一体式PN/A工艺处理污泥热水解厌氧消化液性能研究及微生物解析

The performance and microbial community analysis of an one-stage PN/A process for treating anaerobic digestion effluent after thermal hydrolysis

污泥热水解厌氧消化液是一种典型的高氨氮、高COD且含有抑制性难降解有机物的废水.本研究采用一体式部分亚硝化-厌氧氨氧化(PN/A)工艺处理污泥热水解厌氧消化液,通过曝气模式优化调控实现了脱氮性能提升,并研究了长期稳定运行的可行性.结果表明,污泥热水解厌氧消化液对氨氧化菌(AOB)与厌氧氨氧化菌(AnAOB)活性均有抑制,且对AnAOB抑制更明显.调整间歇曝气模式且控制DO<0.5mg·L^(-1),可实现80.6%±3.1%总氮去除率,总氮负荷达到(0.069±0.028)kg·m^(-3)·d^(-1),但长期稳定运行有待优化.AOB的优势菌属为Nitrosomonas属,其相对丰度因污泥热水解厌氧消化液的引入先降低,后随曝气模式调整适应后恢复;AnAOB的优势菌属为Ca.Brocadia,其相对丰度随热水解消化液的持续引入而持续降低,对长期稳定运行提出挑战;反硝化菌(DNB)的优势菌属为Thauera,其相对丰度略升高,反硝化脱氮贡献增强.KEGG功能预测表明膜转运及信号传导通路丰度持续降低,影响群落菌属间膜运输途径的物质信息交流,可能是污泥热水解厌氧消化液抑制作用发生的机制.

Sludge dewatering liquor from thermal hydrolysis pretreatment coupled anaerobic digestion(THP-AD)is a typical high-strength wastewater containing high ammonia and recalcitrant organic compounds.This study focused on the treatment of THP-AD dewatering liquor using one-stage partial-nitritation and anammox process(PN/A)within an activated sludge system.The enhancement of nitrogen removal was obtained through the optimization of aeration patterns,and stable long-term operation was investigated.The findings revealed that THP-AD dewatering liquor exhibited inhibitory effects on ammonia oxidation bacteria(AOB)and a more ponounced impact on anaerobic ammonia oxidation(Anammox)bacteria.Total nitrogen removal efficiency(NRE)of 80.6%±3.1%and TN removal rate(TNRR)of(0.069±0.028)kg·m^(-3)·d^(-1) were achieved under an intermittent aeration mode at dissolved oxygen(DO)concentration below 0.5 mg·L^(-1).However,the study identified the imperative improvement for its long-term stable operation.The dominant genus of AOB,Nitrosomonas,experienced a decline upon the introduction of THP-AD dewatering liquor,followed by recovery after the change of the aeration pattern.Conversely,the relative abundance of Ca.Brocadia,the predominant genus of anammox bacteria,exhibited a consistent decrease over the operational period,posing a challenge to long-term stability.The dominant genus of denitrifying bacteria(DNB)is Thauera,with a slightly increased abundance,enhancing the denitrification contribution for nitrogen removal.KEGG functional predictions indicated a continuous decrease in the abundance of membrane transport and signal transduction pathways,affecting the inter-genus membrane transport information exchange within the community.This may be a mechanism underlying the inhibitory effects of THP-AD dewatering liquor.