低碳氮比和高pH进水启动短程反硝化:性能及污泥特性变化

Performance and Sludge Characteristic Changes in Process of Low Carbon Nitrogen Ratio and High pH to Start Short-range Denitrification

短程反硝化厌氧氨氧化技术(PDA)在污水处理中广泛应用的前提是富集出足量的短程反硝化细菌。通过接种剩余污泥,考察了采用简单的调控进水pH和碳氮比(C/N)策略,在上升流式厌氧污泥床(UASB)反应器内进行长达77 d短程反硝化启动过程。结果表明:在反应器的进水C/N(~2.6)与pH(~9)条件下,出水快速出现了亚硝态氮积累,在40 d以后,反应器内的亚硝积累率(NTR)保持稳定,NTR为(54.67±7.29)%,表明了短程反硝化过程已经在反应器内建立。此外,将进水pH调节为7.5,NTR依然稳定在(66.13±0.77)%,驯化后的污泥适用于常规污水的PD过程。高pH条件下反应器内污泥浓度上升,微生物对进水的适应导致了胞外聚合物(EPS)下降,EPS中的蛋白和多糖比例的变化反映了污泥具有颗粒化的趋势。结果表明:控制进水高pH和低C/N比成功启动了短程反硝化过程,驯化后的污泥可以用于PDA脱氮,尤其在同时处理含有氨氮和硝态氮废水时具有显著优势。

The widespread application of short-range denitrification anammox technology in wastewater treatment is based on the enrichment of sufficient short-range denitrification bacteria.By inoculating residual sludge,the short-range denitrification starting process for 77 d long in the upflow anaerobic sludge blanket(UASB)reactor based on the strategy of simply regulating and controlling the pH and carbon to nitrogen ratio(C/N)of the influent is studied.The results show that nitrite nitrogen is rapidly accumulated in the effluent under the condition of the influent C/N(~2.6)and pH(~9)in the reactor.After 40 d,the nitrite accumulation rate(NTR)remains stable in the reactor,and NTR is(54.67±7.29)%,which indicates that the short-range denitrification process has been established in the reactor.In addition,the NTR is still stable at(66.13±0.77)%by adjusting the pH of influent to 7.5.And the domesticated sludge is suitable for the PD process of conventional wastewater.The concentration of sludge in the reactor will increase under the condition of high pH.The adaptation of microorganisms to the influent will lead to a decrease of extracellular polymeric substances(EPS).The changes in the ratio of proteins and polysaccharides in EPS reflect the trend of sludge granulation.The results show that regulating the high pH and low C/N ratio in the influent can successfully start up the short-range denitrification process.The domesticated sludge can be used for nitrogen removal of PDA,especially in the simultaneous treatment of wastewater containing ammonia and nitrate,which has significant advantages.