单级SBR厌氧/好氧/缺氧处理中期垃圾渗滤液深度脱氮

摘要

The feasibility of using a single sequencing batch reactor to remove nitrogen from medium-age landfill leachate was examined, and an anaerobic/aerobic/anoxic process in a SBR without extra carbon source addition was presented. Dissolved organic matter could be taken up partially and stored as polyhydroxyalkanoates (PHAs) in the anaerobic stage by the microorganisms operated in the anaerobic/aerobic/anoxic process, with glycogen consumption. In the aerobic stage, ammonia was oxidized and accompanied by loss of tatal nitrogen (TN) via simultaneous nitrification and denitrification. The stored PHAs and glycogen, remaining at the end of aerobic stage could provide carbon source for anoxic denitrification. In the stable phase, the effluent COD, NH+4-N, and TN were 525—943 mg·L−1, 1.2—4.2 mg·L−1 and 18.9—38.9 mg·L−1 respectively when the influent COD, NH+4-N, and TN were 6430—9372 mg·L−1, 1025.6—1327 mg·L−1 and 1345.7—1853.9 mg·L−1, respectively. Nitrogen removal from medium-age landfill leachate could be realized via the anaerobic/aerobic/anoxic process in a SBR with the effluent of TN less than 40 mg·L−1. Almost 1/3 of reduced TN was removed via SND, while 2/3 of reduced TN was removed via post-anoxic denitrification.%为了考察单级SBR处理实际中期垃圾渗滤液深度脱氮的可行性，采用单级SBR在“厌氧/好氧/缺氧”（AOA）运行方式下处理实际中期垃圾渗滤液。试验发现，厌氧/好氧/缺氧交替运行下驯化的微生物能在厌氧段消耗胞内糖原，并将水中部分溶解性有机物以聚羟基脂肪酸酯(PHAs)形式储存；在好氧段微生物消耗胞内 PHAs，转化为胞内糖原，氨氧化的同时也伴随着同步硝化反硝化脱氮；好氧段氨氧化结束后贮存的碳源（PHAs 和糖原）能为后置缺氧反硝化提供碳源。经长期试验研究，进水COD、NH+4-N、TN浓度分别为6430～9372 mg·L−1、1025.6～1327 mg·L−1、1345.7～1853.9 mg·L−1，出水COD、NH+4-N、TN浓度能达到525～943 mg·L−1、1.2～4.2 mg·L−1、18.9～38.9 mg·L−1。在未投加外碳源的情况下，SBR法AOA运行方式下能够实现中期垃圾渗滤液的深度脱氮，出水TN<40 mg·L−1。其中，好氧段(DO<1 mg·L−1)通过同步硝化反硝化去除TN占总去除量的1/3左右；缺氧后置反硝化去除的TN占总去除量的2/3左右。