隨著科技進步與人口增長，廢水排放問題日益嚴峻，污水處理廠面臨成分複雜及處理成本高昂等挑戰。厭氧發酵作為一種有效且環保的廢水處理技術，能夠利用微生物降解有機物，並將其轉化為生質能源甲烷，從而實現資源回收與循環經濟的目標。然而，城市廢水普遍碳氮比(C/N ratio)不適當，且化學需氧量/生化需氧量(COD/BOD)比值較高，導致產甲烷菌活性受抑制，進一步影響甲烷產量。 本研究探討廢水與稻草進行兩階段厭氧發酵的可行性，以提升有機物降解效率並促進廢棄物再利用。作為共發酵基質，稻草可補充廢水中的碳源，從而促進微生物群落的活性。實驗結果顯示，當添加40 g稻草與廢水共發酵時，甲烷產量達348.17 mL，顯著高於單獨廢水發酵(22.76 mL)。然而，當稻草添加量增加至50 g，甲烷產量反而下降至312.68 mL，顯示適量的稻草可作為有效的碳源，過量則可能影響發酵環境，抑制產甲烷作用。 由於稻草主要由難降解之有機物組成，其分解速率較慢，影響微生物的利用效率。因此，本研究進一步評估低溫水熱預處理對稻草共發酵的影響。研究結果顯示，經80°C水熱預處理1小時的稻草，其共發酵甲烷產量顯著提升至592.90 mL，較未處理稻草增加約70%。證明適當的水熱預處理可有效改善底物的降解性，進而提高共發酵效率與甲烷產量。 ;With technological advancement and population growth, wastewater discharge has become an increasingly severe issue. Wastewater treatment plants face challenges such as complex compositions and high treatment costs. Anaerobic digestion is an effective and eco-friendly method that utilizes microorganisms to degrade organic matter and convert it into methane, a bioenergy source, thus supporting resource recovery and the circular economy. However, municipal wastewater has an inappropriate carbon-to-nitrogen (C/N) ratio. and a high chemical oxygen demand to biochemical oxygen demand ratio, which inhibits methanogen activity and reduces methane yield. This study investigates the feasibility of two-stage anaerobic co-digestion of wastewater and rice straw to enhance organic degradation and waste reutilization. As a co-substrate, rice straw supplements the carbon source in wastewater and stimulates microbial activity. Results showed that co-digestion with 40 g of rice straw produced 348.17 mL of methane, more than wastewater alone (22.76 mL). However, increasing the amount to 50 g reduced methane production to 312.68 mL, indicating that excessive rice straw may inhibit methanogenesis. Due to its composition predominantly of resistant organic matter, rice straw exhibits a slow degradation rate, thereby affecting the efficiency of microbial utilization. To address this, low-temperature hydrothermal pretreatment was applied. Rice straw treated at 80°C for 1 hour resulted in a methane yield of 592.90 mL, which is about 70% higher than untreated straw, demonstrating that proper thermal pretreatment can enhance substrate degradability and improve co-digestion performance.
