.2 mg N/L,在SSF 溼地出流時進一步降
低為23.2±7.2 mg N/L,去除效率約為64%,總磷由進流的5.5±1.4 mg P/L,至FWS 溼地出流
時降低為4.6±1.2 mg P/L,SSF 溼地出流更進一步降低為3.7±1.3 mg P/L,去除效率為33%。進
一步比較本研究人工濕地其他操作試程的氮、磷去除速率(啟動期與穩定操作期1),本研究試
程(100 CMD 高硫量試程)的氮磷去除表現均比其他兩個試程優越,顯示濕地在穩定操作且良好
的維護管理下,生態結構越趨健全,藉由植物所貢獻的碳源,可促進濕地脫銷作用的進行,並
且在的採收管理下,可促使植物攝取水中的磷。另外,本研究人工濕地處理過後的淨化水,渴
再利用於植栽的澆灌、景觀、道路沖洗等用途。 The information of using constructed wetlands for polishing medical treatment discharge is
scarce in Taiwan. This proposal plans to use the constructed wetland systems built in Tzu-Chi Dalin
Hospital area to treat the discharge from its wastewater treatment plant systematically so as to
improve the water quality for further reuse. The wastewater from Tzu-Chi Dalin Hospital area
includes hospital and municipal wastewater. According to the water quality records of Tzu-Chi Dalin
Hospital, the discharge of its wastewater treatment matches “Discharge Standards” of EPA. However,
the nitrate concentration is remained high in the discharge, so that limited for reclaiming as irrigation
purpose. In this plan, the constructed wetland system is used as a tertiary treatment system. A free
water surface wetland (FWS) followed by a subsurface flow wetland (SSF) are planned to proceed
the experiment. A scenic pond is built at the end of the wetland system for observing the water
quality in a natural environment and also providing aesthetic and ecological functions.
As results, the study wetland treated the discharge from its wastewater treatment plant about
3
100CMD. Influent total nitrogen (TN) was 37.1±7.7 mg N/L, and it composed of 97 % nitrate and
3% other nitrogen compounds (TKN, ammonia, and nitrite). So the study wetland treated main
contamination was nitrate. A FWS wetland reduced TN from 37.1±7.7 mg N/L to 23.2±7.2 mg N/L
and SSF wetland reduced to 23.2±7.2 mg N/L. TN removal efficiency was about 64%. The nitrogen
removal in the study constructed wetland was dependent on denitrification. Influent total phosphorus
(TP) was 5.5±1.4 mg P/L. A FWS wetland reduced TP from 5.5±1.4 mg P/L to 4.6±1.2 mg P/L, and
a SSF reduced TP to 3.7±1.3 mg P/L. TP removal efficiency was about 33 %. Compare with star up
phase and stable operating phase 1, this study phase (flow rate was 100CMD) showed that high
nitrate and TP removal rate than other phases. Because of the study wetland stably operated and
maintain well, promoted to more integration ecological. Residues of plant can contribute carbon
source promote denitrification, and growing plant can uptake phosphorus. Treated water in this study
can use to plant irrigation, landscape, road wash.