不同运行参数操控下AAO工艺脱氮除磷效果优化研究

Optimization of Nitrogen and Phosphorus Removal Effect of AAO Process under Different Operation Parameters

传统AAO工艺存在SRT矛盾、碳源竞争和回流比冲突等问题,这是制约工艺处理效果的重要原因。为提高AAO工艺的脱氮除磷效果,该研究设计了一种一体化反应器装置,分析了不同回流比、反应区体积比和两点进水比对工艺脱氮除磷效果的影响。结果表明:改变回流比和反应区体积对COD和NH_(4)^(+)-N的去除率影响较小,但对TN和TP去除效果有显著影响;系统脱氮越完全越有利于除磷,提高内回流、减小外回流可以有效提高工艺的脱氮除磷能力;缺氧池体积占比对氮磷的去除有着重要影响,控制缺氧HRT>3 h可以保证系统具有较高的脱氮效果,而增加好氧池体积不利于氮磷的去除;采用两点进水可一定程度上提高AAO工艺的脱氮效果和处理不稳定水质和高氮负荷水质的能力,维持缺氧池进水0~20%时,可一定程度解决反硝化碳源不足的问题,提升脱氮效果。综合考虑经济效益和去除效果,最终优化的运行参数为R_(内)=250%、R_(外)=50%、V_(厌氧)∶V_(缺氧)∶V_(好氧)=1∶2∶6,运行方式为厌氧/缺氧=9∶1的两点进水模式,此模式可提高脱氮7.4%,并提高了系统抗冲击负荷的能力。

The traditional AAO process has problems such as SRT contradictions,carbon source competition,and return ratio conflicts,which are important reasons restricting the process processing effect.To improve the effect of nitrogen and phosphorus removal in the AAO process,an integrated reactor device was designed in this study.The effects of different reflux ratios,reaction zone volume ratios,and two-point inlet water ratios on nitrogen and phosphorus removal in this process were analyzed.The results showed that the changes of reflux ratio and reaction zone volume had little effect on the removal rate of COD and NH4+-N,but significantly impacted the removal effect of TN and TP.The complete denitrification in the system was more conducive to phosphorus removal.Improving internal reflux and reducing external reflux can improve the process's capacity for nitrogen and phosphorus removal.The proportion of hypoxic tank volume has an important impact on removing nitrogen and phosphorus,and controlling the hypoxia HRT>3 h can ensure that the system has a high denitrification effect,while increasing the volume of the aerobic tank is not conducive to the removal of nitrogen and phosphorus.Using two-point inlet water can improve the denitrification effect of the AAO process.It could deal with unstable water quality and high nitrogen load water quality to a certain extent.The inlet water of the hypoxic pool maintains by 0 to 20%,which can solve the problem of insufficient denitrification carbon source to a certain extent and improve the denitrification effect.Considering the economic benefits and removal effects,the final optimized operating parameters are R within=250%,R outside=50%,V_(anaerobic):V_(hypoxia):V_(aerobic)=1:2:6,and the operating mode is an anaerobic/hypoxic=9:1 two-point water inlet mode,which can improve the nitrogen denitridation by 7.4%and the ability of the system to withstand shock loads.