以水準流式生物濾床串連地下流式人工溼地處理養豬廢水之可行性評估

The Assessment of Swine Wastewater Treatment by Horizontal Biofilter Combined with Subsurface Constructed Wetland

謝効余(Hsiao-Yu Hsieh) ； 郭文健(Wen-Chien Kuo) ； 楊磊(Lei Yang)

《濕地學刊》 1卷2期 (2012/07) Pp. 1-10

https://doi.org/10.30124/JW.201207.0001

摘要

台灣地區的河川三大污染源，分別為工業廢水、畜牧廢水及生活汙水，其中的畜牧廢水因為富含氮、磷營養鹽，同時也伴隨著溶氧量過低，懸浮固體含量過高等特性，因此造成處理上的困難。目前國內的養豬廢水處理系統為三段式處理系統為主，即經固液分離、厭氧消化、活性污泥系統。雖然能夠有效的將廢水的化學需氧量及懸浮固體降低至行政院環保署之排放標準（即生化需氧量80mg/L、化學需氧量600mg/L、懸浮固體150mg/L）以下，但排放水中的氮、磷營養鹽無法經過濾、沉澱等方式去除。另一方面，傳統的三段式處理系統中的第三段活性污泥系統，操作不易且曝氣槽所需之電力消耗高，使得一般養豬戶無法妥善的管理經營。若是將廢水排放進入一般自然水體，或是自然溼地水體中，將造成水體優養化等環境問題。本研究係利用水平流式生物濾床（Horizontal Biofilter, HBF）串連地下流式人工溼地（Subsurface SystemConstructed Wetland, SFSCW），取代舊有傳統的三段式處理系統中的第三段活性污泥系統，進行養豬廢水處理之可行性評估。水平流式生物濾床是以固定膜生長的方式取代原有活性污泥系統的懸浮生長，操作簡單且不需進行污泥迴流操作。透過生物膜的生長達到轉換有機物，達到去除之目的。經HBF處理後之排放水，再經由SFSCW進一步處理，而該礫石床上種植之美人蕉（＂Canna indica＂）以及礫石間隙生成之生物膜亦可去除部分過多的營養鹽。本串聯處理系統自2010年12月至2011年3月操作四個月，以HBF之水力停留時間約30小時測試，已有相當不錯的成效。在懸浮固體與化學需氧量之去除率，分別達到80.91%與68.15%。其中HBF與SFSCW系統分別提供了約七到八成以及一到二成的去除率。此設計之自然處理系統最終排放水皆可達到法定標準之下，在細節設計上若能夠稍做修正，如加裝逆洗裝置等，並且在後續測試多種水力停留時間以及汙染負荷係數，應可推廣至各養豬用戶，以改善現今傳統三段式廢水處理系統。

關鍵字

水準流式生物濾床 ； 地下流式人工濕地 ； 養豬廢水 ； 美人蕉

並列摘要

Swine wastewater is one of the major pollutions in Taiwan. The abundant nutrition and organic matters in it may lead eutrophication of water body. Meanwhile, the low dissolved oxygen level and high suspended solids concentration may also make it more difficult to handle the wastewater treatment. At present facility of swine wastewater in Taiwan is the three-process treatment which includes the solid-liquid separation, anaerobic digestion, and activated sludge system. Even though the three-process treatment is widely used, the efficiency of sediment and filter effectively to remove the nutrition, e.g., ammonia and phosphate is still in question. On the other hand, the activated sludge system is a difficult technique that the swine farmers can’t easily to operate. Based on these reasons, an efficient swine wastewater treatment process should be established. In this study, we replace the activated sludge system in three-process treatment with the horizontal biofilter (HBF) and subsurface system constructed wetland (SFSCW) to assess the practicability of improving the traditional process. HBF is a fix-biofilm system which is superior to the suspended growth of activated sludge system by its simple operation and no need to return the sludge from the final clarifier. Porosity in the gravel of SFSCW and the root zone of Canna indica can also help to remove the nutrients from the outflow of HBF. The tested HRT (hydraulic retention time) has been controlled at about 30 hours and results show that SS and COD removal efficiencies as 80.91% and 68.15%, respectively. HBF and SFSCW provided approximate 70~80% and 10~20% removal efficiencies, respectively. This design of combining HBF and SFSCW system has high potential to treat the swine wastewater, and adding the backwash unit may further facilitate the operation in the future.

並列關鍵字

Horizontal Biofilter (HBF) ； Subsurface Flow System Constructed Wetland (SFSCW) ； Swine Wastewater ； Canna indica