光照與運作模式對藻菌顆粒污泥系統污染物去除效能之影響

Abstract

藻菌顆粒污泥結合藻類與好氧顆粒污泥的優勢，不僅具備顆粒污泥的快速沉降特性，亦能有效的同步去除有機物、氮與磷。然而，該系統仰賴適當的光照以維持藻類活性及藻菌共生關係。若以自然光為光源，夜間缺乏光照可能抑制藻類對氮磷的去除功能；反之，若採用人工光源進行24小時連續照明，雖可持續提供光照，卻可能促使絲狀藻類過度生長，導致污泥沉降性劣化，並影響出流水水質。為探討光照條件與運作模式對系統處理效能與微生物組成之影響，本研究設置三組序批次反應槽：(1) A槽：24小時連續光照並持續運作；(2) B槽：12小時光照且日夜皆持續運作；(3) C槽：12小時光照，夜間則進入閒置。 研究結果顯示，長光照有助於顆粒粒徑增大並提升總氮去除效率，然而絲狀藻類過度生長導致沉降性惡化；相對的，短光照條件則有助於維持良好的沉降性能。在光暗週期的比較中，光照期的總氮去除率優於黑暗期，顯示光合作用對系統具顯著正面效益。微生物群落分析亦顯示，不同運作模式產生菌群與微藻的組成差異，進而影響系統整體表現。綜合各項指標，採用12小時光照並於夜間閒置之C槽在有機物與營養鹽去除效率及污泥沉降性方面表現最佳，SCOD去除率達97.4%、總氮去除率為84.5%、總磷去除率為71.4%、SVI30為56.5 mL/g，為效能最佳之運作模式。

Algal-bacterial granular sludge (ABGS) integrates the advantages of both algae and aerobic granular sludge, exhibiting rapid settling properties and the capability to simultaneously remove organic matter, nitrogen, and phosphorus. However, this system relies on appropriate illumination to maintain algal activity and the symbiotic relationship between algae and bacteria. Natural light sources may inhibit algal nitrogen and phosphorus removal functions during nighttime, while continuous artificial illumination can promote excessive filamentous algae growth, deteriorating sludge settling properties and affecting effluent quality. To investigate the effects of illumination conditions and operational modes on system performance and microbial composition, this study established three sequencing batch reactors (SBR): (1) Reactor A: continuous 24-hour illumination with continuous operation; (2) Reactor B: 12-hour illumination with continuous operation; (3) Reactor C: 12-hour illumination with nighttime idle periods. Results demonstrated that extended illumination facilitated granule enlargement and enhanced total nitrogen removal efficiency; however, excessive filamentous algae growth deteriorated settling properties. Shorter illumination conditions maintained good settling performance. Total nitrogen removal during illumination periods was superior to dark periods, indicating photosynthesis benefits. Microbial community analysis revealed that different operational modes resulted in variations in bacterial and microalgal compositions, affecting overall system performance. Reactor C demonstrated optimal performance in organic matter and nutrient removal efficiency as well as settling properties, achieving SCOD removal of 97.4%, total nitrogen removal of 84.5%, total phosphorus removal of 71.4%, and SVI30 of 56.5 mL/g, representing the most effective operational mode.