好氧迁移外源有机物转变成内源聚合物驱动内源反硝化

Aerobic Migration of Exogenous Organic Matter Into Endogenous Polymers to Drive Endogenous Denitrification

为解决生活污水碳氮比低、碳源不足导致的生物反硝化脱氮能力差的问题,研究根据活性污泥盛宴/饥饿非稳态理论探索好氧/缺氧(aerobic/anoxic,O/A)工艺模式实现在好氧条件下强化内源有机物积累,用于缺氧条件下内源反硝化脱氮.通过保持O/A时长比为0.11,温度为(28±2)℃,污泥龄(sludge retention time,SRT)为20d的驯化条件,成功实现了进水负荷在0.31~0.41g/(g·d)下好氧迁移56.00%±0.09%的COD,合成(8.05±1.32)mmol/L内源聚合物(聚羟基脂肪酸酯(polyhydroxyalkanoates,PHA)+糖原).缺氧段利用内源积累多聚物反硝化40mg/LNO3--N,内源比反硝化速率为1.53mg/(g·h).以单位NO3--N或NO2--N作为电子受体需要的反硝化内源聚合物的量不同,分别是2.24 mol内源物和1.59 mol内源物.内源反硝化优先消耗PHA,但是糖原贡献了77%的反硝化碳源.16S rRNA高通量测序表明,这种驯化模式显著改变了微生物的种群结构,提高了PHA和糖原积累菌群的丰度.研究结果表明,O/A工艺模式能够强化微生物积累内碳源并提高反硝化脱氮能力.

To solve poor biological nitrogen removal ability because of low ρ(C)/ρ(N)and insufficient carbon source of sewage wastewater,aerobic/anoxic(O/A)process mode enhancing the accumulation of endogenous organic matter under aerobic condition was explored based on the feast/famine non-steady state theory of activated sludge in this paper.Then,endogenous organic matter was used for denitrification in anoxic condition.When the influent load was 0.31-0.41 g/(g·d)and kept the conditions of 0.11 rate of O/A time,temperature(28±2)℃,sludge retention time(SRT)20 d,56.00%±0.09%COD was translated into endogenous polymers and(8.05±1.32)mmol/L endogenous polymers(polyhydroxyalkanoates+glycogen)was successfully accumulated.In the anoxic stage,40 mg/L NO-3-N was removed by endogenous polymers and the endogenous denitrification rate was 1.53 mg/1.53 mg/(g·h).Using NO-3-N or NO-2-N as electron acceptors,the amount of endogenous polymers for denitrifying nitrogen removal was different and were 2.24 mol endogenous source and 1.59 mol endogenous source,respectively.Endogenous denitrification preferentially consumed PHA,but Glycogen contributed 77%of the denitrifying carbon source.16S rRNA high throughput sequencing showed that this domestication mode significantly changed the microbial population structure,promoted the abundance of PHA and Glycogen accumulation microbes.Results show that the O/A process can enhance the accumulation of internal carbon sources and enhance the ability of denitrification nitrogen removal.