PN/A双菌层系统的构建及其脱氮性能

分别采用SBR反应器和MBR反应器驯化培养亚硝化污泥和厌氧氨氧化(anaerobic ammonia oxidation,ANAMMOX)污泥,并通过微生物包埋技术将两类污泥分别包埋,构建亚硝化-厌氧氨氧化(partial nitrification-ANAMMOX,PN/A)双菌层系统.短期实验证明该系统中亚硝化菌(ammonia oxidizing bacteria,AOB)和ANAMMOX菌在不同阶段分别起主导作用,维持系统的酸碱平衡,并实现NH+4-N的高效去除(98.8%).长期实验表明,在溶解氧受限时,PN/A双菌层系统能够有效提高系统对溶解氧的利用效率,并增强系统的稳定性和脱氮效能.在溶解氧为1.0 mg·L~(-1),进水NH+4-N质量浓度分别为200 mg·L~(-1)和400 mg·L~(-1)时,对照组脱氮效率仅为58.1%和61.4%,而PN/A双菌层系统脱氮效率均稳定在80%左右;溶解氧为3.0mg·L~(-1),进水NH+4-N质量浓度为400 mg·L~(-1)时,PN/A双菌层系统总氮去除率达87.9%,总氮积累负荷(NLR)为0.4kg·(m3·d)-1,总氮去除负荷(NRR)为12.8 mg·(g·h)-1.

Nitrogen Removal of Double-bacteria-layer System via PN/A Process

Nitrification and anaerobic ammonia oxidation (ANAMMOX) sludge was acclimated via SBR and MBR reactors respectively, both of which were embedded with microbial immobilization technology and spliced together to construct a PN/A double-bacteria-layer system. A short-term experiment proved that ammonia-oxidizing bacteria (AOB) and ANAMMOX bacteria in the system played dominant roles separately in different stages, which maintained the acid-base balance and achieved efficient removal of NH₄⁺-N (98.8%). A long-term experiment showed that the PN/A double-bacteria-layer system improved the utilization of dissolved oxygen (DO) and enhanced the stability and nitrogen removal efficiency, with limited dissolved oxygen. The nitrogen removal efficiency of the PN/A double-bacteria-layer system remained stable at~80% when the influent NH₄⁺-N was 200 mg·L^-1 or 400 mg·L^-1 in the presence of 1.0 mg·L^-1 DO, whereas those of the control group were only 58.1% and 61.4%, respectively. When influent NH₄⁺-N and DO were 400 mg·L^-1 and 3.0 mg·L^-1, respectively, the PN/A double-bacteria-layer system achieved a nitrogen removal efficiency, nitrogen loading rate (NLR), and nitrogen removal rate (NRR) of 87.9%, 0.4 kg·(m³·d)^-1, and 12.8 mg·(g·h)^-1, respectively.