| 摘要: | 本研究計劃為延續第一年度的工作,在溼地系統的建立後並達到穩定操作狀況下,對二仁溪水質持續的監測以及污染河水的處理成效探討。本年度的重點在於此人工溼地在處理污染河水之效能,受河水水質因隨季節變化的影響。由於冬季時二仁溪溼地系統中之水生植物多已休眠或死亡,所以在此期間的主要工作在於重新種植水生植物,使得本報告討論範圍內(87年8月至88年7月)缺少88年1與2月的資料。對於二仁溪水(亦即溼地系統之進流水)的主要監測項目為一般營養鹽、懸浮固體及物理性質。二仁溪進流水中的COD在春季期間大約在100 mg/L上下有時高至360 mg/L,夏季計時則降低至70 mg/L左右。氨氮則維持在3至19 mg/L之間。磷酸鹽的濃度主要介於2至8 mg/L之間,流量大時則明顯的下降。TSS的分布則十分廣,由數mg/L至三百多mg/L。尤其是颱風期間,由於上游的沖刷,TSS可上升至1,000 mg/L以上。至於物理性物質,pH值維持在7至8之間。溶氧則介於0.2至8.0 mg/L之間。鹽度從十一月開始增加,最高可達2.3%,五月開始因河水流量的增加,鹽度則逐漸降為0。水溫介於攝氏21至34度之間,平均為27.6度左右。整年度的平均去除效率:COD為22.6%、氨氮為60.7%、正磷酸鹽為46.1%與總懸浮固體為70.9%。相較對照組之17.3%、35.5%、19.2%與60.7%,種植水生植物的人工溼地系統具有較佳的淨化水質的功能。因為季節變化導致河水發生春秋翻騰現象以及枯水期時水中因海水漲潮導致的鹽度增加為影響此溼地生態最主要的因素。就淨化水質而言,選擇能適應此類環境變化之植物種類為首要工作。目前已選種一適合的水生植物,如果能持續一年以上,則可以繼續探討相關生態之變化與淨化水質有關的操作參數。
The work of this year, an extending research from last year, is using a completely built constructed wetland (CW) system, which had been stably operated to persistently monitor the water quality of Er-Ren River and study the treating effect of polluted river water. The main goal of this year's work focused on the effects of river water quality followed the seasonal changes and further understood the influence on the efficiencies of polluted water treatment by the CW system. During this research work (August 1998 to July 1999), most of the macrophytes were stopping growing or even died off during the winter. Hence, experimental data were missed for January and February 1998 due to replanting work. The monitored constituents in the water samples are general nutrients (COD, ammonia-N, orthophosphate, etc.) suspended solids, and some physical properties. In the influent from Erh-Ren River, COD concentration was ranged from 100 to 360 mg/L during spring and dropped to about 70 mg/L during summer. Ammonium concentration was maintained between 3 and 19 mg/L. Orthophosphate concentration was ranged from 2 to 8 mg/L and the concentration was dropped significantly when the flow rate increased in the summer. Suspended solids were changed from several mg/L to more than three hundred mg/L. During typhoon days, TSS could raise up to 1,000 mg/L due to the eroded soil from upstream. The physical properties: pH was ranged from 7 to 8; DO was ranged from 0.2 to 8.0 mg/L. The salinity started to increase from November and the highest level was about 2.3%. From May, the salinity gradually decreased to 0% when the flow rate of river increased in summer. Water temperature was ranged from 21 to 34.degree.C with an average of 27.6 .degree.C. The average removal efficiencies during the whole year operation are: COD 22.6%, ammonia-N 60.7%, orthophosphate 46.1% and total suspended solids 70.9% and the efficiencies of the control system are 17.3%, 35.5%, 19.2%, and 60.7%, respectively. The results of these two systems indicate that the CW system planted with macrophytes has the better ability in purifying polluted river water. Thermal stratification effect and increasing salinity in influent in low river flow rate period are the main factors affecting the wetland ecology. For water purification, selecting the species of macrophytes which can tolerate such environment is the most important work. To date, a species of reed had been found growing well through the environmental change. If it can maintain such growing condition for over a year period, then further investigation work about operational strategies and relative ecological change will be continued |
